[illumos-gate merge]

commit ee6ee36a8ff1701c4e61e6f118446b145220478c
    14838 Rename erratum 147 handling
    14839 Untangle erratum 147 from lockstat
    14840 Modernize lockstat probes
    14865 mutex_tryenter:adaptive-acquire probe never fires
commit 64439ec0071c576648f76b4466ad6ee7a580ed33
    14579 expose virtio 9P transport device
commit ec8422d0a51b3bf0b6550dd15f125990a3f73f4c
    7346 beadm list shows duplicates when zone has datasets from multiple pools
commit 46dc144bc2859392d4c62f3e72d661e7b3c22a8e
    14900 ddi_fm_capable(9F) man page does not match source

Conflicts:
    manifest
    usr/src/man/man9f/ddi_fm_init.9f
    usr/src/uts/intel/os/driver_aliases
    usr/src/uts/intel/os/name_to_major

36 files changed, 1866 insertions, 400 deletions

diff --git a/manifest b/manifest
index 6356e0c756..e7c074155f 100644
--- a/manifest
+++ b/manifest
@@ -809,6 +809,7 @@ f kernel/drv/amd64/usbskel 0755 root sys
 f kernel/drv/amd64/usbsksp 0755 root sys
 f kernel/drv/amd64/usbsprl 0755 root sys
 f kernel/drv/amd64/vgatext 0755 root sys
+f kernel/drv/amd64/vio9p 0755 root sys
 f kernel/drv/amd64/vioblk 0755 root sys
 f kernel/drv/amd64/vioif 0755 root sys
 f kernel/drv/amd64/vioscsi 0755 root sys
@@ -4899,6 +4900,7 @@ f usr/include/sys/vfs_opreg.h 0644 root bin
 f usr/include/sys/vfstab.h 0644 root bin
 f usr/include/sys/vgareg.h 0644 root bin
 f usr/include/sys/videodev2.h 0644 root bin
+f usr/include/sys/vio9p.h 0644 root bin
 f usr/include/sys/visual_io.h 0644 root bin
 f usr/include/sys/vlan.h 0644 root bin
 f usr/include/sys/vm.h 0644 root bin
@@ -18988,6 +18990,7 @@ f usr/share/man/man4d/usbftdi.4d 0444 root bin
 f usr/share/man/man4d/usbsacm.4d 0444 root bin
 f usr/share/man/man4d/usbsksp.4d 0444 root bin
 f usr/share/man/man4d/usbsprl.4d 0444 root bin
+f usr/share/man/man4d/vio9p.4d 0444 root bin
 f usr/share/man/man4d/vioblk.4d 0444 root bin
 f usr/share/man/man4d/vioif.4d 0444 root bin
 f usr/share/man/man4d/vioscsi.4d 0444 root bin
diff --git a/usr/src/cmd/devfsadm/misc_link.c b/usr/src/cmd/devfsadm/misc_link.c
index 936560912f..e8b56c7fce 100644
--- a/usr/src/cmd/devfsadm/misc_link.c
+++ b/usr/src/cmd/devfsadm/misc_link.c
@@ -23,6 +23,7 @@
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  * Copyright 2019 Joyent, Inc.
  * Copyright 2022 Garrett D'Amore <garrett@damore.org>
+ * Copyright 2022 Oxide Computer Company
  */
 
 #include <regex.h>
@@ -60,6 +61,7 @@ static int cpuid(di_minor_t minor, di_node_t node);
 static int glvc(di_minor_t minor, di_node_t node);
 static int ses_callback(di_minor_t minor, di_node_t node);
 static int kmdrv_create(di_minor_t minor, di_node_t node);
+static int vio9p_create(di_minor_t minor, di_node_t node);
 
 static devfsadm_create_t misc_cbt[] = {
 	{ "pseudo", "ddi_pseudo", "(^sad$)",
@@ -215,7 +217,10 @@ static devfsadm_create_t misc_cbt[] = {
 	},
 	{ "pseudo", "ddi_pseudo", "overlay",
 	    TYPE_EXACT | DRV_EXACT, ILEVEL_0, minor_name
-	}
+	},
+	{ "9p", "ddi_pseudo", "vio9p",
+	    TYPE_EXACT | DRV_EXACT, ILEVEL_0, vio9p_create,
+	},
 };
 
 DEVFSADM_CREATE_INIT_V0(misc_cbt);
@@ -257,7 +262,10 @@ static devfsadm_remove_t misc_remove_cbt[] = {
 	},
 	{ "pseudo", "^sctp|sctp6$",
 	    RM_PRE | RM_ALWAYS, ILEVEL_0, devfsadm_rm_link
-	}
+	},
+	{ "9p", "^9p/[0-9]+$",
+	    RM_PRE | RM_HOT | RM_ALWAYS, ILEVEL_0, devfsadm_rm_all
+	},
 };
 
 /* Rules for gpio devices */
@@ -643,6 +651,26 @@ av_create(di_minor_t minor, di_node_t node)
 }
 
 /*
+ * Create device nodes for Virtio 9P channels:
+ *	/dev/9p/[0-9]+
+ */
+static int
+vio9p_create(di_minor_t minor, di_node_t node)
+{
+	char *minor_name = di_minor_name(minor);
+	char path[PATH_MAX + 1];
+
+	if (minor_name == NULL || strcmp(minor_name, "9p") != 0) {
+		return (DEVFSADM_CONTINUE);
+	}
+
+	(void) snprintf(path, sizeof (path), "9p/%d", di_instance(node));
+	(void) devfsadm_mklink(path, node, minor, 0);
+
+	return (DEVFSADM_CONTINUE);
+}
+
+/*
  * Creates /dev/lom and /dev/tsalarm:ctl for tsalarm node
  */
 static int
diff --git a/usr/src/lib/libbe/common/be_activate.c b/usr/src/lib/libbe/common/be_activate.c
index 4ec8f055e2..581ddc41c2 100644
--- a/usr/src/lib/libbe/common/be_activate.c
+++ b/usr/src/lib/libbe/common/be_activate.c
@@ -26,7 +26,7 @@
 /*
  * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
  * Copyright 2016 Toomas Soome <tsoome@me.com>
- * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #include <assert.h>
@@ -266,7 +266,12 @@ _be_activate(char *be_name, be_nextboot_state_t nextboot)
 		return (ret);
 	}
 
-	be_make_root_ds(cb.obe_zpool, cb.obe_name, root_ds, sizeof (root_ds));
+	if ((ret = be_make_root_ds(cb.obe_zpool, cb.obe_name, root_ds,
+	    sizeof (root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, cb.obe_zpool, cb.obe_name);
+		return (ret);
+	}
 	cb.obe_root_ds = strdup(root_ds);
 
 	if (getzoneid() == GLOBAL_ZONEID) {
@@ -573,8 +578,13 @@ set_canmount(be_node_list_t *be_nodes, char *value)
 	while (list != NULL) {
 		be_dataset_list_t *datasets = list->be_node_datasets;
 
-		be_make_root_ds(list->be_rpool, list->be_node_name, ds_path,
-		    sizeof (ds_path));
+		if ((err = be_make_root_ds(list->be_rpool, list->be_node_name,
+		    ds_path, sizeof (ds_path))) != BE_SUCCESS) {
+			be_print_err(gettext("%s: failed to get BE container "
+			    "dataset for %s/%s\n"), __func__,
+			    list->be_rpool, list->be_node_name);
+			return (err);
+		}
 
 		if ((zhp = zfs_open(g_zfs, ds_path, ZFS_TYPE_DATASET)) ==
 		    NULL) {
@@ -605,9 +615,14 @@ set_canmount(be_node_list_t *be_nodes, char *value)
 		ZFS_CLOSE(zhp);
 
 		while (datasets != NULL) {
-			be_make_root_ds(list->be_rpool,
+			if ((err = be_make_root_ds(list->be_rpool,
 			    datasets->be_dataset_name, ds_path,
-			    sizeof (ds_path));
+			    sizeof (ds_path))) != BE_SUCCESS) {
+				be_print_err(gettext("%s: failed to get BE "
+				    "container dataset for %s/%s\n"), __func__,
+				    list->be_rpool, datasets->be_dataset_name);
+				return (err);
+			}
 
 			if ((zhp = zfs_open(g_zfs, ds_path, ZFS_TYPE_DATASET))
 			    == NULL) {
diff --git a/usr/src/lib/libbe/common/be_create.c b/usr/src/lib/libbe/common/be_create.c
index 4158ddb677..62f5bfe112 100644
--- a/usr/src/lib/libbe/common/be_create.c
+++ b/usr/src/lib/libbe/common/be_create.c
@@ -24,7 +24,7 @@
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
  * Copyright (c) 2016 Martin Matuska. All rights reserved.
- * Copyright 2021 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*
@@ -206,8 +206,12 @@ be_init(nvlist_t *be_attrs)
 	}
 
 	/* Generate string for BE's root dataset */
-	be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
-	    sizeof (nbe_root_ds));
+	if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
+	    sizeof (nbe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.nbe_zpool, bt.nbe_name);
+		return (ret);
+	}
 
 	/*
 	 * Create property list for new BE root dataset.  If some
@@ -446,8 +450,12 @@ be_destroy(nvlist_t *be_attrs)
 	}
 
 	/* Generate string for obe_name's root dataset */
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
-	    sizeof (obe_root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
+	    sizeof (obe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = obe_root_ds;
 
 	if (getzoneid() != GLOBAL_ZONEID) {
@@ -780,10 +788,28 @@ be_copy(nvlist_t *be_attrs)
 	}
 
 	/*
+	 * If an auto named BE is desired, it must be in the same
+	 * pool as the original BE.
+	 */
+	if (bt.nbe_name == NULL && bt.nbe_zpool != NULL) {
+		be_print_err(gettext("be_copy: cannot specify pool "
+		    "name when creating an auto named BE\n"));
+		ret = BE_ERR_INVAL;
+		goto done;
+	}
+
+	/*
+	 * If the zpool name to create new BE in is not provided,
+	 * create the new BE in the original BE's pool.
+	 */
+	if (bt.nbe_zpool == NULL)
+		bt.nbe_zpool = bt.obe_zpool;
+
+	/*
 	 * If new BE name provided, validate the BE name and then verify
 	 * that new BE name doesn't already exist in some pool.
 	 */
-	if (bt.nbe_name) {
+	if (bt.nbe_name != NULL) {
 		/* Validate original BE name */
 		if (!be_valid_be_name(bt.nbe_name)) {
 			be_print_err(gettext("be_copy: "
@@ -808,8 +834,13 @@ be_copy(nvlist_t *be_attrs)
 				goto done;
 			}
 		} else {
-			be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
-			    sizeof (nbe_root_ds));
+			if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name,
+			    nbe_root_ds, sizeof (nbe_root_ds))) != BE_SUCCESS) {
+				be_print_err(gettext("%s: failed to get BE "
+				    "container dataset for %s/%s\n"), __func__,
+				    bt.nbe_zpool, bt.nbe_name);
+				goto done;
+			}
 			if (zfs_dataset_exists(g_zfs, nbe_root_ds,
 			    ZFS_TYPE_FILESYSTEM)) {
 				be_print_err(gettext("be_copy: BE (%s) already "
@@ -820,17 +851,6 @@ be_copy(nvlist_t *be_attrs)
 		}
 	} else {
 		/*
-		 * If an auto named BE is desired, it must be in the same
-		 * pool is the original BE.
-		 */
-		if (bt.nbe_zpool != NULL) {
-			be_print_err(gettext("be_copy: cannot specify pool "
-			    "name when creating an auto named BE\n"));
-			ret = BE_ERR_INVAL;
-			goto done;
-		}
-
-		/*
 		 * Generate auto named BE
 		 */
 		if ((bt.nbe_name = be_auto_be_name(bt.obe_name))
@@ -844,19 +864,19 @@ be_copy(nvlist_t *be_attrs)
 		autoname = B_TRUE;
 	}
 
-	/*
-	 * If zpool name to create new BE in is not provided,
-	 * create new BE in original BE's pool.
-	 */
-	if (bt.nbe_zpool == NULL) {
-		bt.nbe_zpool = bt.obe_zpool;
-	}
-
 	/* Get root dataset names for obe_name and nbe_name */
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
-	    sizeof (obe_root_ds));
-	be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
-	    sizeof (nbe_root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
+	    sizeof (obe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		goto done;
+	}
+	if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
+	    sizeof (nbe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.nbe_zpool, bt.nbe_name);
+		goto done;
+	}
 
 	bt.obe_root_ds = obe_root_ds;
 	bt.nbe_root_ds = nbe_root_ds;
@@ -966,8 +986,15 @@ be_copy(nvlist_t *be_attrs)
 				 * Regenerate string for new BE's
 				 * root dataset name
 				 */
-				be_make_root_ds(bt.nbe_zpool, bt.nbe_name,
-				    nbe_root_ds, sizeof (nbe_root_ds));
+				if ((ret = be_make_root_ds(bt.nbe_zpool,
+				    bt.nbe_name, nbe_root_ds,
+				    sizeof (nbe_root_ds))) != BE_SUCCESS) {
+					be_print_err(gettext(
+					    "%s: failed to get BE container "
+					    "dataset for %s/%s\n"), __func__,
+					    bt.nbe_zpool, bt.nbe_name);
+					goto done;
+				}
 				bt.nbe_root_ds = nbe_root_ds;
 
 				/*
@@ -1122,10 +1149,18 @@ be_copy(nvlist_t *be_attrs)
 	 * Update new BE's vfstab.
 	 */
 
-	be_make_root_container_ds(bt.obe_zpool, obe_root_container,
-	    sizeof (obe_root_container));
-	be_make_root_container_ds(bt.nbe_zpool, nbe_root_container,
-	    sizeof (nbe_root_container));
+	if ((ret = be_make_root_container_ds(bt.obe_zpool, obe_root_container,
+	    sizeof (obe_root_container))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, bt.obe_zpool);
+		goto done;
+	}
+	if ((ret = be_make_root_container_ds(bt.nbe_zpool, nbe_root_container,
+	    sizeof (nbe_root_container))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, bt.nbe_zpool);
+		goto done;
+	}
 
 	if ((ret = be_update_vfstab(bt.nbe_name, obe_root_container,
 	    nbe_root_container, &fld, new_mp)) != BE_SUCCESS) {
@@ -1258,11 +1293,15 @@ be_find_zpool_callback(zpool_handle_t *zlp, void *data)
 	be_transaction_data_t	*bt = data;
 	const char		*zpool =  zpool_get_name(zlp);
 	char			be_root_ds[MAXPATHLEN];
+	int			ret = 0;
 
 	/*
 	 * Generate string for the BE's root dataset
 	 */
-	be_make_root_ds(zpool, bt->obe_name, be_root_ds, sizeof (be_root_ds));
+	if (be_make_root_ds(zpool, bt->obe_name, be_root_ds,
+	    sizeof (be_root_ds)) != BE_SUCCESS) {
+		goto out;
+	}
 
 	/*
 	 * Check if dataset exists
@@ -1270,12 +1309,12 @@ be_find_zpool_callback(zpool_handle_t *zlp, void *data)
 	if (zfs_dataset_exists(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM)) {
 		/* BE's root dataset exists in zpool */
 		bt->obe_zpool = strdup(zpool);
-		zpool_close(zlp);
-		return (1);
+		ret = 1;
 	}
 
+out:
 	zpool_close(zlp);
-	return (0);
+	return (ret);
 }
 
 /*
@@ -1297,23 +1336,27 @@ be_exists_callback(zpool_handle_t *zlp, void *data)
 	const char	*zpool = zpool_get_name(zlp);
 	char		*be_name = data;
 	char		be_root_ds[MAXPATHLEN];
+	int		ret = 0;
 
 	/*
 	 * Generate string for the BE's root dataset
 	 */
-	be_make_root_ds(zpool, be_name, be_root_ds, sizeof (be_root_ds));
+	if (be_make_root_ds(zpool, be_name, be_root_ds,
+	    sizeof (be_root_ds)) != BE_SUCCESS) {
+		goto out;
+	}
 
