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freebsd-dev/sys/amd64/vmm/amd/svm.c
Neel Natu b053814333 Allow ktr(4) tracing of all guest exceptions via the tunable 
"hw.vmm.trace_guest_exceptions".  To enable this feature set the tunable
to "1" before loading vmm.ko.

Tracing the guest exceptions can be useful when debugging guest triple faults.

Note that there is a performance impact when exception tracing is enabled
since every exception will now trigger a VM-exit.

Also, handle machine check exceptions that happen during guest execution
by vectoring to the host's machine check handler via "int $18".

Discussed with:	grehan
MFC after:	2 weeks
2014-12-23 02:14:49 +00:00

2160 lines
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/*-
* Copyright (c) 2013, Anish Gupta (akgupt3@gmail.com)
* 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 unmodified, 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 THE AUTHOR ``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 THE AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/smp.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/cpufunc.h>
#include <machine/psl.h>
#include <machine/pmap.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <machine/smp.h>
#include <machine/vmm.h>
#include <machine/vmm_dev.h>
#include <machine/vmm_instruction_emul.h>
#include "vmm_lapic.h"
#include "vmm_stat.h"
#include "vmm_ktr.h"
#include "vmm_ioport.h"
#include "vatpic.h"
#include "vlapic.h"
#include "vlapic_priv.h"
#include "x86.h"
#include "vmcb.h"
#include "svm.h"
#include "svm_softc.h"
#include "svm_msr.h"
#include "npt.h"
SYSCTL_DECL(_hw_vmm);
SYSCTL_NODE(_hw_vmm, OID_AUTO, svm, CTLFLAG_RW, NULL, NULL);
/*
* SVM CPUID function 0x8000_000A, edx bit decoding.
*/
#define AMD_CPUID_SVM_NP BIT(0) /* Nested paging or RVI */
#define AMD_CPUID_SVM_LBR BIT(1) /* Last branch virtualization */
#define AMD_CPUID_SVM_SVML BIT(2) /* SVM lock */
#define AMD_CPUID_SVM_NRIP_SAVE BIT(3) /* Next RIP is saved */
#define AMD_CPUID_SVM_TSC_RATE BIT(4) /* TSC rate control. */
#define AMD_CPUID_SVM_VMCB_CLEAN BIT(5) /* VMCB state caching */
#define AMD_CPUID_SVM_FLUSH_BY_ASID BIT(6) /* Flush by ASID */
#define AMD_CPUID_SVM_DECODE_ASSIST BIT(7) /* Decode assist */
#define AMD_CPUID_SVM_PAUSE_INC BIT(10) /* Pause intercept filter. */
#define AMD_CPUID_SVM_PAUSE_FTH BIT(12) /* Pause filter threshold */
#define VMCB_CACHE_DEFAULT (VMCB_CACHE_ASID | \
VMCB_CACHE_IOPM | \
VMCB_CACHE_I | \
VMCB_CACHE_TPR | \
VMCB_CACHE_CR2 | \
VMCB_CACHE_CR | \
VMCB_CACHE_DT | \
VMCB_CACHE_SEG | \
VMCB_CACHE_NP)
static uint32_t vmcb_clean = VMCB_CACHE_DEFAULT;
SYSCTL_INT(_hw_vmm_svm, OID_AUTO, vmcb_clean, CTLFLAG_RDTUN, &vmcb_clean,
0, NULL);
static MALLOC_DEFINE(M_SVM, "svm", "svm");
static MALLOC_DEFINE(M_SVM_VLAPIC, "svm-vlapic", "svm-vlapic");
/* Per-CPU context area. */
extern struct pcpu __pcpu[];
static uint32_t svm_feature; /* AMD SVM features. */
SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, features, CTLFLAG_RD, &svm_feature, 0,
"SVM features advertised by CPUID.8000000AH:EDX");
static int disable_npf_assist;
SYSCTL_INT(_hw_vmm_svm, OID_AUTO, disable_npf_assist, CTLFLAG_RWTUN,
&disable_npf_assist, 0, NULL);
/* Maximum ASIDs supported by the processor */
static uint32_t nasid;
SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, num_asids, CTLFLAG_RD, &nasid, 0,
