1 files changed, 749 insertions, 0 deletions

diff --git a/usr/src/uts/intel/os/hma.c b/usr/src/uts/intel/os/hma.c
new file mode 100644
index 0000000000..215243ea98
--- /dev/null
+++ b/usr/src/uts/intel/os/hma.c
@@ -0,0 +1,749 @@
+/*
+ * 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 2019 Joyent, Inc.
+ * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
+ */
+
+#include <sys/cpuvar.h>
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/machsystm.h>
+#include <sys/archsystm.h>
+#include <sys/controlregs.h>
+#include <sys/x86_archext.h>
+#include <sys/id_space.h>
+#include <sys/hma.h>
+#include <sys/cmn_err.h>
+#include <vm/hat.h>
+#include <vm/as.h>
+
+struct hma_reg {
+	const char	*hr_name;
+	list_node_t	hr_node;
+};
+
+static kmutex_t hma_lock;
+static list_t hma_registrations;
+static boolean_t hma_exclusive = B_FALSE;
+int hma_disable = 0;
+
+static boolean_t hma_vmx_ready = B_FALSE;
+static const char *hma_vmx_error = NULL;
+static id_space_t *hma_vmx_vpid;
+
+/*
+ * The bulk of HMA state (VMX & SVM) is protected by cpu_lock, rather than a
+ * mutex specific to the module.  It (cpu_lock) is already required for the
+ * state needed to perform setup on all CPUs, so it was a natural fit to
+ * protect this data too.
+ */
+typedef enum hma_cpu_state {
+	HCS_UNINITIALIZED = 0,
+	HCS_READY,
+	HCS_ERROR
+} hma_cpu_state_t;
+static hma_cpu_state_t hma_cpu_status[NCPU];
+
+/* HMA-internal tracking of optional VMX capabilities */
+typedef enum {
+	HVC_EPT		= (1 << 0),
+	HVC_VPID	= (1 << 1),
+	HVC_INVEPT_ONE	= (1 << 2),
+	HVC_INVEPT_ALL	= (1 << 3),
+} hma_vmx_capab_t;
+
+static void *hma_vmx_vmxon_page[NCPU];
+static uintptr_t hma_vmx_vmxon_pa[NCPU];
+static uint32_t hma_vmx_revision;
+static hma_vmx_capab_t hma_vmx_capabs = 0;
+
+static boolean_t hma_svm_ready = B_FALSE;
+static const char *hma_svm_error = NULL;
+static uint32_t hma_svm_features;
+static uint32_t hma_svm_max_asid;
+
+static void *hma_svm_hsave_page[NCPU];
+static uintptr_t hma_svm_hsave_pa[NCPU];
+
+static hma_svm_asid_t hma_svm_cpu_asid[NCPU];
+
+
+static int hma_vmx_init(void);
+static int hma_svm_init(void);
+
+/* Helpers from ml/hma_asm.s */
+int hma_vmx_do_invept(int, uintptr_t);
+int hma_vmx_vmxon(uintptr_t);
+
+void
+hma_init(void)
+{
+	mutex_init(&hma_lock, NULL, MUTEX_DEFAULT, NULL);
+	list_create(&hma_registrations, sizeof (struct hma_reg),
+	    offsetof(struct hma_reg, hr_node));
+
+	if (hma_disable != 0) {
+		cmn_err(CE_CONT, "?hma_init: disabled");
+		return;
+	}
+
+	switch (cpuid_getvendor(CPU)) {
+	case X86_VENDOR_Intel:
+		(void) hma_vmx_init();
+		break;
+	case X86_VENDOR_AMD:
+	case X86_VENDOR_HYGON:
+		(void) hma_svm_init();
+		break;
+	default:
+		break;
+	}
+}
+
+static hma_reg_t *
+hma_register_backend(const char *name)
+{
+	struct hma_reg *reg;
+	boolean_t is_ready;
+
+	ASSERT(MUTEX_HELD(&hma_lock));
+
+	switch (cpuid_getvendor(CPU)) {
+	case X86_VENDOR_Intel:
+		is_ready = hma_vmx_ready;
+		break;
+	case X86_VENDOR_AMD:
+	case X86_VENDOR_HYGON:
+		is_ready = hma_svm_ready;
+		break;
+	default:
+		is_ready = B_FALSE;