 	/*
 	 * Check if dataset exists
 	 */
 	if (zfs_dataset_exists(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM)) {
 		/* BE's root dataset exists in zpool */
-		zpool_close(zlp);
-		return (1);
+		ret = 1;
 	}
 
+out:
 	zpool_close(zlp);
-	return (0);
+	return (ret);
 }
 
 /*
@@ -1779,8 +1822,12 @@ be_destroy_zone_roots(char *zonepath_ds, be_destroy_data_t *dd)
 	int		ret = BE_SUCCESS;
 
 	/* Generate string for the root container dataset for this zone. */
-	be_make_container_ds(zonepath_ds, zone_container_ds,
-	    sizeof (zone_container_ds));
+	if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
+	    sizeof (zone_container_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, zonepath_ds);
+		return (ret);
+	}
 
 	/* Get handle to this zone's root container dataset. */
 	if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
@@ -2049,8 +2096,12 @@ be_copy_zones(char *obe_name, char *obe_root_ds, char *nbe_root_ds)
 			goto done;
 		}
 
-		be_make_container_ds(zonepath_ds, zone_container_ds,
-		    sizeof (zone_container_ds));
+		if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
+		    sizeof (zone_container_ds))) != BE_SUCCESS) {
+			be_print_err(gettext("%s: failed to get BE container "
+			    "dataset for %s\n"), __func__, zonepath_ds);
+			goto done;
+		}
 
 		if ((z_zhp = zfs_open(g_zfs, zoneroot_ds,
 		    ZFS_TYPE_FILESYSTEM)) == NULL) {
@@ -2901,8 +2952,12 @@ be_create_container_ds(char *zpool)
 	char		be_container_ds[MAXPATHLEN];
 
 	/* Generate string for BE container dataset for this pool */
-	be_make_container_ds(zpool, be_container_ds,
-	    sizeof (be_container_ds));
+	if (be_make_container_ds(zpool, be_container_ds,
+	    sizeof (be_container_ds)) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, zpool);
+		return (B_FALSE);
+	}
 
 	if (!zfs_dataset_exists(g_zfs, be_container_ds, ZFS_TYPE_FILESYSTEM)) {
 
diff --git a/usr/src/lib/libbe/common/be_list.c b/usr/src/lib/libbe/common/be_list.c
index 3e0833ea83..85b62eff38 100644
--- a/usr/src/lib/libbe/common/be_list.c
+++ b/usr/src/lib/libbe/common/be_list.c
@@ -29,7 +29,7 @@
  * Copyright 2015 Toomas Soome <tsoome@me.com>
  * Copyright 2015 Gary Mills
  * Copyright (c) 2016 Martin Matuska. All rights reserved.
- * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #include <assert.h>
@@ -445,8 +445,12 @@ be_get_list_callback(zpool_handle_t *zlp, void *data)
 	/*
 	 * Generate string for the BE container dataset
 	 */
-	be_make_container_ds(rpool, be_container_ds,
-	    sizeof (be_container_ds));
+	if (be_make_container_ds(rpool, be_container_ds,
+	    sizeof (be_container_ds)) != BE_SUCCESS) {
+		/* Move on to the next pool */
+		zpool_close(zlp);
+		return (0);
+	}
 
 	/*
 	 * If a BE name was specified we use it's root dataset in place of
@@ -454,12 +458,17 @@ be_get_list_callback(zpool_handle_t *zlp, void *data)
 	 * the information for the specified BE.
 	 */
 	if (cb->be_name != NULL) {
+		int rv;
+
 		if (!be_valid_be_name(cb->be_name))
 			return (BE_ERR_INVAL);
 		/*
 		 * Generate string for the BE root dataset
 		 */
-		be_make_root_ds(rpool, cb->be_name, be_ds, sizeof (be_ds));
+		if ((rv = be_make_root_ds(rpool, cb->be_name, be_ds,
+		    sizeof (be_ds))) != BE_SUCCESS) {
+			return (rv);
+		}
 		open_ds = be_ds;
 	} else {
 		open_ds = be_container_ds;
diff --git a/usr/src/lib/libbe/common/be_mount.c b/usr/src/lib/libbe/common/be_mount.c
index 98c861fca4..672424d1f2 100644
--- a/usr/src/lib/libbe/common/be_mount.c
+++ b/usr/src/lib/libbe/common/be_mount.c
@@ -24,6 +24,7 @@
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  * Copyright 2015 EveryCity Ltd.
  * Copyright (c) 2015 by Delphix. All rights reserved.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*
@@ -277,8 +278,12 @@ _be_mount(char *be_name, char **altroot, int flags)
 	}
 
 	/* Generate string for obe_name's root dataset */
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
-	    sizeof (obe_root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
+	    sizeof (obe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = obe_root_ds;
 
 	/* Get handle to BE's root dataset */
@@ -448,8 +453,12 @@ _be_unmount(char *be_name, int flags)
 	}
 
 	/* Generate string for obe_name's root dataset */
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
-	    sizeof (obe_root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
+	    sizeof (obe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = obe_root_ds;
 
 	/* Get handle to BE's root dataset */
@@ -1565,15 +1574,13 @@ iter_shared_fs_callback(zfs_handle_t *zhp, void *data)
 	pool = strtok(tmp_name, "/");
 
 	if (pool) {
-		/* Get the name of this pool's container dataset */
-		be_make_container_ds(pool, container_ds,
-		    sizeof (container_ds));
-
 		/*
 		 * If what we're processing is this pool's BE container
 		 * dataset, skip it.
 		 */
-		if (strcmp(name, container_ds) == 0) {
+		if (be_make_container_ds(pool, container_ds,
+		    sizeof (container_ds)) == BE_SUCCESS &&
+		    strcmp(name, container_ds) == 0) {
 			ZFS_CLOSE(zhp);
 			return (0);
 		}
diff --git a/usr/src/lib/libbe/common/be_rename.c b/usr/src/lib/libbe/common/be_rename.c
index f0cd781b22..87dadefaff 100644
--- a/usr/src/lib/libbe/common/be_rename.c
+++ b/usr/src/lib/libbe/common/be_rename.c
@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012 by Delphix. All rights reserved.
- * Copyright 2021 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #include <assert.h>
@@ -150,9 +150,19 @@ be_rename(nvlist_t *be_attrs)
 	/* New BE will reside in the same zpool as orig BE */
 	bt.nbe_zpool = bt.obe_zpool;
 
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds, sizeof (root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds,
+	    sizeof (root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		goto done;
+	};
 	bt.obe_root_ds = strdup(root_ds);
-	be_make_root_ds(bt.nbe_zpool, bt.nbe_name, root_ds, sizeof (root_ds));
+	if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name, root_ds,
+	    sizeof (root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.nbe_zpool, bt.nbe_name);
+		goto done;
+	}
 	bt.nbe_root_ds = strdup(root_ds);
 
 	/*
@@ -248,8 +258,12 @@ be_rename(nvlist_t *be_attrs)
 	 * Since the new and old BEs reside in the same pool (see above),
 	 * the same variable can be used for the container for both.
 	 */
-	be_make_root_container_ds(bt.obe_zpool, be_root_container,
-	    sizeof (be_root_container));
+	if ((ret = be_make_root_container_ds(bt.obe_zpool, be_root_container,
+	    sizeof (be_root_container))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, bt.obe_zpool);
+		goto done;
+	}
 
 	if ((ret = be_update_vfstab(bt.nbe_name, be_root_container,
 	    be_root_container, &fld, mp)) != BE_SUCCESS) {
diff --git a/usr/src/lib/libbe/common/be_snapshot.c b/usr/src/lib/libbe/common/be_snapshot.c
index a4e2c79e5a..92fd2ae96d 100644
--- a/usr/src/lib/libbe/common/be_snapshot.c
+++ b/usr/src/lib/libbe/common/be_snapshot.c
@@ -25,6 +25,7 @@
 
 /*
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*
@@ -88,7 +89,7 @@ be_create_snapshot(nvlist_t *be_attrs)
 	char		*snap_name = NULL;
 	char		*policy = NULL;
 	boolean_t	autoname = B_FALSE;
-	int 		ret = BE_SUCCESS;
+	int		ret = BE_SUCCESS;
 
 	/* Initialize libzfs handle */
 	if (!be_zfs_init())
@@ -184,7 +185,7 @@ be_destroy_snapshot(nvlist_t *be_attrs)
 {
 	char	*be_name = NULL;
 	char	*snap_name = NULL;
-	int 	ret = BE_SUCCESS;
+	int	ret = BE_SUCCESS;
 
 	/* Initialize libzfs handle */
 	if (!be_zfs_init())
@@ -319,8 +320,12 @@ be_rollback(nvlist_t *be_attrs)
 	}
 
 	/* Generate string for BE's root dataset */
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
-	    sizeof (obe_root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
+	    sizeof (obe_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = obe_root_ds;
 
 	if (getzoneid() != GLOBAL_ZONEID) {
@@ -434,8 +439,12 @@ _be_create_snapshot(char *be_name, char **snap_name, char *policy)
 		return (zfs_err_to_be_err(g_zfs));
 	}
 
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds,
-	    sizeof (root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds,
+	    sizeof (root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = root_ds;
 
 	if (getzoneid() != GLOBAL_ZONEID) {
@@ -662,8 +671,12 @@ _be_destroy_snapshot(char *be_name, char *snap_name)
 		return (zfs_err_to_be_err(g_zfs));
 	}
 
-	be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds,
-	    sizeof (root_ds));
+	if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, root_ds,
+	    sizeof (root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
+		return (ret);
+	}
 	bt.obe_root_ds = root_ds;
 
 	zhp = zfs_open(g_zfs, bt.obe_root_ds, ZFS_TYPE_DATASET);
diff --git a/usr/src/lib/libbe/common/be_utils.c b/usr/src/lib/libbe/common/be_utils.c
index 17d43ee195..8b95f7bc91 100644
--- a/usr/src/lib/libbe/common/be_utils.c
+++ b/usr/src/lib/libbe/common/be_utils.c
@@ -24,7 +24,7 @@
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  * Copyright 2016 Toomas Soome <tsoome@me.com>
  * Copyright (c) 2015 by Delphix. All rights reserved.
- * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  * Copyright (c) 2018, Joyent, Inc.
  */
 
@@ -439,17 +439,19 @@ be_get_defaults(struct be_defaults *defaults)
  *		be_root_ds - pointer to buffer to return BE root dataset in.
  *		be_root_ds_size - size of be_root_ds
  * Returns:
- *		None
+ *		BE_SUCCESS - Success
+ *		be_errno_t - Failure
  * Scope:
  *		Semi-private (library wide use only)
  */
-void
+int
 be_make_root_ds(const char *zpool, const char *be_name, char *be_root_ds,
     int be_root_ds_size)
 {
 	struct be_defaults be_defaults;
 	be_get_defaults(&be_defaults);
-	char	*root_ds = NULL;
+
+	assert(zpool != NULL);
 
 	if (getzoneid() == GLOBAL_ZONEID) {
 		if (be_defaults.be_deflt_rpool_container) {
@@ -461,18 +463,30 @@ be_make_root_ds(const char *zpool, const char *be_name, char *be_root_ds,
 		}
 	} else {
 		/*
-		 * In non-global zone we can use path from mounted root dataset
-		 * to generate BE's root dataset string.
+		 * In a non-global zone we can use the path from the mounted
+		 * root dataset to generate the BE's root dataset string.
 		 */
-		if ((root_ds = be_get_ds_from_dir("/")) != NULL) {
-			(void) snprintf(be_root_ds, be_root_ds_size, "%s/%s",
-			    dirname(root_ds), be_name);
-		} else {
+		char *root_ds = be_get_ds_from_dir("/");
+
+		if (root_ds == NULL) {
 			be_print_err(gettext("be_make_root_ds: zone root "
 			    "dataset is not mounted\n"));
-			return;
+			return (BE_ERR_NOTMOUNTED);
 		}
+		if (strncmp(root_ds, zpool, strlen(zpool)) != 0 ||
+		    root_ds[strlen(zpool)] != '/') {
+			/*
+			 * This pool is not the one that contains the zone
+			 * root.
+			 */
+			return (BE_ERR_ACCESS);
+		}
+
+		(void) snprintf(be_root_ds, be_root_ds_size, "%s/%s",
+		    dirname(root_ds), be_name);
 	}
+
+	return (BE_SUCCESS);
 }
 
 /*
@@ -484,17 +498,17 @@ be_make_root_ds(const char *zpool, const char *be_name, char *be_root_ds,
  *			dataset in.
  *		container_ds_size - size of container_ds
  * Returns:
- *		None
+ *		BE_SUCCESS - Success
+ *		be_errno_t - Failure
  * Scope:
  *		Semi-private (library wide use only)
  */
-void
-be_make_container_ds(const char *zpool,  char *container_ds,
+int
+be_make_container_ds(const char *zpool, char *container_ds,
     int container_ds_size)
 {
 	struct be_defaults be_defaults;
 	be_get_defaults(&be_defaults);
-	char	*root_ds = NULL;
 
 	if (getzoneid() == GLOBAL_ZONEID) {
 		if (be_defaults.be_deflt_rpool_container) {
@@ -505,15 +519,26 @@ be_make_container_ds(const char *zpool,  char *container_ds,
 			    "%s/%s", zpool, BE_CONTAINER_DS_NAME);
 		}
 	} else {
-		if ((root_ds = be_get_ds_from_dir("/")) != NULL) {
-			(void) strlcpy(container_ds, dirname(root_ds),
-			    container_ds_size);
-		} else {
+		char *root_ds = be_get_ds_from_dir("/");
+
+		if (root_ds == NULL) {
 			be_print_err(gettext("be_make_container_ds: zone root "
 			    "dataset is not mounted\n"));
-			return;
+			return (BE_ERR_NOTMOUNTED);
+		}
+		if (strncmp(root_ds, zpool, strlen(zpool)) != 0 ||
+		    root_ds[strlen(zpool)] != '/') {
+			/*
+			 * This pool is not the one that contains the zone
+			 * root.
+			 */
+			return (BE_ERR_ACCESS);
 		}
+		(void) strlcpy(container_ds, dirname(root_ds),
+		    container_ds_size);
 	}
+
+	return (BE_SUCCESS);
 }
 
 /*
@@ -525,17 +550,22 @@ be_make_container_ds(const char *zpool,  char *container_ds,
  *		container_ds - pointer to buffer in which to return result
  *		container_ds_size - size of container_ds
  * Returns:
- *		None
+ *		BE_SUCCESS - Success
+ *		be_errno_t - Failure
  * Scope:
  *		Semi-private (library wide use only)
  */
-void
+int
 be_make_root_container_ds(const char *zpool, char *container_ds,
     int container_ds_size)
 {
 	char *root;
+	int ret;
 
-	be_make_container_ds(zpool, container_ds, container_ds_size);
+	if ((ret = be_make_container_ds(zpool, container_ds,
+	    container_ds_size)) != BE_SUCCESS) {
+		return (ret);
+	}
 
 	/* If the container DS ends with /ROOT, remove it.  */
 
@@ -543,6 +573,8 @@ be_make_root_container_ds(const char *zpool, char *container_ds,
 	    strcmp(root + 1, BE_CONTAINER_DS_NAME) == 0) {
 		*root = '\0';
 	}
+
+	return (BE_SUCCESS);
 }
 
 /*
@@ -714,7 +746,12 @@ be_append_menu(char *be_name, char *be_root_pool, char *boot_pool,
 		    "%s%s", pool_mntpnt, BE_SPARC_MENU);
 	}
 
-	be_make_root_ds(be_root_pool, be_name, be_root_ds, sizeof (be_root_ds));
+	if ((ret = be_make_root_ds(be_root_pool, be_name, be_root_ds,
+	    sizeof (be_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, be_root_pool, be_name);
+		goto cleanup;
+	}
 
 	/*
 	 * Iterate through menu first to make sure the BE doesn't already
@@ -969,7 +1006,12 @@ be_remove_menu(char *be_name, char *be_root_pool, char *boot_pool)
 		boot_pool = be_root_pool;
 
