1 files changed, 361 insertions, 0 deletions
diff --git a/usr/src/cmd/bhyve/mem.c b/usr/src/cmd/bhyve/mem.c
new file mode 100644
index 0000000000..85e56af10b
--- /dev/null
+++ b/usr/src/cmd/bhyve/mem.c
@@ -0,0 +1,361 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2012 NetApp, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Memory ranges are represented with an RB tree. On insertion, the range
+ * is checked for overlaps. On lookup, the key has the same base and limit
+ * so it can be searched within the range.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/tree.h>
+#include <machine/vmm.h>
+#include <machine/vmm_instruction_emul.h>
+
+#include <assert.h>
+#include <err.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "mem.h"
+
+struct mmio_rb_range {
+	RB_ENTRY(mmio_rb_range)	mr_link;	/* RB tree links */
+	struct mem_range	mr_param;
+	uint64_t                mr_base;
+	uint64_t                mr_end;
+};
+
+struct mmio_rb_tree;
+RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
+
+RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback;
+
+/*
+ * Per-vCPU cache. Since most accesses from a vCPU will be to
+ * consecutive addresses in a range, it makes sense to cache the
+ * result of a lookup.
+ */
+static struct mmio_rb_range	*mmio_hint[VM_MAXCPU];
+
+static pthread_rwlock_t mmio_rwlock;
+
+static int
+mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b)
+{
+	if (a->mr_end < b->mr_base)
+		return (-1);
+	else if (a->mr_base > b->mr_end)
+		return (1);
+	return (0);
+}
+
+static int
+mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr,
+    struct mmio_rb_range **entry)
+{
+	struct mmio_rb_range find, *res;
+
+	find.mr_base = find.mr_end = addr;
+
+	res = RB_FIND(mmio_rb_tree, rbt, &find);
+
+	if (res != NULL) {
+		*entry = res;
+		return (0);
+	}
+	
+	return (ENOENT);
+}
+
+static int
+mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new)
+{
+	struct mmio_rb_range *overlap;
+
+	overlap = RB_INSERT(mmio_rb_tree, rbt, new);
+
+	if (overlap != NULL) {
+#ifdef RB_DEBUG
+		printf("overlap detected: new %lx:%lx, tree %lx:%lx\n",
+		       new->mr_base, new->mr_end,
+		       overlap->mr_base, overlap->mr_end);
+#endif
+
+		return (EEXIST);
+	}
+
+	return (0);
+}
+
+#if 0
+static void
+mmio_rb_dump(struct mmio_rb_tree *rbt)
+{
+	int perror;
+	struct mmio_rb_range *np;
+
+	pthread_rwlock_rdlock(&mmio_rwlock);
+	RB_FOREACH(np, mmio_rb_tree, rbt) {
+		printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end,
+		       np->mr_param.name);
+	}
+	perror = pthread_rwlock_unlock(&mmio_rwlock);
+	assert(perror == 0);
+}
+#endif
+
+RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
+
+typedef int (mem_cb_t)(struct vmctx *ctx, int vcpu, uint64_t gpa,
+    struct mem_range *mr, void *arg);
+
+static int
+mem_read(void *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg)
+{
+	int error;
+	struct mem_range *mr = arg;
+
+	error = (*mr->handler)(ctx, vcpu, MEM_F_READ, gpa, size,
+			       rval, mr->arg1, mr->arg2);
+	return (error);
+}
+
+static int
+mem_write(void *ctx, int vcpu, uint64_t gpa, uint64_t wval, int size, void *arg)
+{
+	int error;
+	struct mem_range *mr = arg;
+
+	error = (*mr->handler)(ctx, vcpu, MEM_F_WRITE, gpa, size,
+			       &wval, mr->arg1, mr->arg2);
+	return (error);
+}
+
+static int
+access_memory(struct vmctx *ctx, int vcpu, uint64_t paddr, mem_cb_t *cb,
+    void *arg)
+{
+	struct mmio_rb_range *entry;
+	int err, perror, immutable;
+	
+	pthread_rwlock_rdlock(&mmio_rwlock);
+	/*
+	 * First check the per-vCPU cache
+	 */
+	if (mmio_hint[vcpu] &&
+	    paddr >= mmio_hint[vcpu]->mr_base &&
+	    paddr <= mmio_hint[vcpu]->mr_end) {
+		entry = mmio_hint[vcpu];
+	} else
+		entry = NULL;
+
+	if (entry == NULL) {
+		if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) {
+			/* Update the per-vCPU cache */
+			mmio_hint[vcpu] = entry;			
+		} else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) {
+			perror = pthread_rwlock_unlock(&mmio_rwlock);
+			assert(perror == 0);
+			return (ESRCH);
+		}
+	}
+
+	assert(entry != NULL);
+
+	/*
+	 * An 'immutable' memory range is guaranteed to be never removed
+	 * so there is no need to hold 'mmio_rwlock' while calling the
+	 * handler.