+		break;
+	}
+
+	if (!is_ready)
+		return (NULL);
+
+	reg = kmem_zalloc(sizeof (*reg), KM_SLEEP);
+	reg->hr_name = name;
+	list_insert_tail(&hma_registrations, reg);
+
+	return (reg);
+}
+
+hma_reg_t *
+hma_register(const char *name)
+{
+	struct hma_reg *reg = NULL;
+
+	VERIFY(name != NULL);
+
+	mutex_enter(&hma_lock);
+
+	if (!hma_exclusive)
+		reg = hma_register_backend(name);
+
+	mutex_exit(&hma_lock);
+
+	return (reg);
+}
+
+hma_reg_t *
+hma_register_exclusive(const char *name)
+{
+	struct hma_reg *reg = NULL;
+
+	VERIFY(name != NULL);
+
+	mutex_enter(&hma_lock);
+
+	if (list_is_empty(&hma_registrations)) {
+		reg = hma_register_backend(name);
+		if (reg != NULL)
+			hma_exclusive = B_TRUE;
+	}
+
+	mutex_exit(&hma_lock);
+
+	return (reg);
+}
+
+void
+hma_unregister(hma_reg_t *reg)
+{
+	VERIFY(reg != NULL);
+	VERIFY(!list_is_empty(&hma_registrations));
+
+	mutex_enter(&hma_lock);
+	list_remove(&hma_registrations, reg);
+	if (hma_exclusive && list_is_empty(&hma_registrations))
+		hma_exclusive = B_FALSE;
+	mutex_exit(&hma_lock);
+	kmem_free(reg, sizeof (*reg));
+}
+
+/*
+ * VPID 0 is reserved for instances where VPID is disabled.  Some hypervisors
+ * (read: bhyve) reserve lower-order VPIDs for use in fallback behavior if
+ * unique VPIDs could not be allocated for all the vCPUs belonging to a VM.
+ */
+#define	HMA_VPID_RESERVED	NCPU
+
+uint16_t
+hma_vmx_vpid_alloc(void)
+{
+	id_t res;
+
+	/* Do not bother if the CPU lacks support */
+	if ((hma_vmx_capabs & HVC_VPID) == 0) {
+		return (0);
+	}
+
+	res = id_alloc_nosleep(hma_vmx_vpid);
+	if (res == -1) {
+		return (0);
+	} else {
+		ASSERT(res > HMA_VPID_RESERVED && res <= UINT16_MAX);
+		return (res);
+	}
+}
+
+void
+hma_vmx_vpid_free(uint16_t vpid)
+{
+	VERIFY(vpid > HMA_VPID_RESERVED);
+	id_free(hma_vmx_vpid, (id_t)vpid);
+}
+
+#define	INVEPT_SINGLE_CONTEXT	1
+#define	INVEPT_ALL_CONTEXTS	2
+
+static int
+hma_vmx_invept_xcall(xc_arg_t arg1, xc_arg_t arg2, xc_arg_t arg3 __unused)
+{
+	int flag = (int)arg1;
+	uintptr_t eptp = (uintptr_t)arg2;
+
+	ASSERT(flag == INVEPT_SINGLE_CONTEXT || flag == INVEPT_ALL_CONTEXTS);
+
+	VERIFY0(hma_vmx_do_invept(flag, eptp));
+	return (0);
+}
+
+void
+hma_vmx_invept_allcpus(uintptr_t eptp)
+{
+	int flag = -1;
+	cpuset_t set;
+
+	if ((hma_vmx_capabs & HVC_INVEPT_ONE) != 0) {
+		flag = INVEPT_SINGLE_CONTEXT;
+	} else if ((hma_vmx_capabs & HVC_INVEPT_ALL) != 0) {
+		flag = INVEPT_ALL_CONTEXTS;
+		eptp = 0;
+	} else {
+		return;
+	}
+
+	cpuset_zero(&set);
+	mutex_enter(&cpu_lock);
+
+	cpuset_or(&set, &cpu_active_set);
+	xc_call((xc_arg_t)flag, (xc_arg_t)eptp, 0, CPUSET2BV(set),
+	    hma_vmx_invept_xcall);
+
+	mutex_exit(&cpu_lock);
+}
+
+static int
+hma_vmx_cpu_vmxon(xc_arg_t arg1 __unused, xc_arg_t arg2 __unused,
+    xc_arg_t arg3 __unused)
+{
+	uint64_t fctrl;
+	processorid_t id = CPU->cpu_seqid;
+	void *vmxon_region = hma_vmx_vmxon_page[id];
+	uintptr_t vmxon_pa = hma_vmx_vmxon_pa[id];
+
+	VERIFY(vmxon_region != NULL && vmxon_pa != 0);
+
+	/*
+	 * Ensure that the VMX support and lock bits are enabled in the
+	 * feature-control MSR.