 	/* Get name of BE's root dataset */
-	be_make_root_ds(be_root_pool, be_name, be_root_ds, sizeof (be_root_ds));
+	if ((ret = be_make_root_ds(be_root_pool, be_name, be_root_ds,
+	    sizeof (be_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, be_root_pool, be_name);
+		return (ret);
+	}
 
 	/* Get handle to pool dataset */
 	if ((zhp = zfs_open(g_zfs, be_root_pool, ZFS_TYPE_DATASET)) == NULL) {
@@ -1579,7 +1621,12 @@ be_change_grub_default(char *be_name, char *be_root_pool)
 	}
 
 	/* Generate string for BE's root dataset */
-	be_make_root_ds(be_root_pool, be_name, be_root_ds, sizeof (be_root_ds));
+	if ((ret = be_make_root_ds(be_root_pool, be_name, be_root_ds,
+	    sizeof (be_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, be_root_pool, be_name);
+		return (ret);
+	}
 
 	/* Get handle to pool dataset */
 	if ((zhp = zfs_open(g_zfs, be_root_pool, ZFS_TYPE_DATASET)) == NULL) {
@@ -1848,10 +1895,18 @@ be_update_menu(char *be_orig_name, char *be_new_name, char *be_root_pool,
 		    "%s%s", pool_mntpnt, BE_SPARC_MENU);
 	}
 
-	be_make_root_ds(be_root_pool, be_orig_name, be_root_ds,
-	    sizeof (be_root_ds));
-	be_make_root_ds(be_root_pool, be_new_name, be_new_root_ds,
-	    sizeof (be_new_root_ds));
+	if ((ret = be_make_root_ds(be_root_pool, be_orig_name, be_root_ds,
+	    sizeof (be_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, be_root_pool, be_orig_name);
+		goto cleanup;
+	}
+	if ((ret = be_make_root_ds(be_root_pool, be_new_name, be_new_root_ds,
+	    sizeof (be_new_root_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s/%s\n"), __func__, be_root_pool, be_new_name);
+		goto cleanup;
+	}
 
 	if ((ret = be_open_menu(be_root_pool, menu_file,
 	    &menu_fp, "r", B_TRUE)) != BE_SUCCESS) {
@@ -2714,24 +2769,14 @@ be_zpool_find_current_be_callback(zpool_handle_t *zlp, void *data)
 	zfs_handle_t		*zhp = NULL;
 	const char		*zpool =  zpool_get_name(zlp);
 	char			be_container_ds[MAXPATHLEN];
-	char			*zpath = NULL;
 
 	/*
 	 * Generate string for BE container dataset
 	 */
-	if (getzoneid() != GLOBAL_ZONEID) {
-		if ((zpath = be_get_ds_from_dir("/")) != NULL) {
-			(void) strlcpy(be_container_ds, dirname(zpath),
-			    sizeof (be_container_ds));
-		} else {
-			be_print_err(gettext(
-			    "be_zpool_find_current_be_callback: "
-			    "zone root dataset is not mounted\n"));
-			return (0);
-		}
-	} else {
-		be_make_container_ds(zpool, be_container_ds,
-		    sizeof (be_container_ds));
+	if (be_make_container_ds(zpool, be_container_ds,
+	    sizeof (be_container_ds)) != BE_SUCCESS) {
+		zpool_close(zlp);
+		return (0);
 	}
 
 	/*
@@ -2865,7 +2910,10 @@ be_check_be_roots_callback(zpool_handle_t *zlp, void *data)
 	char		be_container_ds[MAXPATHLEN];
 
 	/* Generate string for this pool's BE root container dataset */
-	be_make_container_ds(zpool, be_container_ds, sizeof (be_container_ds));
+	if (be_make_container_ds(zpool, be_container_ds,
+	    sizeof (be_container_ds)) != BE_SUCCESS) {
+		return (0);
+	}
 
 	/*
 	 * If dataset lives under the BE root container dataset
@@ -3420,6 +3468,7 @@ update_dataset(char *dataset, int dataset_len, char *be_name,
 {
 	char	*ds = NULL;
 	char	*sub_ds = NULL;
+	int	ret;
 
 	/* Tear off the BE container dataset */
 	if ((ds = be_make_name_from_ds(dataset, old_rc_loc)) == NULL) {
@@ -3430,7 +3479,10 @@ update_dataset(char *dataset, int dataset_len, char *be_name,
 	sub_ds = strchr(ds, '/');
 
 	/* Generate the BE root dataset name */
-	be_make_root_ds(new_rc_loc, be_name, dataset, dataset_len);
+	if ((ret = be_make_root_ds(new_rc_loc, be_name, dataset,
+	    dataset_len)) != BE_SUCCESS) {
+		return (ret);
+	}
 
 	/* If a subordinate dataset name was found, append it */
 	if (sub_ds != NULL)
diff --git a/usr/src/lib/libbe/common/be_zones.c b/usr/src/lib/libbe/common/be_zones.c
index e257b62125..665db1b1d0 100644
--- a/usr/src/lib/libbe/common/be_zones.c
+++ b/usr/src/lib/libbe/common/be_zones.c
@@ -25,6 +25,7 @@
 
 /*
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*
@@ -135,9 +136,13 @@ be_find_active_zone_root(zfs_handle_t *be_zhp, char *zonepath_ds,
 		}
 	}
 
-	/* Generate string for the root container dataset  for this zone. */
-	be_make_container_ds(zonepath_ds, zone_container_ds,
-	    sizeof (zone_container_ds));
+	/* Generate string for the root container dataset for this zone. */
+	if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
+	    sizeof (zone_container_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, zonepath_ds);
+		return (ret);
+	}
 
 	/* Get handle to this zone's root container dataset */
 	if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
@@ -205,8 +210,12 @@ be_find_mounted_zone_root(char *zone_altroot, char *zonepath_ds,
 	int		zret = 0;
 
 	/* Generate string for the root container dataset for this zone. */
-	be_make_container_ds(zonepath_ds, zone_container_ds,
-	    sizeof (zone_container_ds));
+	if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
+	    sizeof (zone_container_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, zonepath_ds);
+		return (ret);
+	}
 
 	/* Get handle to this zone's root container dataset. */
 	if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
@@ -293,8 +302,12 @@ be_zone_supported(char *zonepath_ds)
 	 * Make sure the zonepath has a zone root container dataset
 	 * underneath it.
 	 */
-	be_make_container_ds(zonepath_ds, zone_container_ds,
-	    sizeof (zone_container_ds));
+	if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
+	    sizeof (zone_container_ds))) != BE_SUCCESS) {
+		be_print_err(gettext("%s: failed to get BE container dataset "
+		    "for %s\n"), __func__, zonepath_ds);
+		return (B_FALSE);
+	}
 
 	if (!zfs_dataset_exists(g_zfs, zone_container_ds,
 	    ZFS_TYPE_FILESYSTEM)) {
diff --git a/usr/src/lib/libbe/common/libbe_priv.h b/usr/src/lib/libbe/common/libbe_priv.h
index ace201577f..dd73e33bb1 100644
--- a/usr/src/lib/libbe/common/libbe_priv.h
+++ b/usr/src/lib/libbe/common/libbe_priv.h
@@ -24,7 +24,7 @@
  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  * Copyright 2016 Toomas Soome <tsoome@me.com>
  * Copyright (c) 2015 by Delphix. All rights reserved.
- * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #ifndef	_LIBBE_PRIV_H
@@ -179,9 +179,9 @@ int _be_destroy_snapshot(char *, char *);
 /* be_utils.c */
 boolean_t be_zfs_init(void);
 void be_zfs_fini(void);
-void be_make_root_ds(const char *, const char *, char *, int);
-void be_make_container_ds(const char *, char *, int);
-void be_make_root_container_ds(const char *, char *, int);
+int be_make_root_ds(const char *, const char *, char *, int);
+int be_make_container_ds(const char *, char *, int);
+int be_make_root_container_ds(const char *, char *, int);
 char *be_make_name_from_ds(const char *, char *);
 int be_append_menu(char *, char *, char *, char *, char *);
 int be_remove_menu(char *, char *, char *);
diff --git a/usr/src/man/man4d/Makefile b/usr/src/man/man4d/Makefile
index 8462b451d6..88a0b92076 100644
--- a/usr/src/man/man4d/Makefile
+++ b/usr/src/man/man4d/Makefile
@@ -16,8 +16,8 @@
 # Copyright 2016 Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
 # Copyright 2018 Nexenta Systems, Inc.
 # Copyright 2020 Peter Tribble
-# Copyright 2021 Oxide Computer Company
 # Copyright 2022 RackTop Systems, Inc.
+# Copyright 2022 Oxide Computer Company
 #
 
 include		$(SRC)/Makefile.master
@@ -241,6 +241,7 @@ i386_MANFILES=	ahci.4d		\
 		ural.4d		\
 		urtw.4d		\
 		usmn.4d		\
+		vio9p.4d	\
 		vioblk.4d	\
 		vioif.4d	\
 		vioscsi.4d	\
diff --git a/usr/src/man/man4d/vio9p.4d b/usr/src/man/man4d/vio9p.4d
new file mode 100644
index 0000000000..80952da799
--- /dev/null
+++ b/usr/src/man/man4d/vio9p.4d
@@ -0,0 +1,141 @@
+.\"
+.\" This file and its contents are supplied under the terms of the
+.\" Common Development and Distribution License ("CDDL"), version 1.0.
+.\" You may only use this file in accordance with the terms of version
+.\" 1.0 of the CDDL.
+.\"
+.\" A full copy of the text of the CDDL should have accompanied this
+.\" source.  A copy of the CDDL is also available via the Internet at
+.\" http://www.illumos.org/license/CDDL.
+.\"
+.\"
+.\" Copyright 2022 Oxide Computer Company
+.\"
+.Dd August 1, 2022
+.Dt VIO9P 4D
+.Os
+.Sh NAME
+.Nm vio9p
+.Nd Virtio 9P Transport Driver
+.Sh SYNOPSIS
+.Pa /dev/9p/*
+.Sh DESCRIPTION
+The
+.Nm
+driver provides access to 9P transport devices commonly used by hypervisors
+and emulators to expose a shared file system.
+.Pp
+The
+.Nm
+driver is not a
+.Sy Committed
+interface, and may change at any time.
+.Sh APPLICATION PROGRAMMING INTERFACE
+Each device corresponds to a specific 9P channel, providing exclusive access to
+one consumer at a time.
+The device may be opened with an
+.Xr open 2
+call, which must include at least the
+.Dv O_EXCL
+and
+.Dv O_RDWR
+flags.
+The
+.Dv O_NONBLOCK
+or
+.Dv O_NDELAY
+flags may be used if non-blocking reads and writes are required.
+.Pp
+Once open,
+.Xr read 2
+and
+.Xr write 2
+calls may be made against the resulting file descriptor.
+Writes represent a 9P request message sent to the hypervisor, and reads
+represent responses to those requests.
+.Pp
+Unlike with other transports like TCP, the channel is not explicitly reset when
+the device is opened or closed.
+After a call to
+.Xr open 2 ,
+the application should use a
+.Sy version
+message to open a new session.
+This will explicitly discard any previous session, clunking any active fids in
+the process and negotiating an appropriate protocol version with the
+hypervisor.
+It is likely also appropriate to do this as part of closing the device, to
+allow the hypervisor to free any session tracking resources.
+.Pp
+Writes must be well-formed 9P messages, conforming to whichever 9P protocol
+specification is used by the hypervisor.
+In particular, each message must include a minimum of seven bytes, representing
+the message
+.Em size[4] ,
+.Em type[1] ,
+and
+.Em tag[2] .
+In most or all available protocol specifications, these fields are unsigned
+integers in little-endian order.
+The driver limits request and response size to 8192 bytes, and will fail larger
+writes with
+.Er EMSGSIZE .
+Applications should, in their initial
+.Sy version
+message,
+negotiate an
+.Em msize[4]
+value less than or equal to 8192 bytes.
+.Pp
+Reads are interruptible and will block waiting for a response to a request sent
+in a previous write.
+If insufficient buffer space is provided to the read call to receive the
+message, the call will fail with
+.Er EOVERFLOW
+and the message will remain available for a subsequent read.
+Messages are provided as-is to the application, including the
+.Em size[4] ,
+.Em type[1] ,
+and
+.Em tag[2] .
+.Pp
+Depending on the 9P server provided by the hypervisor, requests that are issued
+concurrently may result in responses that arrive out of order.
+Applications should develop a strategy for allocating unique
+.Em tag[2]
+values, so that request and response messages can be correlated.
+.Sh IOCTLS
+The driver provides an ioctl,
+.Dv VIO9P_IOC_MOUNT_TAG ,
+to expose the
+.Em Mount Tag
+string if one was provided by the hypervisor.
+The ioctl is defined in
+.In sys/vio9p.h .
+The argument must be a
+.Vt "char *" ,
+pointing to a buffer of
+.Dv VIO9P_MOUNT_TAG_SIZE
+bytes.
+On success, the buffer will contain the mount tag string as read from the
+hypervisor, followed by a null-terminating zero byte added by the driver to
+ensure the result can always be treated as a C string.
+While the hypervisor is expected to provide a human-readable C string,
+applications should take care to verify that the contents are valid for display
+or other purposes.
+Note that even if successfully read, the string may be empty.
+.Sh FILES
+.Bl -tag -width Pa
+.It Pa /dev/9p/*
+Character device for access to a 9P channel.
+.It Pa /kernel/drv/amd64/vio9p
+Device driver (x86)
+.El
+.Sh INTERFACE STABILITY
+.Sy Uncommitted
+.Sh SEE ALSO
+.Xr close 2 ,
+.Xr ioctl 2 ,
+.Xr open 2 ,
+.Xr read 2 ,
+.Xr write 2
diff --git a/usr/src/pkg/manifests/driver-storage-vio9p.p5m b/usr/src/pkg/manifests/driver-storage-vio9p.p5m
new file mode 100644
index 0000000000..f4ce42c1a6
--- /dev/null
+++ b/usr/src/pkg/manifests/driver-storage-vio9p.p5m
@@ -0,0 +1,40 @@
+#
+# CDDL HEADER START
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2022 Oxide Computer Company
+#
+
+#
+# The default for payload-bearing actions in this package is to appear in the
+# global zone only.  See the include file for greater detail, as well as
+# information about overriding the defaults.
+#
+<include global_zone_only_component>
+set name=pkg.fmri value=pkg:/driver/storage/vio9p@$(PKGVERS)
+set name=pkg.summary value="Virtio 9P transport driver"
+set name=pkg.description value="Virtio 9P transport driver"
+set name=info.classification value=org.opensolaris.category.2008:Drivers/Storage
+set name=variant.arch value=$(ARCH)
+dir  path=kernel group=sys
+dir  path=kernel/drv group=sys
+dir  path=kernel/drv/$(ARCH64) group=sys
+file path=kernel/drv/$(ARCH64)/vio9p group=sys
+file path=usr/include/sys/vio9p.h
+dir  path=usr/share/man
+dir  path=usr/share/man/man4d
+file path=usr/share/man/man4d/vio9p.4d
+driver name=vio9p perms="* 0600 root root" alias=pci1af4,9
+license lic_CDDL license=lic_CDDL
diff --git a/usr/src/uts/common/Makefile.files b/usr/src/uts/common/Makefile.files
index dc5503379f..26e20efb9c 100644
--- a/usr/src/uts/common/Makefile.files
+++ b/usr/src/uts/common/Makefile.files
@@ -2128,6 +2128,9 @@ VIOIF_OBJS = vioif.o
 # Virtio SCSI driver
 VIOSCSI_OBJS = vioscsi.o
 