+	 *
+	 * XXX writes to the PCIR_COMMAND register can cause register_mem()
+	 * to be called. If the guest is using PCI extended config space
+	 * to modify the PCIR_COMMAND register then register_mem() can
+	 * deadlock on 'mmio_rwlock'. However by registering the extended
+	 * config space window as 'immutable' the deadlock can be avoided.
+	 */
+	immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE);
+	if (immutable) {
+		perror = pthread_rwlock_unlock(&mmio_rwlock);
+		assert(perror == 0);
+	}
+
+	err = cb(ctx, vcpu, paddr, &entry->mr_param, arg);
+
+	if (!immutable) {
+		perror = pthread_rwlock_unlock(&mmio_rwlock);
+		assert(perror == 0);
+	}
+
+
+	return (err);
+}
+
+struct emulate_mem_args {
+	struct vie *vie;
+	struct vm_guest_paging *paging;
+};
+
+static int
+emulate_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr,
+    void *arg)
+{
+	struct emulate_mem_args *ema;
+
+	ema = arg;
+	return (vmm_emulate_instruction(ctx, vcpu, paddr, ema->vie, ema->paging,
+	    mem_read, mem_write, mr));
+}
+
+int
+emulate_mem(struct vmctx *ctx, int vcpu, uint64_t paddr, struct vie *vie,
+    struct vm_guest_paging *paging)
+
+{
+	struct emulate_mem_args ema;
+
+	ema.vie = vie;
+	ema.paging = paging;
+	return (access_memory(ctx, vcpu, paddr, emulate_mem_cb, &ema));
+}
+
+struct read_mem_args {
+	uint64_t *rval;
+	int size;
+};
+
+static int
+read_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr,
+    void *arg)
+{
+	struct read_mem_args *rma;
+
+	rma = arg;
+	return (mr->handler(ctx, vcpu, MEM_F_READ, paddr, rma->size,
+	    rma->rval, mr->arg1, mr->arg2));
+}
+
+int
+read_mem(struct vmctx *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size)
+{
+	struct read_mem_args rma;
+
+	rma.rval = rval;
+	rma.size = size;
+	return (access_memory(ctx, vcpu, gpa, read_mem_cb, &rma));
+}
+
+static int
+register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp)
+{
+	struct mmio_rb_range *entry, *mrp;
+	int err, perror;
+
+	err = 0;
+
+	mrp = malloc(sizeof(struct mmio_rb_range));
+	if (mrp == NULL) {
+		warn("%s: couldn't allocate memory for mrp\n",
+		     __func__);
+		err = ENOMEM;
+	} else {
+		mrp->mr_param = *memp;
+		mrp->mr_base = memp->base;
+		mrp->mr_end = memp->base + memp->size - 1;
+		pthread_rwlock_wrlock(&mmio_rwlock);
+		if (mmio_rb_lookup(rbt, memp->base, &entry) != 0)
+			err = mmio_rb_add(rbt, mrp);
+		perror = pthread_rwlock_unlock(&mmio_rwlock);
+		assert(perror == 0);
+		if (err)
+			free(mrp);
+	}
+
+	return (err);
+}
+
+int
+register_mem(struct mem_range *memp)
+{
+
+	return (register_mem_int(&mmio_rb_root, memp));
+}
+
+int
+register_mem_fallback(struct mem_range *memp)
+{
+
+	return (register_mem_int(&mmio_rb_fallback, memp));
+}
+
+int 
+unregister_mem(struct mem_range *memp)
+{
+	struct mem_range *mr;
+	struct mmio_rb_range *entry = NULL;
+	int err, perror, i;
+	
+	pthread_rwlock_wrlock(&mmio_rwlock);
+	err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry);
+	if (err == 0) {
+		mr = &entry->mr_param;
+		assert(mr->name == memp->name);
+		assert(mr->base == memp->base && mr->size == memp->size); 
+		assert((mr->flags & MEM_F_IMMUTABLE) == 0);
+		RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry);
+
+		/* flush Per-vCPU cache */	
+		for (i=0; i < VM_MAXCPU; i++) {
+			if (mmio_hint[i] == entry)
+				mmio_hint[i] = NULL;
+		}
+	}
+	perror = pthread_rwlock_unlock(&mmio_rwlock);
+	assert(perror == 0);
+
+	if (entry)
+		free(entry);
+	
+	return (err);
+}
+
+void
+init_mem(void)
+{
+
+	RB_INIT(&mmio_rb_root);
+	RB_INIT(&mmio_rb_fallback);
+	pthread_rwlock_init(&mmio_rwlock, NULL);
+}