+	 */
+	fctrl = rdmsr(MSR_IA32_FEAT_CTRL);
+	if ((fctrl & IA32_FEAT_CTRL_LOCK) == 0 ||
+	    (fctrl & IA32_FEAT_CTRL_VMX_EN) == 0) {
+		fctrl = fctrl | IA32_FEAT_CTRL_VMX_EN | IA32_FEAT_CTRL_LOCK;
+		wrmsr(MSR_IA32_FEAT_CTRL, fctrl);
+	}
+
+	setcr4(getcr4() | CR4_VMXE);
+
+	if (hma_vmx_vmxon(vmxon_pa) == 0) {
+		hma_cpu_status[id] = HCS_READY;
+	} else {
+		hma_cpu_status[id] = HCS_ERROR;
+
+		/*
+		 * If VMX has already been marked active and available for the
+		 * system, then failure to perform VMXON on a newly-onlined CPU
+		 * represents a fatal problem.  Continuing on would mean
+		 * failure for any hypervisor thread which landed here.
+		 */
+		if (hma_vmx_ready) {
+			panic("VMXON failure after VMX marked ready");
+		}
+	}
+	return (0);
+}
+
+static int
+hma_vmx_cpu_setup(cpu_setup_t what, int id, void *arg __unused)
+{
+	hma_cpu_state_t state;
+
+	ASSERT(MUTEX_HELD(&cpu_lock));
+	ASSERT(id >= 0 && id < NCPU);
+
+	if (what != CPU_ON) {
+		/*
+		 * For the purposes of VMX setup, only the CPU_ON event is of
+		 * interest.  Letting VMX state linger on an offline CPU should
+		 * not cause any harm.
+		 *
+		 * This logic assumes that any offlining activity is strictly
+		 * administrative in nature and will not alter any existing
+		 * configuration (such as %cr4 bits previously set).
+		 */
+		return (0);
+	}
+
+	state = hma_cpu_status[id];
+	if (state == HCS_ERROR) {
+		return (-1);
+	}
+
+	/* Allocate the VMXON page for this CPU, if not already done */
+	if (hma_vmx_vmxon_page[id] == NULL) {
+		caddr_t va;
+		pfn_t pfn;
+
+		va = kmem_alloc(PAGESIZE, KM_SLEEP);
+		VERIFY0((uintptr_t)va & PAGEOFFSET);
+		hma_vmx_vmxon_page[id] = va;
+
+		/* Initialize the VMX revision field as expected */
+		bcopy(&hma_vmx_revision, va, sizeof (hma_vmx_revision));
+
+		/*
+		 * Cache the physical address of the VMXON page rather than
+		 * looking it up later when the potential blocking of
+		 * hat_getpfnum would be less acceptable.
+		 */
+		pfn = hat_getpfnum(kas.a_hat, va);
+		hma_vmx_vmxon_pa[id] = (pfn << PAGESHIFT);
+	} else {
+		VERIFY(hma_vmx_vmxon_pa[id] != 0);
+	}
+
+	if (state == HCS_UNINITIALIZED) {
+		cpuset_t set;
+
+		/* Activate VMX on this CPU */
+		cpuset_zero(&set);
+		cpuset_add(&set, id);
+		xc_call(0, 0, 0, CPUSET2BV(set), hma_vmx_cpu_vmxon);
+	} else {
+		VERIFY3U(state, ==, HCS_READY);
+
+		/*
+		 * If an already-initialized CPU is going back online, perform
+		 * an all-contexts invept to eliminate the possibility of
+		 * cached EPT state causing issues.
+		 */
+		if ((hma_vmx_capabs & HVC_INVEPT_ALL) != 0) {
+			cpuset_t set;
+
+			cpuset_zero(&set);
+			cpuset_add(&set, id);
+			xc_call((xc_arg_t)INVEPT_ALL_CONTEXTS, 0, 0,
+			    CPUSET2BV(set), hma_vmx_invept_xcall);
+		}
+	}
+
+	return (hma_cpu_status[id] != HCS_READY);
+}
+
+/*
+ * Determining the availability of VM execution controls is somewhat different
+ * from conventional means, where one simply checks for asserted bits in the
+ * MSR value.  Instead, these execution control MSRs are split into two halves:
+ * the lower 32-bits indicating capabilities which can be zeroed in the VMCS
+ * field and the upper 32-bits indicating capabilities which can be set to one.