+# Virtio 9P transport driver
+VIO9P_OBJS = vio9p.o
+
 #
 #	kiconv modules
 #
diff --git a/usr/src/uts/common/Makefile.rules b/usr/src/uts/common/Makefile.rules
index c8a6ce9d0c..8ef8c5eb9d 100644
--- a/usr/src/uts/common/Makefile.rules
+++ b/usr/src/uts/common/Makefile.rules
@@ -1557,6 +1557,10 @@ $(OBJS_DIR)/%.o:		$(UTSBASE)/common/io/vioscsi/%.c
 	$(COMPILE.c) -o $@ $<
 	$(CTFCONVERT_O)
 
+$(OBJS_DIR)/%.o:		$(UTSBASE)/common/io/vio9p/%.c
+	$(COMPILE.c) -o $@ $<
+	$(CTFCONVERT_O)
+
 $(OBJS_DIR)/%.o:		$(COMMONBASE)/idspace/%.c
 	$(COMPILE.c) -o $@ $<
 	$(CTFCONVERT_O)
diff --git a/usr/src/uts/common/dtrace/lockstat.c b/usr/src/uts/common/dtrace/lockstat.c
index 69c8b72544..08f819d453 100644
--- a/usr/src/uts/common/dtrace/lockstat.c
+++ b/usr/src/uts/common/dtrace/lockstat.c
@@ -21,6 +21,7 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2022 Oxide Computer Company
  */
 
 
@@ -93,7 +94,7 @@ lockstat_enable(void *arg, dtrace_id_t id, void *parg)
 	lockstat_probemap[probe->lsp_probe] = id;
 	membar_producer();
 
-	lockstat_hot_patch();
+	lockstat_hotpatch_probe(probe->lsp_probe);
 	membar_producer();
 
 	/*
@@ -115,7 +116,7 @@ lockstat_disable(void *arg, dtrace_id_t id, void *parg)
 	ASSERT(lockstat_probemap[probe->lsp_probe]);
 
 	lockstat_probemap[probe->lsp_probe] = 0;
-	lockstat_hot_patch();
+	lockstat_hotpatch_probe(probe->lsp_probe);
 	membar_producer();
 
 	/*
diff --git a/usr/src/uts/common/io/vio9p/vio9p.c b/usr/src/uts/common/io/vio9p/vio9p.c
new file mode 100644
index 0000000000..5302043365
--- /dev/null
+++ b/usr/src/uts/common/io/vio9p/vio9p.c
@@ -0,0 +1,839 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2022 Oxide Computer Company
+ */
+
+/*
+ * VIRTIO 9P DRIVER
+ *
+ * This driver provides support for Virtio 9P devices.  Each driver instance
+ * attaches to a single underlying 9P channel.  A 9P file system will use LDI
+ * to open this device.
+ */
+
+#include <sys/modctl.h>
+#include <sys/types.h>
+#include <sys/file.h>
+#include <sys/errno.h>
+#include <sys/param.h>
+#include <sys/stropts.h>
+#include <sys/stream.h>
+#include <sys/strsubr.h>
+#include <sys/kmem.h>
+#include <sys/ddi.h>
+#include <sys/sunddi.h>
+#include <sys/conf.h>
+#include <sys/devops.h>
+#include <sys/ksynch.h>
+#include <sys/stat.h>
+#include <sys/modctl.h>
+#include <sys/debug.h>
+#include <sys/pci.h>
+#include <sys/containerof.h>
+#include <sys/ctype.h>
+#include <sys/stdbool.h>
+#include <sys/sysmacros.h>
+#include <sys/list.h>
+
+#include "virtio.h"
+#include "vio9p_impl.h"
+
+static void *vio9p_state;
+
+uint_t vio9p_int_handler(caddr_t, caddr_t);
+static uint_t vio9p_poll(vio9p_t *);
+static int vio9p_quiesce(dev_info_t *);
+static int vio9p_attach(dev_info_t *, ddi_attach_cmd_t);
+static int vio9p_teardown(vio9p_t *, vio9p_teardown_style_t);
+static int vio9p_detach(dev_info_t *, ddi_detach_cmd_t);
+static int vio9p_open(dev_t *, int, int, cred_t *);
+static int vio9p_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);
+static int vio9p_close(dev_t, int, int, cred_t *);
+static int vio9p_read(dev_t, uio_t *, cred_t *);
+static int vio9p_write(dev_t, uio_t *, cred_t *);
+static vio9p_req_t *vio9p_req_alloc_impl(vio9p_t *, int);
+static void vio9p_req_free_impl(vio9p_t *, vio9p_req_t *);
+
+static struct cb_ops vio9p_cb_ops = {
+	.cb_rev =			CB_REV,
+	.cb_flag =			D_NEW | D_MP,
+
+	.cb_open =			vio9p_open,
+	.cb_close =			vio9p_close,
+	.cb_read =			vio9p_read,
+	.cb_write =			vio9p_write,
+	.cb_ioctl =			vio9p_ioctl,
+
+	.cb_strategy =			nodev,
+	.cb_print =			nodev,
+	.cb_dump =			nodev,
+	.cb_devmap =			nodev,
+	.cb_mmap =			nodev,
+	.cb_segmap =			nodev,
+	.cb_chpoll =			nochpoll,
+	.cb_prop_op =			ddi_prop_op,
+	.cb_str =			NULL,
+	.cb_aread =			nodev,
+	.cb_awrite =			nodev,
+};
+
+static struct dev_ops vio9p_dev_ops = {
+	.devo_rev =			DEVO_REV,
+	.devo_refcnt =			0,
+
+	.devo_attach =			vio9p_attach,
+	.devo_detach =			vio9p_detach,
+	.devo_quiesce =			vio9p_quiesce,
+
+	.devo_cb_ops =			&vio9p_cb_ops,
+
+	.devo_getinfo =			ddi_no_info,
+	.devo_identify =		nulldev,
+	.devo_probe =			nulldev,
+	.devo_reset =			nodev,
+	.devo_bus_ops =			NULL,
+	.devo_power =			NULL,
+};
+
+static struct modldrv vio9p_modldrv = {
+	.drv_modops =			&mod_driverops,
+	.drv_linkinfo =			"VIRTIO 9P driver",
+	.drv_dev_ops =			&vio9p_dev_ops
+};
+
+static struct modlinkage vio9p_modlinkage = {
+	.ml_rev =			MODREV_1,
+	.ml_linkage =			{ &vio9p_modldrv, NULL }
+};
+
+/*
+ * DMA attribute template for header and status blocks.
+ */
+static const ddi_dma_attr_t vio9p_dma_attr = {
+	.dma_attr_version =		DMA_ATTR_V0,
+	.dma_attr_addr_lo =		0x0000000000000000,
+	.dma_attr_addr_hi =		0xFFFFFFFFFFFFFFFF,
+	.dma_attr_count_max =		0x00000000FFFFFFFF,
+	.dma_attr_align =		1,
+	.dma_attr_burstsizes =		1,
+	.dma_attr_minxfer =		1,
+	.dma_attr_maxxfer =		0x00000000FFFFFFFF,
+	.dma_attr_seg =			0x00000000FFFFFFFF,
+	.dma_attr_sgllen =		VIRTIO_9P_MAX_SGL,
+	.dma_attr_granular =		1,
+	.dma_attr_flags =		0
+};
+
+uint_t
+vio9p_int_handler(caddr_t arg0, caddr_t arg1)
+{
+	vio9p_t *vin = (vio9p_t *)arg0;
+
+	mutex_enter(&vin->vin_mutex);
+	uint_t count = vio9p_poll(vin);
+	mutex_exit(&vin->vin_mutex);
+
+	return (count > 0 ? DDI_INTR_CLAIMED : DDI_INTR_UNCLAIMED);
+}
+
+static void
+vio9p_req_freelist_put(vio9p_t *vin, vio9p_req_t *vnr)
+{
+	VERIFY(!list_link_active(&vnr->vnr_link_complete));
+	VERIFY(!list_link_active(&vnr->vnr_link_free));
+
+	vin->vin_generation = 0;
+	list_insert_head(&vin->vin_req_freelist, vnr);
+
+	if (vin->vin_open) {
+		/*
+		 * Wake any callers waiting in vio9p_req_alloc() for an entry:
+		 */
+		cv_broadcast(&vin->vin_cv);
+	}
+}
+
+static void
+vio9p_req_free(vio9p_t *vin, vio9p_req_t *vnr)
+{
+	VERIFY(MUTEX_HELD(&vin->vin_mutex));
+
+	if (list_link_active(&vnr->vnr_link_complete)) {
+		list_remove(&vin->vin_completes, vnr);
+	}
+
+	vio9p_req_freelist_put(vin, vnr);
+}
+
+static void
+vio9p_req_free_impl(vio9p_t *vin, vio9p_req_t *vnr)
+{
+	if (vnr->vnr_chain != NULL) {
+		virtio_chain_free(vnr->vnr_chain);
+		vnr->vnr_chain = NULL;
+	}
+	if (vnr->vnr_dma_in != NULL) {
+		virtio_dma_free(vnr->vnr_dma_in);
+		vnr->vnr_dma_in = NULL;
+	}
+	if (vnr->vnr_dma_out != NULL) {
+		virtio_dma_free(vnr->vnr_dma_out);
+		vnr->vnr_dma_out = NULL;
+	}
+
+	VERIFY(!list_link_active(&vnr->vnr_link_complete));
+	VERIFY(!list_link_active(&vnr->vnr_link_free));
+
+	list_remove(&vin->vin_reqs, vnr);
+	VERIFY3U(vin->vin_nreqs, >, 0);
+	vin->vin_nreqs--;
+
+	kmem_free(vnr, sizeof (*vnr));
+}
+
+/*
+ * Allocate a request for a transaction.  If one is not available and this is
+ * for a blocking request, wait for one to become available.
+ */
+static vio9p_req_t *
+vio9p_req_alloc(vio9p_t *vin, bool wait)
+{
+	vio9p_req_t *vnr;
+
+	VERIFY(MUTEX_HELD(&vin->vin_mutex));
+
+again:
+	/*
+	 * Try the free list first:
+	 */
+	if ((vnr = list_remove_head(&vin->vin_req_freelist)) != NULL) {
+		return (vnr);
+	}
+
+	/*
+	 * Failing that, try to allocate more memory if we are under our
+	 * request cap:
+	 */
+	if ((vnr = vio9p_req_alloc_impl(vin, KM_NOSLEEP_LAZY)) != NULL) {
+		return (vnr);
+	}
+
+	/*
+	 * If this is a blocking request, wait for an entry to become available
+	 * on the free list:
+	 */
+	if (wait) {
+		if (cv_wait_sig(&vin->vin_cv, &vin->vin_mutex) == 0) {
+			return (NULL);
+		}
+
+		goto again;
+	}
+
+	return (NULL);
+}
+
+static vio9p_req_t *
+vio9p_req_alloc_impl(vio9p_t *vin, int kmflag)
+{
+	dev_info_t *dip = vin->vin_dip;
+	vio9p_req_t *vnr;
+
+	if (vin->vin_nreqs >= VIRTIO_9P_MAX_REQS) {
+		/*
+		 * We have reached the limit of requests that we are willing to
+		 * allocate for the whole device.
+		 */
+		return (NULL);
+	}
+
+	/*
+	 * Note that the request object has various list link fields which are
+	 * initialised to zero here and which we check at various points later.
+	 */
+	if ((vnr = kmem_zalloc(sizeof (*vnr), kmflag)) == NULL) {
+		return (NULL);
+	}
+	list_insert_tail(&vin->vin_reqs, vnr);
+	vin->vin_nreqs++;
+
+	if ((vnr->vnr_chain = virtio_chain_alloc(vin->vin_vq, kmflag)) ==
+	    NULL) {
+		dev_err(vin->vin_dip, CE_WARN, "!chain alloc failure");
+		goto fail;
+	}
+	virtio_chain_data_set(vnr->vnr_chain, vnr);
+
+	/*
+	 * Allocate outbound request buffer:
+	 */
+	if ((vnr->vnr_dma_out = virtio_dma_alloc(vin->vin_virtio,
+	    VIRTIO_9P_REQ_SIZE, &vio9p_dma_attr,
+	    DDI_DMA_CONSISTENT | DDI_DMA_WRITE, kmflag)) == NULL) {
+		dev_err(dip, CE_WARN, "!DMA out alloc failure");
+		goto fail;
+	}
+	VERIFY3U(virtio_dma_ncookies(vnr->vnr_dma_out), <=, VIRTIO_9P_MAX_SGL);
+
+	for (uint_t n = 0; n < virtio_dma_ncookies(vnr->vnr_dma_out); n++) {
+		if (virtio_chain_append(vnr->vnr_chain,
+		    virtio_dma_cookie_pa(vnr->vnr_dma_out, n),
+		    virtio_dma_cookie_size(vnr->vnr_dma_out, n),
+		    VIRTIO_DIR_DEVICE_READS) != DDI_SUCCESS) {
+			dev_err(dip, CE_WARN, "!chain append out failure");
+			goto fail;
+		}
+	}
+
+	/*
+	 * Allocate inbound request buffer:
+	 */
+	if ((vnr->vnr_dma_in = virtio_dma_alloc(vin->vin_virtio,
+	    VIRTIO_9P_REQ_SIZE, &vio9p_dma_attr,
+	    DDI_DMA_CONSISTENT | DDI_DMA_READ, kmflag)) == NULL) {
+		dev_err(dip, CE_WARN, "!DMA in alloc failure");
+		goto fail;
+	}
+	VERIFY3U(virtio_dma_ncookies(vnr->vnr_dma_in), <=, VIRTIO_9P_MAX_SGL);
+
+	for (uint_t n = 0; n < virtio_dma_ncookies(vnr->vnr_dma_in); n++) {
+		if (virtio_chain_append(vnr->vnr_chain,
+		    virtio_dma_cookie_pa(vnr->vnr_dma_in, n),
+		    virtio_dma_cookie_size(vnr->vnr_dma_in, n),
+		    VIRTIO_DIR_DEVICE_WRITES) != DDI_SUCCESS) {
+			dev_err(dip, CE_WARN, "!chain append in failure");
+			goto fail;
+		}
+	}
+
+	return (vnr);
+
+fail:
+	vio9p_req_free_impl(vin, vnr);
+	return (NULL);
+}
+
+static uint_t
+vio9p_poll(vio9p_t *vin)
+{
+	virtio_chain_t *vic;
+	uint_t count = 0;
+	bool wakeup = false;
+
+	VERIFY(MUTEX_HELD(&vin->vin_mutex));
+
+	while ((vic = virtio_queue_poll(vin->vin_vq)) != NULL) {
+		vio9p_req_t *vnr = virtio_chain_data(vic);
+
+		count++;
+
+		virtio_dma_sync(vnr->vnr_dma_in, DDI_DMA_SYNC_FORCPU);
+
+		if (!vin->vin_open ||
+		    vnr->vnr_generation != vin->vin_generation) {
+			/*
+			 * Either the device is not open, or the device has
+			 * been closed and opened again since this request was
+			 * submitted.  Just free the memory and drive on.
+			 */
+			vio9p_req_free(vin, vnr);
+			continue;
+		}
+
+		list_insert_tail(&vin->vin_completes, vnr);
+		wakeup = true;
+	}
+
+	if (wakeup) {
+		cv_broadcast(&vin->vin_cv);
+	}
+
+	return (count);
+}
+
+static int
+vio9p_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
+{
+	int instance = ddi_get_instance(dip);
+	virtio_t *vio;
+	vio9p_req_t *vnr;
+
+	if (cmd != DDI_ATTACH) {
+		return (DDI_FAILURE);
+	}
+
+	if (ddi_soft_state_zalloc(vio9p_state, instance) != DDI_SUCCESS) {
+		return (DDI_FAILURE);
+	}
+
+	if ((vio = virtio_init(dip, VIRTIO_9P_WANTED_FEATURES, B_TRUE)) ==
+	    NULL) {
+		ddi_soft_state_free(vio9p_state, instance);
+		dev_err(dip, CE_WARN, "failed to start Virtio init");
+		return (DDI_FAILURE);
+	}
+
+	vio9p_t *vin = ddi_get_soft_state(vio9p_state, instance);
+	vin->vin_dip = dip;
+	vin->vin_virtio = vio;
+	ddi_set_driver_private(dip, vin);
+	list_create(&vin->vin_reqs, sizeof (vio9p_req_t),
+	    offsetof(vio9p_req_t, vnr_link));
+	list_create(&vin->vin_completes, sizeof (vio9p_req_t),
+	    offsetof(vio9p_req_t, vnr_link_complete));
+	list_create(&vin->vin_req_freelist, sizeof (vio9p_req_t),
+	    offsetof(vio9p_req_t, vnr_link_free));
+
+	if (virtio_feature_present(vio, VIRTIO_9P_F_MOUNT_TAG)) {
+		uint16_t len = virtio_dev_get16(vio, VIRTIO_9P_CONFIG_TAG_SZ);
+		if (len > VIRTIO_9P_TAGLEN) {
+			len = VIRTIO_9P_TAGLEN;
+		}
+
+		/*
+		 * This array is one byte longer than VIRTIO_9P_TAGLEN, and is
+		 * thus always NUL-terminated by the use of
+		 * ddi_soft_state_zalloc() above.
+		 */
+		for (uint16_t n = 0; n < len; n++) {
+			vin->vin_tag[n] = virtio_dev_get8(vio,
+			    VIRTIO_9P_CONFIG_TAG + n);
+		}
+	}
+
+	/*
+	 * When allocating the request queue, we include enough slots for a
+	 * full set of cookies (based on our DMA attributes) in both the in and
+	 * the out direction.
+	 */
+	if ((vin->vin_vq = virtio_queue_alloc(vio, VIRTIO_9P_VIRTQ_REQUESTS,
+	    "requests", vio9p_int_handler, vin, B_FALSE,
+	    2 * VIRTIO_9P_MAX_SGL)) == NULL) {
+		return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_PRE_MUTEX));
+	}
+
+	if (virtio_init_complete(vio, VIRTIO_ANY_INTR_TYPE) != DDI_SUCCESS) {
+		dev_err(dip, CE_WARN, "failed to complete Virtio init");
+		return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_PRE_MUTEX));
+	}
+
+	cv_init(&vin->vin_cv, NULL, CV_DRIVER, NULL);
+	mutex_init(&vin->vin_mutex, NULL, MUTEX_DRIVER, virtio_intr_pri(vio));
+
+	/*
+	 * Make sure the free list contains at least one request at attach time
+	 * so that the device is always somewhat useable:
+	 */
+	if ((vnr = vio9p_req_alloc_impl(vin, KM_SLEEP)) == NULL) {
+		dev_err(dip, CE_WARN, "failed to allocate first request");
+		return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_ATTACH));
+	}
+	vio9p_req_freelist_put(vin, vnr);
+
+	if (virtio_interrupts_enable(vio) != DDI_SUCCESS) {
+		return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_ATTACH));
+	}
+
+	/*
+	 * Hang out a minor node so that we can be opened.
+	 */
+	int minor = ddi_get_instance(dip);
+	if (ddi_create_minor_node(dip, "9p", S_IFCHR, minor, DDI_PSEUDO,
+	    0) != DDI_SUCCESS) {
+		dev_err(dip, CE_WARN, "could not create minor node");
+		return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_ATTACH));
+	}
+
+	ddi_report_dev(dip);
+
+	return (DDI_SUCCESS);
+}
+
+static int
+vio9p_teardown(vio9p_t *vin, vio9p_teardown_style_t style)
+{
+	dev_info_t *dip = vin->vin_dip;
+
+	if (style != VIRTIO_9P_TEARDOWN_PRE_MUTEX) {
+		/*
+		 * Make sure we do not hold the mutex across interrupt disable.
+		 */
+		VERIFY(MUTEX_NOT_HELD(&vin->vin_mutex));
+	}
+
+	ddi_remove_minor_node(dip, NULL);
+
+	if (vin->vin_virtio != NULL) {
+		/*
+		 * Disable interrupts so that we can be sure our handler does
+		 * not run again while we free things.
+		 */
+		virtio_interrupts_disable(vin->vin_virtio);
+	}
+
+	/*
+	 * Empty the free list:
+	 */
+	for (;;) {
+		vio9p_req_t *vnr = list_remove_head(&vin->vin_req_freelist);
+		if (vnr == NULL) {
+			break;
+		}
+		vio9p_req_free_impl(vin, vnr);
+	}
+	VERIFY(list_is_empty(&vin->vin_req_freelist));
+	list_destroy(&vin->vin_req_freelist);
+
+	/*
+	 * Any active requests should have been freed in vio9p_detach(), so
+	 * there should be no other requests left at this point.
+	 */
+	VERIFY0(vin->vin_nreqs);
+	VERIFY(list_is_empty(&vin->vin_reqs));
+	list_destroy(&vin->vin_reqs);
+
+	VERIFY(list_is_empty(&vin->vin_completes));
+	list_destroy(&vin->vin_completes);
+
+	/*
+	 * Tear down the Virtio framework.
+	 */
+	if (vin->vin_virtio != NULL) {
+		boolean_t failed = (style != VIRTIO_9P_TEARDOWN_DETACH);
+		virtio_fini(vin->vin_virtio, failed);
+	}
+
+	if (style != VIRTIO_9P_TEARDOWN_PRE_MUTEX) {
+		mutex_destroy(&vin->vin_mutex);
+		cv_destroy(&vin->vin_cv);
+	}
+
+	ddi_set_driver_private(dip, NULL);
+	ddi_soft_state_free(vio9p_state, ddi_get_instance(dip));
+
+	return (style == VIRTIO_9P_TEARDOWN_DETACH ? DDI_SUCCESS : DDI_FAILURE);
+}
+
+static int
+vio9p_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
+{
+	vio9p_t *vin = ddi_get_driver_private(dip);
+
+	if (cmd != DDI_DETACH) {
+		return (DDI_FAILURE);
+	}
+
+	mutex_enter(&vin->vin_mutex);
+
+	/*
+	 * Detach will only be called once we are no longer held open.
+	 */
+	VERIFY(!vin->vin_open);
+
+	/*
+	 * If a request was submitted to the hypervisor but never completed, it
+	 * may still be active even though the device has been closed.
+	 */
+	bool shutdown = false;
+	for (vio9p_req_t *vnr = list_head(&vin->vin_reqs);
+	    vnr != NULL; vnr = list_next(&vin->vin_reqs, vnr)) {
+		if (!list_link_active(&vnr->vnr_link_free)) {
+			/*
+			 * There is at least one active request.  We need to
+			 * reset the device to claw back the DMA memory.
+			 */
+			shutdown = true;
+			break;
+		}
+	}
+
+	if (shutdown) {
+		virtio_chain_t *vic;
+
+		virtio_shutdown(vin->vin_virtio);
+		while ((vic = virtio_queue_evacuate(vin->vin_vq)) != NULL) {
+			vio9p_req_t *vnr = virtio_chain_data(vic);
+
+			virtio_dma_sync(vnr->vnr_dma_in, DDI_DMA_SYNC_FORCPU);
+
+			vio9p_req_free_impl(vin, vnr);
+		}
+	}
+
+	mutex_exit(&vin->vin_mutex);
+
+	return (vio9p_teardown(vin, VIRTIO_9P_TEARDOWN_DETACH));
+}
+
+static int
+vio9p_quiesce(dev_info_t *dip)
+{
+	vio9p_t *vin;
+
+	if ((vin = ddi_get_driver_private(dip)) == NULL) {
+		return (DDI_FAILURE);
+	}
+
+	return (virtio_quiesce(vin->vin_virtio));
+}
+
+static int
+vio9p_open(dev_t *dev, int flag, int otyp, cred_t *cred)
+{
+	if (otyp != OTYP_CHR) {
+		return (EINVAL);
+	}
+
+	/*
+	 * This device represents a request-response communication channel
+	 * between the host and the hypervisor; as such we insist that it be
+	 * opened exclusively, and for both read and write access.
+	 */
+	if (!(flag & FEXCL) || !(flag & FREAD) || !(flag & FWRITE)) {
+		return (EINVAL);
+	}
+
+	vio9p_t *vin = ddi_get_soft_state(vio9p_state, getminor(*dev));
+	if (vin == NULL) {
+		return (ENXIO);
+	}
+
+	mutex_enter(&vin->vin_mutex);
+	if (vin->vin_open) {
+		mutex_exit(&vin->vin_mutex);
+		return (EBUSY);
+	}
+	vin->vin_open = true;
+
+	vin->vin_generation++;
+	if (vin->vin_generation == 0) {
+		vin->vin_generation++;
+	}
+
+	mutex_exit(&vin->vin_mutex);
+	return (0);
+}
+
+static int
+vio9p_close(dev_t dev, int flag, int otyp, cred_t *cred)
+{
+	if (otyp != OTYP_CHR) {
+		return (EINVAL);
+	}
+
+	vio9p_t *vin = ddi_get_soft_state(vio9p_state, getminor(dev));
+	if (vin == NULL) {
+		return (ENXIO);
+	}
+
+	mutex_enter(&vin->vin_mutex);
+	if (!vin->vin_open) {
+		mutex_exit(&vin->vin_mutex);
+		return (EIO);
+	}
+
+	/*
+	 * Free all completed requests that have not yet been read:
+	 */
+	vio9p_req_t *vnr;
+	while ((vnr = list_remove_head(&vin->vin_completes)) != NULL) {
+		vio9p_req_free(vin, vnr);
+	}
+
+	vin->vin_open = false;
+	mutex_exit(&vin->vin_mutex);
+	return (0);
+}
+
+static int
+vio9p_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cred,
+    int *rvalp)
+{
+	vio9p_t *vin = ddi_get_soft_state(vio9p_state, getminor(dev));
+	if (vin == NULL) {
+		return (ENXIO);
+	}
+
+	switch (cmd) {
+	case VIO9P_IOC_MOUNT_TAG:
+		if (ddi_copyout(vin->vin_tag, (void *)arg,
+		    sizeof (vin->vin_tag), mode) != 0) {
+			return (EFAULT);
+		}
+		return (0);
+
+	default:
+		return (ENOTTY);
+	}
+}
+
+static int
+vio9p_read(dev_t dev, struct uio *uio, cred_t *cred)
+{
+	bool blocking = (uio->uio_fmode & (FNDELAY | FNONBLOCK)) == 0;
+	vio9p_req_t *vnr;
+	vio9p_t *vin;
+
+	if ((vin = ddi_get_soft_state(vio9p_state, getminor(dev))) == NULL) {
+		return (ENXIO);
+	}
+
+	mutex_enter(&vin->vin_mutex);
+again:
+	if ((vnr = list_remove_head(&vin->vin_completes)) == NULL) {
+		if (!blocking) {
+			mutex_exit(&vin->vin_mutex);
+			return (EAGAIN);
+		}
+
+		/*
+		 * There is nothing to read right now.  Wait for something:
+		 */
+		if (cv_wait_sig(&vin->vin_cv, &vin->vin_mutex) == 0) {
+			mutex_exit(&vin->vin_mutex);
+			return (EINTR);
+		}
+		goto again;
+	}
+
+	/*
+	 * Determine the size of the response message using the initial size[4]
+	 * field of the response.  The various specifying documents that exist
+	 * suggest this is an unsigned integer in little-endian order.
+	 */
+	uint32_t msz;
+	bcopy(virtio_dma_va(vnr->vnr_dma_in, 0), &msz, sizeof (msz));
+	msz = LE_32(msz);
+	if (msz > virtio_dma_size(vnr->vnr_dma_in)) {
+		msz = virtio_dma_size(vnr->vnr_dma_in);
+	}
+
+	if (msz > uio->uio_resid) {
+		/*
+		 * Tell the consumer they are going to need a bigger
+		 * buffer.
+		 */
+		list_insert_head(&vin->vin_completes, vnr);
+		mutex_exit(&vin->vin_mutex);
+		return (EOVERFLOW);
+	}
+
+	mutex_exit(&vin->vin_mutex);
+	int e = uiomove(virtio_dma_va(vnr->vnr_dma_in, 0), msz, UIO_READ, uio);
+	mutex_enter(&vin->vin_mutex);
+
+	if (e == 0) {
+		vio9p_req_free(vin, vnr);
+	} else {
+		/*
+		 * Put the response back in the list for another try, so that
+		 * we do not drop any messages:
+		 */
+		list_insert_head(&vin->vin_completes, vnr);
+	}
+
+	mutex_exit(&vin->vin_mutex);
+	return (e);
+}
+
+static int
+vio9p_write(dev_t dev, struct uio *uio, cred_t *cred)
+{
+	bool blocking = (uio->uio_fmode & (FNDELAY | FNONBLOCK)) == 0;
+
+	size_t wsz = uio->uio_resid;
+	if (wsz < 7) {
+		/*
+		 * Requests should be well-formed 9P messages.  They must
+		 * contain at least 7 bytes: msize[4] + type[1] + tag[2].
+		 */
+		return (EINVAL);
+	} else if (wsz > VIRTIO_9P_REQ_SIZE) {
+		return (EMSGSIZE);
+	}
+
+	vio9p_t *vin = ddi_get_soft_state(vio9p_state, getminor(dev));
+	if (vin == NULL) {
+		return (ENXIO);
+	}
+
+	mutex_enter(&vin->vin_mutex);
+	vio9p_req_t *vnr = vio9p_req_alloc(vin, blocking);
+	if (vnr == NULL) {
+		mutex_exit(&vin->vin_mutex);
+		return (blocking ? ENOMEM : EAGAIN);
+	}
+	vnr->vnr_generation = vin->vin_generation;
+	VERIFY3U(wsz, <=, virtio_dma_size(vnr->vnr_dma_out));
+
+	mutex_exit(&vin->vin_mutex);
+	int e = uiomove(virtio_dma_va(vnr->vnr_dma_out, 0), wsz, UIO_WRITE,
+	    uio);
+	mutex_enter(&vin->vin_mutex);
+
+	if (e == 0) {
+		virtio_dma_sync(vnr->vnr_dma_out, DDI_DMA_SYNC_FORDEV);
+		virtio_chain_submit(vnr->vnr_chain, B_TRUE);
+	} else {
+		vio9p_req_free(vin, vnr);
+	}
+
+	mutex_exit(&vin->vin_mutex);
+	return (e);
+}
+
+int
+_init(void)
+{
+	int r;
+
+	if ((r = ddi_soft_state_init(&vio9p_state, sizeof (vio9p_t), 0)) != 0) {
+		return (r);
+	}
+
+	if ((r = mod_install(&vio9p_modlinkage)) != 0) {
+		ddi_soft_state_fini(&vio9p_state);
+	}
+
+	return (r);
+}
+
+int
+_fini(void)
+{
+	int r;
+
+	if ((r = mod_remove(&vio9p_modlinkage)) != 0) {
+		return (r);
+	}
+
+	ddi_soft_state_fini(&vio9p_state);
+
+	return (r);
+}
+
+int
+_info(struct modinfo *modinfop)
+{
+	return (mod_info(&vio9p_modlinkage, modinfop));
+}
diff --git a/usr/src/uts/common/io/vio9p/vio9p_impl.h b/usr/src/uts/common/io/vio9p/vio9p_impl.h
new file mode 100644
index 0000000000..f8718c1ed2
--- /dev/null
+++ b/usr/src/uts/common/io/vio9p/vio9p_impl.h
@@ -0,0 +1,126 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2022 Oxide Computer Company
+ */
+
+/*
+ * VIRTIO 9P DRIVER
+ */
+
+#ifndef _VIO9P_IMPL_H
+#define	_VIO9P_IMPL_H
+
+#include "virtio.h"
+#include <sys/vio9p.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * VIRTIO 9P CONFIGURATION REGISTERS
+ *
+ * These are offsets into the device-specific configuration space available
+ * through the virtio_dev_*() family of functions.
+ */
+#define	VIRTIO_9P_CONFIG_TAG_SZ			0x00	/* 16 R   */
+#define	VIRTIO_9P_CONFIG_TAG			0x02	/* SZ R   */
+
+/*
+ * VIRTIO 9P VIRTQUEUES
+ *
+ * Virtio 9P devices have just one queue which is used to make 9P requests.
+ * Each submitted chain should include appropriately sized inbound and outbound
+ * descriptors for the request and response messages.  The maximum size is
+ * negotiated via the "msize" member of the 9P TVERSION request and RVERSION
+ * response.  Some hypervisors may require the first 7 bytes (size, type, tag)
+ * to be contiguous in the first descriptor.
+ */
+#define	VIRTIO_9P_VIRTQ_REQUESTS	0
+
+/*
+ * VIRTIO 9P FEATURE BITS
+ */
+#define	VIRTIO_9P_F_MOUNT_TAG		(1ULL << 0)
+
+/*
+ * These features are supported by the driver and we will request them from the
+ * device.
+ */
+#define	VIRTIO_9P_WANTED_FEATURES	(VIRTIO_9P_F_MOUNT_TAG)
+
+/*
+ * DRIVER PARAMETERS
+ */
+#define	VIRTIO_9P_MAX_REQS		16
+#define	VIRTIO_9P_REQ_SIZE		8192
+
+/*
+ * It is not clear that there is a well-defined number of cookies for this
+ * interface; QEMU may support as many as there are direct descriptors in the
+ * ring, and bhyve may support something like 128.  We'll use a conservative
+ * number that's large enough to ensure we'll be able to allocate without
+ * requiring contiguous pages.
+ */
+#define	VIRTIO_9P_MAX_SGL		8
+
+/*
+ * TYPE DEFINITIONS
+ */
+
+typedef enum vio9p_teardown_style {
+	VIRTIO_9P_TEARDOWN_PRE_MUTEX,
+	VIRTIO_9P_TEARDOWN_ATTACH,
+	VIRTIO_9P_TEARDOWN_DETACH,
+} vio9p_teardown_style_t;
+
+typedef struct vio9p_req {
+	virtio_dma_t			*vnr_dma_in;
+	virtio_dma_t			*vnr_dma_out;
+	virtio_chain_t			*vnr_chain;
+	list_node_t			vnr_link;
+	list_node_t			vnr_link_complete;
+	list_node_t			vnr_link_free;
+	uint64_t			vnr_generation;
+} vio9p_req_t;
+
+typedef struct vio9p {
+	dev_info_t			*vin_dip;
+	virtio_t			*vin_virtio;
+	virtio_queue_t			*vin_vq;
+
+	kmutex_t			vin_mutex;
+	kcondvar_t			vin_cv;
+
+	/*
+	 * When the device is opened, select a generation number.  This will be
+	 * used to discard completed responses that arrive after the device was
+	 * closed and reopened.
+	 */
+	uint64_t			vin_generation;
+	bool				vin_open;
+
+	uint_t				vin_nreqs;
+	list_t				vin_reqs;
+	list_t				vin_completes;
+
+	list_t				vin_req_freelist;
+
+	char				vin_tag[VIO9P_MOUNT_TAG_SIZE];
+} vio9p_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _VIO9P_IMPL_H */
diff --git a/usr/src/uts/common/io/vioblk/vioblk.c b/usr/src/uts/common/io/vioblk/vioblk.c
index f6649bdd12..1c00d67184 100644
--- a/usr/src/uts/common/io/vioblk/vioblk.c
+++ b/usr/src/uts/common/io/vioblk/vioblk.c
@@ -981,7 +981,7 @@ vioblk_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
 