+ *
+ * It is described in detail in Appendix A.3 of SDM volume 3.
+ */
+#define	VMX_CTL_ONE_SETTING(val, flag)	\
+	(((val) & ((uint64_t)(flag) << 32)) != 0)
+
+static const char *
+hma_vmx_query_details(void)
+{
+	boolean_t query_true_ctl = B_FALSE;
+	uint64_t msr;
+
+	/* The basic INS/OUTS functionality is cited as a necessary prereq */
+	msr = rdmsr(MSR_IA32_VMX_BASIC);
+	if ((msr & IA32_VMX_BASIC_INS_OUTS) == 0) {
+		return ("VMX does not support INS/OUTS");
+	}
+
+	/* Record the VMX revision for later VMXON usage */
+	hma_vmx_revision = (uint32_t)msr;
+
+	/*
+	 * Bit 55 in the VMX_BASIC MSR determines how VMX control information
+	 * can be queried.
+	 */
+	query_true_ctl = (msr & IA32_VMX_BASIC_TRUE_CTRLS) != 0;
+
+	/* Check for EPT and VPID support */
+	msr = rdmsr(query_true_ctl ?
+	    MSR_IA32_VMX_TRUE_PROCBASED_CTLS : MSR_IA32_VMX_PROCBASED_CTLS);
+	if (VMX_CTL_ONE_SETTING(msr, IA32_VMX_PROCBASED_2ND_CTLS)) {
+		msr = rdmsr(MSR_IA32_VMX_PROCBASED2_CTLS);
+		if (VMX_CTL_ONE_SETTING(msr, IA32_VMX_PROCBASED2_EPT)) {
+			hma_vmx_capabs |= HVC_EPT;
+		}
+		if (VMX_CTL_ONE_SETTING(msr, IA32_VMX_PROCBASED2_VPID)) {
+			hma_vmx_capabs |= HVC_VPID;
+		}
+	}
+
+	/* Check for INVEPT support */
+	if ((hma_vmx_capabs & HVC_EPT) != 0) {
+		msr = rdmsr(MSR_IA32_VMX_EPT_VPID_CAP);
+		if ((msr & IA32_VMX_EPT_VPID_INVEPT) != 0) {
+			if ((msr & IA32_VMX_EPT_VPID_INVEPT_SINGLE) != 0) {
+				hma_vmx_capabs |= HVC_INVEPT_ONE;
+			}
+			if ((msr & IA32_VMX_EPT_VPID_INVEPT_ALL) != 0) {
+				hma_vmx_capabs |= HVC_INVEPT_ALL;
+			}
+		}
+	}
+
+	return (NULL);
+}
+
+static int
+hma_vmx_init(void)
+{
+	cpu_t *cp;
+	uint64_t msr;
+	int err = 0;
+	const char *msg = NULL;
+
+	if (!is_x86_feature(x86_featureset, X86FSET_VMX)) {
+		msg = "CPU does not support VMX";
+		goto bail;
+	}
+
+	/* Has the BIOS set the feature-control lock bit without VMX enabled? */
+	msr = rdmsr(MSR_IA32_FEAT_CTRL);
+	if ((msr & IA32_FEAT_CTRL_LOCK) != 0 &&
+	    (msr & IA32_FEAT_CTRL_VMX_EN) == 0) {
+		msg = "VMX support disabled by BIOS";
+		goto bail;
+	}
+
+	msg = hma_vmx_query_details();
+	if (msg != NULL) {
+		goto bail;
+	}
+
+	mutex_enter(&cpu_lock);
+	/* Perform VMX configuration for already-online CPUs. */
+	cp = cpu_active;
+	do {
+		err = hma_vmx_cpu_setup(CPU_ON, cp->cpu_seqid, NULL);
+		if (err != 0) {
+			msg = "failure during VMXON setup";
+			mutex_exit(&cpu_lock);
+			goto bail;
+		}
+	} while ((cp = cp->cpu_next_onln) != cpu_active);
+
+	/*
+	 * Register callback for later-onlined CPUs and perform other remaining
+	 * resource allocation.