 	virtio_register_cfgchange_handler(vio, vioblk_cfgchange, vib);
 
-	if (virtio_init_complete(vio, 0) != DDI_SUCCESS) {
+	if (virtio_init_complete(vio, VIRTIO_ANY_INTR_TYPE) != DDI_SUCCESS) {
 		dev_err(dip, CE_WARN, "failed to complete Virtio init");
 		goto fail;
 	}
diff --git a/usr/src/uts/common/io/vioif/vioif.c b/usr/src/uts/common/io/vioif/vioif.c
index ae1e2d4ee2..74f1d46a69 100644
--- a/usr/src/uts/common/io/vioif/vioif.c
+++ b/usr/src/uts/common/io/vioif/vioif.c
@@ -1916,7 +1916,7 @@ vioif_select_interrupt_types(void)
 		 * The system may not have valid SMBIOS data, so ignore a
 		 * failure here.
 		 */
-		return (0);
+		return (VIRTIO_ANY_INTR_TYPE);
 	}
 
 	if (strcmp(info.smbi_manufacturer, "Google") == 0 &&
@@ -1931,7 +1931,7 @@ vioif_select_interrupt_types(void)
 		return (DDI_INTR_TYPE_FIXED);
 	}
 
-	return (0);
+	return (VIRTIO_ANY_INTR_TYPE);
 }
 
 static int
diff --git a/usr/src/uts/common/io/vioscsi/vioscsi.c b/usr/src/uts/common/io/vioscsi/vioscsi.c
index 0c83b33489..6d3d1e374a 100644
--- a/usr/src/uts/common/io/vioscsi/vioscsi.c
+++ b/usr/src/uts/common/io/vioscsi/vioscsi.c
@@ -1263,7 +1263,7 @@ vioscsi_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
 		return (DDI_FAILURE);
 	}
 
-	if (virtio_init_complete(vio, 0) != DDI_SUCCESS) {
+	if (virtio_init_complete(vio, VIRTIO_ANY_INTR_TYPE) != DDI_SUCCESS) {
 		dev_err(dip, CE_WARN, "virtio_init_complete failed");
 		vioscsi_teardown(sc, B_TRUE);
 		return (DDI_FAILURE);
diff --git a/usr/src/uts/common/io/virtio/virtio.h b/usr/src/uts/common/io/virtio/virtio.h
index 48e15b28f2..820bc3b811 100644
--- a/usr/src/uts/common/io/virtio/virtio.h
+++ b/usr/src/uts/common/io/virtio/virtio.h
@@ -350,6 +350,12 @@ uint_t virtio_dma_ncookies(virtio_dma_t *);
 uint64_t virtio_dma_cookie_pa(virtio_dma_t *, uint_t);
 size_t virtio_dma_cookie_size(virtio_dma_t *, uint_t);
 
+/*
+ * virtio_init_complete() accepts a mask of allowed interrupt types using the
+ * DDI_INTR_TYPE_* family of constants.  If no specific interrupt type is
+ * required, pass VIRTIO_ANY_INTR_TYPE instead:
+ */
+#define	VIRTIO_ANY_INTR_TYPE	0
 
 #ifdef __cplusplus
 }
diff --git a/usr/src/uts/common/io/virtio/virtio_dma.c b/usr/src/uts/common/io/virtio/virtio_dma.c
index 81972b5402..b2cbbb2acf 100644
--- a/usr/src/uts/common/io/virtio/virtio_dma.c
+++ b/usr/src/uts/common/io/virtio/virtio_dma.c
@@ -11,6 +11,7 @@
 
 /*
  * Copyright 2019 Joyent, Inc.
+ * Copyright 2022 Oxide Computer Company
  */
 
 /*
@@ -40,7 +41,21 @@
 #include "virtio.h"
 #include "virtio_impl.h"
 
+typedef int (dma_wait_t)(caddr_t);
 
+static dma_wait_t *
+virtio_dma_wait_from_kmflags(int kmflags)
+{
+	switch (kmflags) {
+	case KM_SLEEP:
+		return (DDI_DMA_SLEEP);
+	case KM_NOSLEEP:
+	case KM_NOSLEEP_LAZY:
+		return (DDI_DMA_DONTWAIT);
+	default:
+		panic("unexpected kmflags value 0x%x", kmflags);
+	}
+}
 
 void
 virtio_dma_sync(virtio_dma_t *vidma, int flag)
@@ -90,10 +105,7 @@ virtio_dma_init_handle(virtio_t *vio, virtio_dma_t *vidma,
 {
 	int r;
 	dev_info_t *dip = vio->vio_dip;
-
-	VERIFY(kmflags == KM_SLEEP || kmflags == KM_NOSLEEP);
-	int (*dma_wait)(caddr_t) = (kmflags == KM_SLEEP) ? DDI_DMA_SLEEP :
-	    DDI_DMA_DONTWAIT;
+	int (*dma_wait)(caddr_t) = virtio_dma_wait_from_kmflags(kmflags);
 
 	vidma->vidma_virtio = vio;
 
@@ -124,10 +136,7 @@ virtio_dma_init(virtio_t *vio, virtio_dma_t *vidma, size_t sz,
 	int r;
 	dev_info_t *dip = vio->vio_dip;
 	caddr_t va = NULL;
-
-	VERIFY(kmflags == KM_SLEEP || kmflags == KM_NOSLEEP);
-	int (*dma_wait)(caddr_t) = (kmflags == KM_SLEEP) ? DDI_DMA_SLEEP :
-	    DDI_DMA_DONTWAIT;
+	int (*dma_wait)(caddr_t) = virtio_dma_wait_from_kmflags(kmflags);
 
 	if (virtio_dma_init_handle(vio, vidma, attr, kmflags) !=
 	    DDI_SUCCESS) {
@@ -168,10 +177,7 @@ virtio_dma_bind(virtio_dma_t *vidma, void *va, size_t sz, int dmaflags,
 	int r;
 	dev_info_t *dip = vidma->vidma_virtio->vio_dip;
 	ddi_dma_cookie_t dmac;
-
-	VERIFY(kmflags == KM_SLEEP || kmflags == KM_NOSLEEP);
-	int (*dma_wait)(caddr_t) = (kmflags == KM_SLEEP) ? DDI_DMA_SLEEP :
-	    DDI_DMA_DONTWAIT;
+	int (*dma_wait)(caddr_t) = virtio_dma_wait_from_kmflags(kmflags);
 
 	VERIFY(vidma->vidma_level & VIRTIO_DMALEVEL_HANDLE_ALLOC);
 	VERIFY(!(vidma->vidma_level & VIRTIO_DMALEVEL_HANDLE_BOUND));
diff --git a/usr/src/uts/common/io/virtio/virtio_main.c b/usr/src/uts/common/io/virtio/virtio_main.c
index 28dce6dc92..ec8bcd9f22 100644
--- a/usr/src/uts/common/io/virtio/virtio_main.c
+++ b/usr/src/uts/common/io/virtio/virtio_main.c
@@ -1440,7 +1440,7 @@ virtio_interrupts_setup(virtio_t *vio, int allow_types)
 		return (DDI_FAILURE);
 	}
 
-	if (allow_types != 0) {
+	if (allow_types != VIRTIO_ANY_INTR_TYPE) {
 		/*
 		 * Restrict the possible interrupt types at the request of the
 		 * driver.
diff --git a/usr/src/uts/common/sys/Makefile b/usr/src/uts/common/sys/Makefile
index c761028491..3c22bb04ce 100644
--- a/usr/src/uts/common/sys/Makefile
+++ b/usr/src/uts/common/sys/Makefile
@@ -660,6 +660,7 @@ CHKHDRS=			\
 	vfstab.h		\
 	vgareg.h		\
 	videodev2.h		\
+	vio9p.h			\
 	visual_io.h		\
 	vlan.h			\
 	vm.h			\
diff --git a/usr/src/uts/common/sys/lockstat.h b/usr/src/uts/common/sys/lockstat.h
index 308b96326c..f2a10dcc6b 100644
--- a/usr/src/uts/common/sys/lockstat.h
+++ b/usr/src/uts/common/sys/lockstat.h
@@ -26,8 +26,6 @@
 #ifndef _SYS_LOCKSTAT_H
 #define	_SYS_LOCKSTAT_H
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/dtrace.h>
 
 #ifdef	__cplusplus
@@ -123,7 +121,7 @@ extern void (*lockstat_probe)(dtrace_id_t, uintptr_t, uintptr_t,
 
 extern int lockstat_active_threads(void);
 extern int lockstat_depth(void);
-extern void lockstat_hot_patch(void);
+extern void lockstat_hotpatch_probe(int);
 
 /*
  * Macros to record lockstat probes.
@@ -175,10 +173,10 @@ extern void lockstat_hot_patch(void);
 			if (t_spin) {					\
 				t_spin = gethrtime_waitfree() - t_spin;	\
 				t_spin = CLAMP32(t_spin);		\
-			} 						\
+			}						\
 			(*lockstat_probe)(id, (uintptr_t)(lp), t_spin,	\
 			0, 0, 0);					\
-		} 							\
+		}							\
 		curthread->t_lockstat--;				\
 	}
 
diff --git a/usr/src/uts/common/sys/vio9p.h b/usr/src/uts/common/sys/vio9p.h
new file mode 100644
index 0000000000..359862e797
--- /dev/null
+++ b/usr/src/uts/common/sys/vio9p.h
@@ -0,0 +1,49 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2022 Oxide Computer Company
+ */
+
+#ifndef _SYS_VIO9P_H
+#define	_SYS_VIO9P_H
+
+/*
+ * VIRTIO 9P DRIVER
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * If the hypervisor supports mount tags through the VIRTIO_9P_F_MOUNT_TAG
+ * feature, they will have at most this many bytes:
+ */
+#define	VIRTIO_9P_TAGLEN		32
+
+/*
+ * ioctl(2) support for 9P channel devices:
+ */
+#define	VIO9P_IOC_BASE			(('9' << 16) | ('P' << 8))
+#define	VIO9P_IOC_MOUNT_TAG		(VIO9P_IOC_BASE | 0x01)
+
+/*
+ * Buffer size for the VIO9P_IOC_MOUNT_TAG ioctl, which includes one byte
+ * beyond the maximum tag length for NUL termination:
+ */
+#define	VIO9P_MOUNT_TAG_SIZE		(VIRTIO_9P_TAGLEN + 1)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_VIO9P_H */
diff --git a/usr/src/uts/i86pc/Makefile.workarounds b/usr/src/uts/i86pc/Makefile.workarounds
index 2300e74393..21a6ff9155 100644
--- a/usr/src/uts/i86pc/Makefile.workarounds
+++ b/usr/src/uts/i86pc/Makefile.workarounds
@@ -101,9 +101,10 @@ WORKAROUND_DEFS += -DOPTERON_ERRATUM_131
 WORKAROUND_DEFS += -DOPTERON_WORKAROUND_6336786
 
 #
-# Mutex primitives don't work as expected
+# Potential Violation of Read Ordering Rules Between Semaphore Operations and
+# Unlocked Read-Modify-Write Instructions
 #
-WORKAROUND_DEFS += -DOPTERON_WORKAROUND_6323525
+WORKAROUND_DEFS += -DOPTERON_ERRATUM_147
 
 #
 # Some Registered DIMMs incompatible with address parity feature
diff --git a/usr/src/uts/i86pc/os/cpuid.c b/usr/src/uts/i86pc/os/cpuid.c
index 0b42cad19d..35476bb9ed 100644
--- a/usr/src/uts/i86pc/os/cpuid.c
+++ b/usr/src/uts/i86pc/os/cpuid.c
@@ -6281,7 +6281,7 @@ cpuid_opteron_erratum(cpu_t *cpu, uint_t erratum)
 			return (!(regs.cp_edx & 0x100));
 		}
 		return (0);
-	case 6323525:
+	case 147:
 		/*
 		 * This erratum (K8 #147) is not present on family 10 and newer.
 		 */
diff --git a/usr/src/uts/i86pc/os/mp_startup.c b/usr/src/uts/i86pc/os/mp_startup.c
index e90dc6466a..5310c79db9 100644
--- a/usr/src/uts/i86pc/os/mp_startup.c
+++ b/usr/src/uts/i86pc/os/mp_startup.c
@@ -30,6 +30,7 @@
  * Copyright 2020 Joyent, Inc.
  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2022 Oxide Computer Company
  */
 
 #include <sys/types.h>
@@ -669,8 +670,8 @@ int opteron_workaround_6336786;	/* non-zero -> WA relevant and applied */
 int opteron_workaround_6336786_UP = 0;	/* Not needed for UP */
 #endif
 
-#if defined(OPTERON_WORKAROUND_6323525)
-int opteron_workaround_6323525;	/* if non-zero -> at least one cpu has it */
+#if defined(OPTERON_ERRATUM_147)
+int opteron_erratum_147;	/* if non-zero -> at least one cpu has it */
 #endif
 