+	 */
+	register_cpu_setup_func(hma_vmx_cpu_setup, NULL);
+	mutex_exit(&cpu_lock);
+
+	hma_vmx_vpid = id_space_create("hma_vmx_vpid", HMA_VPID_RESERVED + 1,
+	    UINT16_MAX);
+	hma_vmx_ready = B_TRUE;
+
+	return (0);
+
+bail:
+	hma_vmx_error = msg;
+	cmn_err(CE_NOTE, "hma_vmx_init: %s", msg);
+	return (-1);
+}
+
+#define	VMCB_FLUSH_NOTHING	0x0
+#define	VMCB_FLUSH_ALL		0x1
+#define	VMCB_FLUSH_ASID		0x3
+
+void
+hma_svm_asid_init(hma_svm_asid_t *vcp)
+{
+	/*
+	 * Initialize the generation to 0, forcing an ASID allocation on first
+	 * entry.  Leave the ASID at 0, so if the host forgoes the call to
+	 * hma_svm_asid_update(), SVM will bail on the invalid vcpu state.
+	 */
+	vcp->hsa_gen = 0;
+	vcp->hsa_asid = 0;
+}
+
+uint8_t
+hma_svm_asid_update(hma_svm_asid_t *vcp, boolean_t flush_by_asid,
+    boolean_t npt_flush)
+{
+	hma_svm_asid_t *hcp;
+	ulong_t iflag;
+	uint8_t res = VMCB_FLUSH_NOTHING;
+
+	/*
+	 * If NPT changes dictate a TLB flush and by-ASID flushing is not
+	 * supported/used, force a fresh ASID allocation.
+	 */
+	if (npt_flush && !flush_by_asid) {
+		vcp->hsa_gen = 0;
+	}
+
+	/*
+	 * It is expected that ASID resource updates will commonly be done
+	 * inside a VMM critical section where the GIF is already cleared,
+	 * preventing any possibility of interruption.  Since that cannot be
+	 * checked (there is no easy way to read the GIF), %rflags.IF is also
+	 * cleared for edge cases where an ASID update is performed outside of
+	 * such a GIF-safe critical section.
+	 */
+	iflag = intr_clear();
+
+	hcp = &hma_svm_cpu_asid[CPU->cpu_seqid];
+	if (vcp->hsa_gen != hcp->hsa_gen) {
+		hcp->hsa_asid++;
+
+		if (hcp->hsa_asid >= hma_svm_max_asid) {
+			/* Keep the ASID properly constrained */
+			hcp->hsa_asid = 1;
+			hcp->hsa_gen++;
+			if (hcp->hsa_gen == 0) {
+				/*
+				 * Stay clear of the '0' sentinel value for
+				 * generation, if wrapping around.
+				 */
+				hcp->hsa_gen = 1;
+			}
+		}
+		vcp->hsa_gen = hcp->hsa_gen;
+		vcp->hsa_asid = hcp->hsa_asid;
+
+		ASSERT(vcp->hsa_asid != 0);
+		ASSERT3U(vcp->hsa_asid, <, hma_svm_max_asid);
+
+		if (flush_by_asid) {
+			res = VMCB_FLUSH_ASID;
+		} else {
+			res = VMCB_FLUSH_ALL;
+		}
+	} else if (npt_flush) {
+		ASSERT(flush_by_asid);
+		res = VMCB_FLUSH_ASID;
+	}
+
+	intr_restore(iflag);
+	return (res);
+}
+
+static int
+hma_svm_cpu_activate(xc_arg_t arg1 __unused, xc_arg_t arg2 __unused,
+    xc_arg_t arg3 __unused)
+{
+	const processorid_t id = CPU->cpu_seqid;
+	const uintptr_t hsave_pa = hma_svm_hsave_pa[id];
+	uint64_t efer;
+
+	VERIFY(hsave_pa != 0);
+
+	/* Enable SVM via EFER */
+	efer = rdmsr(MSR_AMD_EFER);
+	efer |= AMD_EFER_SVME;
+	wrmsr(MSR_AMD_EFER, efer);
+
+	/* Setup hsave area */
+	wrmsr(MSR_AMD_VM_HSAVE_PA, hsave_pa);
+
+	hma_cpu_status[id] = HCS_READY;
+	return (0);
+}
+
+static int
+hma_svm_cpu_setup(cpu_setup_t what, int id, void *arg __unused)
+{
+	ASSERT(MUTEX_HELD(&cpu_lock));
+	ASSERT(id >= 0 && id < NCPU);
+
+	switch (what) {
+	case CPU_CONFIG:
+	case CPU_ON:
+	case CPU_INIT:
+		break;
+	default:
+		/*
+		 * Other events, such as CPU offlining, are of no interest.
+		 * Letting the SVM state linger should not cause any harm.
+		 *
+		 * This logic assumes that any offlining activity is strictly
+		 * administrative in nature and will not alter any existing
+		 * configuration (such as EFER bits previously set).