 #if defined(OPTERON_ERRATUM_298)
@@ -1166,8 +1167,8 @@ workaround_errata(struct cpu *cpu)
 	 * 'Revision Guide for AMD Athlon 64 and AMD Opteron Processors'
 	 * document 25759.
 	 */
-	if (cpuid_opteron_erratum(cpu, 6323525) > 0) {
-#if defined(OPTERON_WORKAROUND_6323525)
+	if (cpuid_opteron_erratum(cpu, 147) > 0) {
+#if defined(OPTERON_ERRATUM_147)
 		/*
 		 * This problem only occurs with 2 or more cores. If bit in
 		 * MSR_AMD_BU_CFG set, then not applicable. The workaround
@@ -1178,8 +1179,8 @@ workaround_errata(struct cpu *cpu)
 		 * It is too early in boot to call the patch routine so
 		 * set erratum variable to be done in startup_end().
 		 */
-		if (opteron_workaround_6323525) {
-			opteron_workaround_6323525++;
+		if (opteron_erratum_147) {
+			opteron_erratum_147++;
 #if defined(__xpv)
 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2)) {
 			if (DOMAIN_IS_INITDOMAIN(xen_info)) {
@@ -1188,7 +1189,7 @@ workaround_errata(struct cpu *cpu)
 				 *	operations are supported?
 				 */
 				if (xpv_nr_phys_cpus() > 1)
-					opteron_workaround_6323525++;
+					opteron_erratum_147++;
 			} else {
 				/*
 				 * We have no way to tell how many physical
@@ -1196,18 +1197,18 @@ workaround_errata(struct cpu *cpu)
 				 * has the problem, so enable the workaround
 				 * unconditionally (at some performance cost).
 				 */
-				opteron_workaround_6323525++;
+				opteron_erratum_147++;
 			}
 #else	/* __xpv */
 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2) &&
 		    ((opteron_get_nnodes() *
 		    cpuid_get_ncpu_per_chip(cpu)) > 1)) {
 			if ((xrdmsr(MSR_AMD_BU_CFG) & (UINT64_C(1) << 33)) == 0)
-				opteron_workaround_6323525++;
+				opteron_erratum_147++;
 #endif	/* __xpv */
 		}
 #else
-		workaround_warning(cpu, 6323525);
+		workaround_warning(cpu, 147);
 		missing++;
 #endif
 	}
@@ -1306,9 +1307,9 @@ workaround_errata_end()
 	if (opteron_workaround_6336786)
 		workaround_applied(6336786);
 #endif
-#if defined(OPTERON_WORKAROUND_6323525)
-	if (opteron_workaround_6323525)
-		workaround_applied(6323525);
+#if defined(OPTERON_ERRATUM_147)
+	if (opteron_erratum_147)
+		workaround_applied(147);
 #endif
 #if defined(OPTERON_ERRATUM_298)
 	if (opteron_erratum_298) {
diff --git a/usr/src/uts/i86pc/os/startup.c b/usr/src/uts/i86pc/os/startup.c
index 416b3fb520..a8d3a35908 100644
--- a/usr/src/uts/i86pc/os/startup.c
+++ b/usr/src/uts/i86pc/os/startup.c
@@ -25,7 +25,7 @@
  * Copyright 2017 Nexenta Systems, Inc.
  * Copyright 2020 Joyent, Inc.
  * Copyright (c) 2015 by Delphix. All rights reserved.
- * Copyright 2020 Oxide Computer Company
+ * Copyright 2022 Oxide Computer Company
  * Copyright (c) 2020 Carlos Neira <cneirabustos@gmail.com>
  */
 /*
@@ -2125,9 +2125,9 @@ startup_end(void)
 	 */
 	cpu_event_init();
 
-#if defined(OPTERON_WORKAROUND_6323525)
-	if (opteron_workaround_6323525)
-		patch_workaround_6323525();
+#if defined(OPTERON_ERRATUM_147)
+	if (opteron_erratum_147)
+		patch_erratum_147();
 #endif
 	/*
 	 * If needed, load TOD module now so that ddi_get_time(9F) etc. work
diff --git a/usr/src/uts/intel/Makefile.intel b/usr/src/uts/intel/Makefile.intel
index b635e100e1..cb668e8a4b 100644
--- a/usr/src/uts/intel/Makefile.intel
+++ b/usr/src/uts/intel/Makefile.intel
@@ -418,6 +418,9 @@ DRV_KMODS	+= vioblk
 DRV_KMODS	+= vioif
 DRV_KMODS	+= vioscsi
 
+# Virtio 9P transport driver
+DRV_KMODS	+= vio9p
+
 #
 #	DTrace and DTrace Providers
 #
diff --git a/usr/src/uts/intel/ml/lock_prim.s b/usr/src/uts/intel/ml/lock_prim.s
index 4267561bf7..ce2e093343 100644
--- a/usr/src/uts/intel/ml/lock_prim.s
+++ b/usr/src/uts/intel/ml/lock_prim.s
@@ -25,6 +25,7 @@
 
 /*
  * Copyright 2019 Joyent, Inc.
+ * Copyright 2022 Oxide Computer Company
  */
 
 #include "assym.h"
@@ -36,6 +37,38 @@
 #include <sys/rwlock_impl.h>
 #include <sys/lockstat.h>
 
+
+#if defined(OPTERON_ERRATUM_147)
+
+/*
+ * Leave space for an lfence to be inserted if required by a CPU which suffers
+ * from this erratum.  Pad (with nops) the location for the lfence so that it
+ * is adequately aligned for atomic hotpatching.
+ */
+#define	ERRATUM147_PATCH_POINT(name)	\
+	.align	4, NOP_INSTR;		\
+./**/name/**/_147_patch_point:		\
+	nop;				\
+	nop;				\
+	nop;				\
+	nop;
+
+#else /* defined(OPTERON_ERRATUM_147) */
+
+/* Empty macro so ifdefs are not required for all of the erratum sites. */
+#define	ERRATUM147_PATCH_POINT(name)
+
+#endif /* defined(OPTERON_ERRATUM_147) */
+
+/*
+ * Patch point for lockstat probes.  When the associated probe is disabled, it
+ * will 'ret' from the function.  It is hotpatched to allow execution to fall
+ * through when the probe is enabled.
+ */
+#define	LOCKSTAT_RET(name)		\
+./**/name/**/_lockstat_patch_point:	\
+	ret;
+
 /*
  * lock_try(lp), ulock_try(lp)
  *	- returns non-zero on success.
@@ -51,8 +84,8 @@
 	movzbq	%dl, %rax
 	xchgb	%dl, (%rdi)
 	xorb	%dl, %al
-.lock_try_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(lock_try)
+
 	testb	%al, %al
 	jnz	0f
 	ret
@@ -79,7 +112,7 @@
 
 	movq	%rdi, %r12		/* preserve lock ptr for debugging */
 	leaq	.ulock_panic_msg(%rip), %rdi
-	pushq	%rbp			/* align stack properly */
+	pushq	%rbp
 	movq	%rsp, %rbp
 	xorl	%eax, %eax		/* clear for varargs */
 	call	panic
@@ -107,8 +140,8 @@ ulock_pass:
 
 	ENTRY(lock_clear)
 	movb	$0, (%rdi)
-.lock_clear_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(lock_clear)
+
 	movq	%rdi, %rsi			/* rsi = lock addr */
 	movq	%gs:CPU_THREAD, %rdx		/* rdx = thread addr */
 	movl	$LS_LOCK_CLEAR_RELEASE, %edi	/* edi = event */
@@ -122,7 +155,7 @@ ulock_pass:
 	jb	ulock_clr		/*	 uaddr < kernelbase, proceed */
 
 	leaq	.ulock_clear_msg(%rip), %rdi
-	pushq	%rbp			/* align stack properly */
+	pushq	%rbp
 	movq	%rsp, %rbp
 	xorl	%eax, %eax		/* clear for varargs */
 	call	panic
@@ -163,12 +196,13 @@ ulock_clr:
 	movq	16(%rsp), %rdx		/* rdx = old pil addr */
 	movw	%ax, (%rdx)		/* store old pil */
 	leave
-.lock_set_spl_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(lock_set_spl)
+
 	movq	%rdi, %rsi		/* rsi = lock addr */
 	movq	%gs:CPU_THREAD, %rdx	/* rdx = thread addr */
 	movl	$LS_LOCK_SET_SPL_ACQUIRE, %edi
 	jmp	lockstat_wrapper
+
 .lss_miss:
 	movl	8(%rsp), %esi		/* new_pil */
 	movq	16(%rsp), %rdx		/* old_pil_addr */
@@ -197,8 +231,8 @@ ulock_clr:
 	xchgb	%dl, (%rdi)		/* try to set lock */
 	testb	%dl, %dl		/* did we get it? */
 	jnz	lock_set_spin		/* no, go to C for the hard case */
-.lock_set_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(lock_set)
+
 	movq	%rdi, %rsi		/* rsi = lock addr */
 	movq	%gs:CPU_THREAD, %rdx	/* rdx = thread addr */
 	movl	$LS_LOCK_SET_ACQUIRE, %edi
@@ -210,40 +244,21 @@ ulock_clr:
  */
 
 	ENTRY(lock_clear_splx)
-	movb	$0, (%rdi)		/* clear lock */
-.lock_clear_splx_lockstat_patch_point:
-	jmp	0f
-0:
-	movl	%esi, %edi		/* arg for splx */
-	jmp	splx			/* let splx do its thing */
-.lock_clear_splx_lockstat:
-	pushq	%rbp			/* align stack properly */
+	pushq	%rbp
 	movq	%rsp, %rbp
-	subq	$16, %rsp		/* space to save args across splx */
-	movq	%rdi, 8(%rsp)		/* save lock ptr across splx call */
-	movl	%esi, %edi		/* arg for splx */
-	call	splx			/* lower the priority */
-	movq	8(%rsp), %rsi		/* rsi = lock ptr */
-	leave				/* unwind stack */
+	pushq	%rdi		/* save lp across call for lockstat */
+	movb	$0, (%rdi)	/* clear lock */
+	movl	%esi, %edi	/* arg for splx */
+	call	splx		/* let splx do its thing */
+	popq	%rsi		/* retreive lp for lockstat */
+	leave
+	LOCKSTAT_RET(lock_clear_splx)
+
 	movq	%gs:CPU_THREAD, %rdx	/* rdx = thread addr */
 	movl	$LS_LOCK_CLEAR_SPLX_RELEASE, %edi
 	jmp	lockstat_wrapper
 	SET_SIZE(lock_clear_splx)
 
-#if defined(__GNUC_AS__)
-#define	LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_VAL	\
-	(.lock_clear_splx_lockstat - .lock_clear_splx_lockstat_patch_point - 2)
-
-#define LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_POINT	\
-	(.lock_clear_splx_lockstat_patch_point + 1)
-#else
-#define	LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_VAL	\
-	[.lock_clear_splx_lockstat - .lock_clear_splx_lockstat_patch_point - 2]
-
-#define LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_POINT	\
-	[.lock_clear_splx_lockstat_patch_point + 1]
-#endif
-
 /*
  * mutex_enter() and mutex_exit().
  *
@@ -261,11 +276,6 @@ ulock_clr:
  * If we interrupt a thread in mutex_exit() that has not yet cleared
  * the lock, cmnint() resets its PC back to the beginning of
  * mutex_exit() so it will check again for waiters when it resumes.
- *
- * The lockstat code below is activated when the lockstat driver
- * calls lockstat_hot_patch() to hot-patch the kernel mutex code.
- * Note that we don't need to test lockstat_event_mask here -- we won't
- * patch this code in unless we're gathering ADAPTIVE_HOLD lockstats.
  */
 
 	ENTRY_NP(mutex_enter)
@@ -274,29 +284,27 @@ ulock_clr:
 	lock
 	cmpxchgq %rdx, (%rdi)
 	jnz	mutex_vector_enter
-.mutex_enter_lockstat_patch_point:
-#if defined(OPTERON_WORKAROUND_6323525)
-.mutex_enter_6323525_patch_point:
-	ret					/* nop space for lfence */
-	nop
-	nop
-.mutex_enter_lockstat_6323525_patch_point:	/* new patch point if lfence */
-	nop
-#else	/* OPTERON_WORKAROUND_6323525 */
-	ret
-#endif	/* OPTERON_WORKAROUND_6323525 */
+
+	ERRATUM147_PATCH_POINT(mutex_enter)
+
+	LOCKSTAT_RET(mutex_enter)
+
 	movq	%rdi, %rsi
 	movl	$LS_MUTEX_ENTER_ACQUIRE, %edi
+	jmp	lockstat_wrapper
+	SET_SIZE(mutex_enter)
+
+
 /*
  * expects %rdx=thread, %rsi=lock, %edi=lockstat event
  */
-	ALTENTRY(lockstat_wrapper)
+	ENTRY_NP(lockstat_wrapper)
 	incb	T_LOCKSTAT(%rdx)		/* curthread->t_lockstat++ */
 	leaq	lockstat_probemap(%rip), %rax
 	movl	(%rax, %rdi, DTRACE_IDSIZE), %eax
 	testl	%eax, %eax			/* check for non-zero probe */
 	jz	1f
-	pushq	%rbp				/* align stack properly */
+	pushq	%rbp
 	movq	%rsp, %rbp
 	movl	%eax, %edi
 	movq	lockstat_probe, %rax
@@ -308,7 +316,6 @@ ulock_clr:
 	movl	$1, %eax			/* return success if tryenter */
 	ret
 	SET_SIZE(lockstat_wrapper)
-	SET_SIZE(mutex_enter)
 
 /*
  * expects %rcx=thread, %rdx=arg, %rsi=lock, %edi=lockstat event
@@ -319,7 +326,7 @@ ulock_clr:
 	movl	(%rax, %rdi, DTRACE_IDSIZE), %eax
 	testl	%eax, %eax			/* check for non-zero probe */
 	jz	1f
-	pushq	%rbp				/* align stack properly */
+	pushq	%rbp
 	movq	%rsp, %rbp
 	movl	%eax, %edi
 	movq	lockstat_probe, %rax
@@ -340,20 +347,13 @@ ulock_clr:
 	cmpxchgq %rdx, (%rdi)
 	jnz	mutex_vector_tryenter
 	not	%eax				/* return success (nonzero) */
-#if defined(OPTERON_WORKAROUND_6323525)
-.mutex_tryenter_lockstat_patch_point:
-.mutex_tryenter_6323525_patch_point:
-	ret					/* nop space for lfence */
-	nop
-	nop
-.mutex_tryenter_lockstat_6323525_patch_point:	/* new patch point if lfence */
-	nop
-#else	/* OPTERON_WORKAROUND_6323525 */
-.mutex_tryenter_lockstat_patch_point:
-	ret
-#endif	/* OPTERON_WORKAROUND_6323525 */
+
+	ERRATUM147_PATCH_POINT(mutex_tryenter)
+
+	LOCKSTAT_RET(mutex_tryenter)
+
 	movq	%rdi, %rsi
-	movl	$LS_MUTEX_ENTER_ACQUIRE, %edi
+	movl	$LS_MUTEX_TRYENTER_ACQUIRE, %edi
 	jmp	lockstat_wrapper
 	SET_SIZE(mutex_tryenter)
 
@@ -364,15 +364,10 @@ ulock_clr:
 	cmpxchgq %rdx, (%rdi)
 	jnz	0f
 	not	%eax				/* return success (nonzero) */
-#if defined(OPTERON_WORKAROUND_6323525)
-.mutex_atryenter_6323525_patch_point:
-	ret					/* nop space for lfence */
-	nop
-	nop
-	nop
-#else	/* OPTERON_WORKAROUND_6323525 */
+
+	ERRATUM147_PATCH_POINT(mutex_atryenter)
+
 	ret
-#endif	/* OPTERON_WORKAROUND_6323525 */
 0:
 	xorl	%eax, %eax			/* return failure */
 	ret
@@ -415,8 +410,8 @@ mutex_exit_critical_start:		/* If interrupted, restart here */
 	jne	mutex_vector_exit		/* wrong type or wrong owner */
 	movq	$0, (%rdi)			/* clear owner AND lock */
 .mutex_exit_critical_end:
-.mutex_exit_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(mutex_exit)
+
 	movq	%rdi, %rsi
 	movl	$LS_MUTEX_EXIT_RELEASE, %edi
 	jmp	lockstat_wrapper
@@ -448,13 +443,14 @@ mutex_exit_critical_size:
 	lock
 	cmpxchgq %rdx, (%rdi)			/* try to grab read lock */
 	jnz	rw_enter_sleep
-.rw_read_enter_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(rw_read_enter)
+
 	movq	%gs:CPU_THREAD, %rcx		/* rcx = thread ptr */
 	movq	%rdi, %rsi			/* rsi = lock ptr */
 	movl	$LS_RW_ENTER_ACQUIRE, %edi
 	movl	$RW_READER, %edx
 	jmp	lockstat_wrapper_arg
+
 .rw_write_enter:
 	movq	%gs:CPU_THREAD, %rdx
 	orq	$RW_WRITE_LOCKED, %rdx		/* rdx = write-locked value */
@@ -463,18 +459,9 @@ mutex_exit_critical_size:
 	cmpxchgq %rdx, (%rdi)			/* try to grab write lock */
 	jnz	rw_enter_sleep
 
-#if defined(OPTERON_WORKAROUND_6323525)
-.rw_write_enter_lockstat_patch_point:
-.rw_write_enter_6323525_patch_point:
-	ret
-	nop
-	nop
-.rw_write_enter_lockstat_6323525_patch_point:
-	nop
-#else	/* OPTERON_WORKAROUND_6323525 */
-.rw_write_enter_lockstat_patch_point:
-	ret
-#endif	/* OPTERON_WORKAROUND_6323525 */
+	ERRATUM147_PATCH_POINT(rw_write_enter)
+
+	LOCKSTAT_RET(rw_write_enter)
 
 	movq	%gs:CPU_THREAD, %rcx		/* rcx = thread ptr */
 	movq	%rdi, %rsi			/* rsi = lock ptr */
@@ -492,13 +479,14 @@ mutex_exit_critical_size:
 	lock
 	cmpxchgq %rdx, (%rdi)			/* try to drop read lock */
 	jnz	rw_exit_wakeup
-.rw_read_exit_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(rw_read_exit)
+
 	movq	%gs:CPU_THREAD, %rcx		/* rcx = thread ptr */
 	movq	%rdi, %rsi			/* rsi = lock ptr */
 	movl	$LS_RW_EXIT_RELEASE, %edi
 	movl	$RW_READER, %edx
 	jmp	lockstat_wrapper_arg
+
 .rw_not_single_reader:
 	testl	$RW_WRITE_LOCKED, %eax	/* write-locked or write-wanted? */
 	jnz	.rw_write_exit
@@ -513,8 +501,8 @@ mutex_exit_critical_size:
 	lock
 	cmpxchgq %rdx, (%rdi)			/* try to drop read lock */
 	jnz	rw_exit_wakeup
-.rw_write_exit_lockstat_patch_point:
-	ret
+	LOCKSTAT_RET(rw_write_exit)
+
 	movq	%gs:CPU_THREAD, %rcx		/* rcx = thread ptr */
 	movq	%rdi, %rsi			/* rsi - lock ptr */
 	movl	$LS_RW_EXIT_RELEASE, %edi
@@ -522,149 +510,131 @@ mutex_exit_critical_size:
 	jmp	lockstat_wrapper_arg
 	SET_SIZE(rw_exit)
 
-#if defined(OPTERON_WORKAROUND_6323525)
+#if defined(OPTERON_ERRATUM_147)
 
 /*
- * If it is necessary to patch the lock enter routines with the lfence
- * workaround, workaround_6323525_patched is set to a non-zero value so that
- * the lockstat_hat_patch routine can patch to the new location of the 'ret'
- * instruction.
+ * Track if erratum 147 workaround has been hotpatched into place.
  */
-	DGDEF3(workaround_6323525_patched, 4, 4)
+	DGDEF3(erratum_147_patched, 4, 4)
 	.long	0
 
-#define HOT_MUTEX_PATCH(srcaddr, dstaddr, size)	\
-	movq	$size, %rbx;			\
-	movq	$dstaddr, %r13;			\
-	addq	%rbx, %r13;			\
-	movq	$srcaddr, %r12;			\
-	addq	%rbx, %r12;			\
-0:						\
-	decq	%r13;				\
-	decq	%r12;				\
-	movzbl	(%r12), %esi;			\
-	movq	$1, %rdx;			\
-	movq	%r13, %rdi;			\
-	call	hot_patch_kernel_text;		\
-	decq	%rbx;				\
-	testq	%rbx, %rbx;			\
-	jg	0b;
+#define HOT_MUTEX_PATCH(iaddr, insn_reg)	\
+	movq	$iaddr, %rdi;		\
+	movl	%insn_reg, %esi;	\
+	movl	$4, %edx;		\
+	call	hot_patch_kernel_text;
+
 
 /*
- * patch_workaround_6323525: provide workaround for 6323525
+ * void
+ * patch_erratum_147(void)
+ *
+ * Patch lock operations to work around erratum 147.
  *
  * The workaround is to place a fencing instruction (lfence) between the
  * mutex operation and the subsequent read-modify-write instruction.
- *
- * This routine hot patches the lfence instruction on top of the space
- * reserved by nops in the lock enter routines.
  */
-	ENTRY_NP(patch_workaround_6323525)
+
+	ENTRY_NP(patch_erratum_147)
 	pushq	%rbp
 	movq	%rsp, %rbp
 	pushq	%r12
-	pushq	%r13
-	pushq	%rbx
 
 	/*
-	 * lockstat_hot_patch() to use the alternate lockstat workaround
-	 * 6323525 patch points (points past the lfence instruction to the
-	 * new ret) when workaround_6323525_patched is set.
+	 * Patch `nop; nop; nop; nop` sequence to `lfence; nop`.  Since those
+	 * patch points have been aligned to a 4-byte boundary, we can be
+	 * confident that hot_patch_kernel_text() will be able to proceed
+	 * safely and successfully.
 	 */
-	movl	$1, workaround_6323525_patched
+	movl	$0x90e8ae0f, %r12d
+	HOT_MUTEX_PATCH(.mutex_enter_147_patch_point, r12d)
+	HOT_MUTEX_PATCH(.mutex_tryenter_147_patch_point, r12d)
+	HOT_MUTEX_PATCH(.mutex_atryenter_147_patch_point, r12d)
+	HOT_MUTEX_PATCH(.rw_write_enter_147_patch_point, r12d)
 
-	/*
-	 * patch ret/nop/nop/nop to lfence/ret at the end of the lock enter
-	 * routines. The 4 bytes are patched in reverse order so that the
-	 * the existing ret is overwritten last. This provides lock enter
-	 * sanity during the intermediate patching stages.
-	 */
-	HOT_MUTEX_PATCH(_lfence_insn, .mutex_enter_6323525_patch_point, 4)
-	HOT_MUTEX_PATCH(_lfence_insn, .mutex_tryenter_6323525_patch_point, 4)
-	HOT_MUTEX_PATCH(_lfence_insn, .mutex_atryenter_6323525_patch_point, 4)
-	HOT_MUTEX_PATCH(_lfence_insn, .rw_write_enter_6323525_patch_point, 4)
+	/* Record that erratum 147 points have been hotpatched */
+	movl	$1, erratum_147_patched
 
-	popq	%rbx
-	popq	%r13
 	popq	%r12
 	movq	%rbp, %rsp
 	popq	%rbp
 	ret
-_lfence_insn:
-	lfence
-	ret
-	SET_SIZE(patch_workaround_6323525)
+	SET_SIZE(patch_erratum_147)
+
+#endif	/* OPTERON_ERRATUM_147 */
 
+	/*
+	 * void
+	 * lockstat_hotpatch_site(caddr_t instr_addr, int do_enable)
+	 */
+	ENTRY(lockstat_hotpatch_site)
+	pushq	%rbp
+	movq	%rsp, %rbp
+	pushq	%rdi
+	pushq	%rsi
 
-#endif	/* OPTERON_WORKAROUND_6323525 */
+	testl	%esi, %esi
+	jz	.do_disable
 
+	/* enable the probe (replace ret with nop) */
+	movl	$NOP_INSTR, %esi
+	movl	$1, %edx
+	call	hot_patch_kernel_text
+	leave
+	ret
 
-#define	HOT_PATCH(addr, event, active_instr, normal_instr, len)	\
-	movq	$normal_instr, %rsi;		\
-	movq	$active_instr, %rdi;		\
-	leaq	lockstat_probemap(%rip), %rax;	\
-	movl	_MUL(event, DTRACE_IDSIZE)(%rax), %eax;	\
-	testl	%eax, %eax;			\
-	jz	9f;				\
-	movq	%rdi, %rsi;			\
-9:						\
-	movq	$len, %rdx;			\
-	movq	$addr, %rdi;			\
+.do_disable:
+	/* disable the probe (replace nop with ret) */
+	movl	$RET_INSTR, %esi
+	movl	$1, %edx
 	call	hot_patch_kernel_text
+	leave
+	ret
+	SET_SIZE(lockstat_hotpatch_site)
+
+#define	HOT_PATCH_MATCH(name, probe, reg)			\
+	cmpl	$probe, %reg;					\
+	jne	1f;						\
+	leaq	lockstat_probemap(%rip), %rax;			\
+	movl	_MUL(probe, DTRACE_IDSIZE)(%rax), %esi;		\
+	movq	$./**/name/**/_lockstat_patch_point, %rdi;	\
+	call	lockstat_hotpatch_site;				\
+	1:
+
+/*
+ * void
+ * lockstat_hotpatch_probe(int ls_probe)
+ *
+ * Given a lockstat probe identifier, hotpatch any associated lockstat
+ * primitive routine(s) so they fall through into the lockstat_probe() call (if
+ * the probe is enabled) or return normally (when the probe is disabled).
+ */
 
-	ENTRY(lockstat_hot_patch)
-	pushq	%rbp			/* align stack properly */
+	ENTRY(lockstat_hotpatch_probe)
+	pushq	%rbp
 	movq	%rsp, %rbp
+	pushq	%r12
+	movl	%edi, %r12d
 
-#if defined(OPTERON_WORKAROUND_6323525)
-	cmpl	$0, workaround_6323525_patched
-	je	1f
-	HOT_PATCH(.mutex_enter_lockstat_6323525_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.mutex_tryenter_lockstat_6323525_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_write_enter_lockstat_6323525_patch_point,
-		LS_RW_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	jmp	2f
-1:
-	HOT_PATCH(.mutex_enter_lockstat_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.mutex_tryenter_lockstat_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_write_enter_lockstat_patch_point,
-		LS_RW_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-2:
-#else	/* OPTERON_WORKAROUND_6323525 */
-	HOT_PATCH(.mutex_enter_lockstat_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.mutex_tryenter_lockstat_patch_point,
-		LS_MUTEX_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_write_enter_lockstat_patch_point,
-		LS_RW_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-#endif	/* !OPTERON_WORKAROUND_6323525 */
-	HOT_PATCH(.mutex_exit_lockstat_patch_point,
-		LS_MUTEX_EXIT_RELEASE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_read_enter_lockstat_patch_point,
-		LS_RW_ENTER_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_write_exit_lockstat_patch_point,
-		LS_RW_EXIT_RELEASE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.rw_read_exit_lockstat_patch_point,
-		LS_RW_EXIT_RELEASE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.lock_set_lockstat_patch_point,
-		LS_LOCK_SET_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.lock_try_lockstat_patch_point,
-		LS_LOCK_TRY_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.lock_clear_lockstat_patch_point,
-		LS_LOCK_CLEAR_RELEASE, NOP_INSTR, RET_INSTR, 1)
-	HOT_PATCH(.lock_set_spl_lockstat_patch_point,
-		LS_LOCK_SET_SPL_ACQUIRE, NOP_INSTR, RET_INSTR, 1)
-
-	HOT_PATCH(LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_POINT,
-		LS_LOCK_CLEAR_SPLX_RELEASE,
-		LOCK_CLEAR_SPLX_LOCKSTAT_PATCH_VAL, 0, 1);
-	leave			/* unwind stack */
+	HOT_PATCH_MATCH(mutex_enter, LS_MUTEX_ENTER_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(mutex_tryenter, LS_MUTEX_TRYENTER_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(mutex_exit, LS_MUTEX_EXIT_RELEASE, r12d)
+
+	HOT_PATCH_MATCH(rw_write_enter, LS_RW_ENTER_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(rw_read_enter, LS_RW_ENTER_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(rw_write_exit, LS_RW_EXIT_RELEASE, r12d)
+	HOT_PATCH_MATCH(rw_read_exit, LS_RW_EXIT_RELEASE, r12d)
+
+	HOT_PATCH_MATCH(lock_set, LS_LOCK_SET_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(lock_try, LS_LOCK_TRY_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(lock_clear, LS_LOCK_CLEAR_RELEASE, r12d)
+	HOT_PATCH_MATCH(lock_set_spl, LS_LOCK_SET_SPL_ACQUIRE, r12d)
+	HOT_PATCH_MATCH(lock_clear_splx, LS_LOCK_CLEAR_SPLX_RELEASE, r12d)
+
+	popq	%r12
+	leave
 	ret
-	SET_SIZE(lockstat_hot_patch)
+	SET_SIZE(lockstat_hotpatch_probe)
 
 	ENTRY(membar_enter)
 	ALTENTRY(membar_exit)
diff --git a/usr/src/uts/intel/sys/x86_archext.h b/usr/src/uts/intel/sys/x86_archext.h
index ab62bd6deb..c16d430c2e 100644
--- a/usr/src/uts/intel/sys/x86_archext.h
+++ b/usr/src/uts/intel/sys/x86_archext.h
@@ -1366,9 +1366,9 @@ extern int opteron_erratum_100;
 extern int opteron_erratum_121;
 #endif
 
-#if defined(OPTERON_WORKAROUND_6323525)
-extern int opteron_workaround_6323525;
-extern void patch_workaround_6323525(void);
+#if defined(OPTERON_ERRATUM_147)
+extern int opteron_erratum_147;
+extern void patch_erratum_147(void);
 #endif
 
 #if !defined(__xpv)
diff --git a/usr/src/uts/intel/vio9p/Makefile b/usr/src/uts/intel/vio9p/Makefile
new file mode 100644
index 0000000000..0774962e52
--- /dev/null
+++ b/usr/src/uts/intel/vio9p/Makefile
@@ -0,0 +1,67 @@
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright 2022 Oxide Computer Company
+#
+
+#
+# Path to the base of the uts directory tree (usually /usr/src/uts).
+#
+UTSBASE =		../..
+
+#
+# Define the module and object file sets.
+#
+MODULE =		vio9p
+OBJECTS =		$(VIO9P_OBJS:%=$(OBJS_DIR)/%)
+ROOTMODULE =		$(ROOT_DRV_DIR)/$(MODULE)
+
+#
+# Include common rules.
+#
+include $(UTSBASE)/intel/Makefile.intel
+
+#
+# Define targets
+#
+ALL_TARGET =		$(BINARY)
+INSTALL_TARGET =	$(BINARY) $(ROOTMODULE)
+
+#
+# Overrides
+#
+INC_PATH +=		-I$(UTSBASE)/common/io/virtio
+
+#
+# Driver depends on virtio
+#
+LDFLAGS +=		-N misc/virtio
+
+#
+# Default build targets.
+#
+.KEEP_STATE:
+
+def: $(DEF_DEPS)
+
+all: $(ALL_DEPS)
+
+clean: $(CLEAN_DEPS)
+
+clobber: $(CLOBBER_DEPS)
+
+install: $(INSTALL_DEPS)
+
+#
+# Include common targets.
+#
+include $(UTSBASE)/intel/Makefile.targ