+		 */
+		return (0);
+	}
+
+	/* Perform initialization if it has not been previously attempted. */
+	if (hma_cpu_status[id] != HCS_UNINITIALIZED) {
+		return ((hma_cpu_status[id] == HCS_READY) ? 0 : -1);
+	}
+
+	/* Allocate the hsave page for this CPU */
+	if (hma_svm_hsave_page[id] == NULL) {
+		caddr_t va;
+		pfn_t pfn;
+
+		va = kmem_alloc(PAGESIZE, KM_SLEEP);
+		VERIFY0((uintptr_t)va & PAGEOFFSET);
+		hma_svm_hsave_page[id] = va;
+
+		/*
+		 * Cache the physical address of the hsave page rather than
+		 * looking it up later when the potential blocking of
+		 * hat_getpfnum would be less acceptable.
+		 */
+		pfn = hat_getpfnum(kas.a_hat, va);
+		hma_svm_hsave_pa[id] = (pfn << PAGESHIFT);
+	} else {
+		VERIFY(hma_svm_hsave_pa[id] != 0);
+	}
+
+	kpreempt_disable();
+	if (CPU->cpu_seqid == id) {
+		/* Perform svm setup directly if this CPU is the target */
+		(void) hma_svm_cpu_activate(0, 0, 0);
+		kpreempt_enable();
+	} else {
+		cpuset_t set;
+
+		/* Use a cross-call if a remote CPU is the target */
+		kpreempt_enable();
+		cpuset_zero(&set);
+		cpuset_add(&set, id);
+		xc_call(0, 0, 0, CPUSET2BV(set), hma_svm_cpu_activate);
+	}
+
+	return (hma_cpu_status[id] != HCS_READY);
+}
+
+static int
+hma_svm_init(void)
+{
+	uint64_t msr;
+	const char *msg = NULL;
+	struct cpuid_regs regs;
+	cpu_t *cp;
+
+	if (!is_x86_feature(x86_featureset, X86FSET_SVM)) {
+		msg = "CPU does not support SVM";
+		goto bail;
+	}
+
+	msr = rdmsr(MSR_AMD_VM_CR);
+	if ((msr & AMD_VM_CR_SVMDIS) != 0) {
+		msg = "SVM disabled by BIOS";
+		goto bail;
+	}
+
+	regs.cp_eax = 0x8000000a;
+	(void) cpuid_insn(NULL, &regs);
+	const uint32_t nasid = regs.cp_ebx;
+	const uint32_t feat = regs.cp_edx;
+
+	if (nasid == 0) {
+		msg = "Not enough ASIDs for guests";
+		goto bail;
+	}
+	if ((feat & CPUID_AMD_EDX_NESTED_PAGING) == 0) {
+		msg = "CPU does not support nested paging";
+		goto bail;
+	}
+	if ((feat & CPUID_AMD_EDX_NRIPS) == 0) {
+		msg = "CPU does not support NRIP save";
+		goto bail;
+	}
+
+	hma_svm_features = feat;
+	hma_svm_max_asid = nasid;
+
+	mutex_enter(&cpu_lock);
+	/* Perform SVM configuration for already-online CPUs. */
+	cp = cpu_active;
+	do {
+		int err = hma_svm_cpu_setup(CPU_ON, cp->cpu_seqid, NULL);
+		if (err != 0) {
+			msg = "failure during SVM setup";
+			mutex_exit(&cpu_lock);
+			goto bail;
+		}
+	} while ((cp = cp->cpu_next_onln) != cpu_active);
+
+	/*
+	 * Register callback for later-onlined CPUs and perform other remaining
+	 * resource allocation.
+	 */
+	register_cpu_setup_func(hma_svm_cpu_setup, NULL);
+	mutex_exit(&cpu_lock);
+
+	/* Initialize per-CPU ASID state. */
+	for (uint_t i = 0; i < NCPU; i++) {
+		/*
+		 * Skip past sentinel 0 value for generation.  Doing so for
+		 * ASID is unneeded, since it will be incremented during the
+		 * first allocation.
+		 */
+		hma_svm_cpu_asid[i].hsa_gen = 1;
+		hma_svm_cpu_asid[i].hsa_asid = 0;
+	}
+
+	hma_svm_ready = B_TRUE;
+	return (0);
+
+bail:
+	hma_svm_error = msg;
+	cmn_err(CE_NOTE, "hma_svm_init: %s", msg);
+	return (-1);
+}