"Number of ASIDs supported by this processor");
/* Current ASID generation for each host cpu */
static struct asid asid[MAXCPU];
/*
* SVM host state saved area of size 4KB for each core.
*/
static uint8_t hsave[MAXCPU][PAGE_SIZE] __aligned(PAGE_SIZE);
static VMM_STAT_AMD(VCPU_EXITINTINFO, "VM exits during event delivery");
static VMM_STAT_AMD(VCPU_INTINFO_INJECTED, "Events pending at VM entry");
static VMM_STAT_AMD(VMEXIT_VINTR, "VM exits due to interrupt window");
static int svm_setreg(void *arg, int vcpu, int ident, uint64_t val);
static __inline int
flush_by_asid(void)
{
return (svm_feature & AMD_CPUID_SVM_FLUSH_BY_ASID);
}
static __inline int
decode_assist(void)
{
return (svm_feature & AMD_CPUID_SVM_DECODE_ASSIST);
}
static void
svm_disable(void *arg __unused)
{
uint64_t efer;
efer = rdmsr(MSR_EFER);
efer &= ~EFER_SVM;
wrmsr(MSR_EFER, efer);
}
/*
* Disable SVM on all CPUs.
*/
static int
svm_cleanup(void)
{
smp_rendezvous(NULL, svm_disable, NULL, NULL);
return (0);
}
/*
* Verify that all the features required by bhyve are available.
*/
static int
check_svm_features(void)
{
u_int regs[4];
/* CPUID Fn8000_000A is for SVM */
do_cpuid(0x8000000A, regs);
svm_feature = regs[3];
nasid = regs[1];
KASSERT(nasid > 1, ("Insufficient ASIDs for guests: %#x", nasid));
/* bhyve requires the Nested Paging feature */
if (!(svm_feature & AMD_CPUID_SVM_NP)) {
printf("SVM: Nested Paging feature not available.\n");
return (ENXIO);
}
/* bhyve requires the NRIP Save feature */
if (!(svm_feature & AMD_CPUID_SVM_NRIP_SAVE)) {
printf("SVM: NRIP Save feature not available.\n");
return (ENXIO);
}
return (0);
}
static void
svm_enable(void *arg __unused)
{
uint64_t efer;
efer = rdmsr(MSR_EFER);
efer |= EFER_SVM;
wrmsr(MSR_EFER, efer);
wrmsr(MSR_VM_HSAVE_PA, vtophys(hsave[curcpu]));
}
/*
* Return 1 if SVM is enabled on this processor and 0 otherwise.
*/
static int
svm_available(void)
{
uint64_t msr;
/* Section 15.4 Enabling SVM from APM2. */
if ((amd_feature2 & AMDID2_SVM) == 0) {
printf("SVM: not available.\n");
return (0);
}
msr = rdmsr(MSR_VM_CR);
if ((msr & VM_CR_SVMDIS) != 0) {
printf("SVM: disabled by BIOS.\n");
return (0);
}
return (1);
}
static int
svm_init(int ipinum)
{
int error, cpu;
if (!svm_available())
return (ENXIO);
error = check_svm_features();
if (error)
return (error);
vmcb_clean &= VMCB_CACHE_DEFAULT;
for (cpu = 0; cpu < MAXCPU; cpu++) {
/*
* Initialize the host ASIDs to their "highest" valid values.
*
* The next ASID allocation will rollover both 'gen' and 'num'
* and start off the sequence at {1,1}.
*/
asid[cpu].gen = ~0UL;
asid[cpu].num = nasid - 1;
}
svm_msr_init();
svm_npt_init(ipinum);
/* Enable SVM on all CPUs */
smp_rendezvous(NULL, svm_enable, NULL, NULL);
return (0);
}
static void
svm_restore(void)
{
svm_enable(NULL);
}
/* Pentium compatible MSRs */
#define MSR_PENTIUM_START 0
#define MSR_PENTIUM_END 0x1FFF
/* AMD 6th generation and Intel compatible MSRs */
#define MSR_AMD6TH_START 0xC0000000UL
#define MSR_AMD6TH_END 0xC0001FFFUL
/* AMD 7th and 8th generation compatible MSRs */
#define MSR_AMD7TH_START 0xC0010000UL
#define MSR_AMD7TH_END 0xC0011FFFUL
/*
* Get the index and bit position for a MSR in permission bitmap.
* Two bits are used for each MSR: lower bit for read and higher bit for write.
*/
static int
svm_msr_index(uint64_t msr, int *index, int *bit)
{
uint32_t base, off;
*index = -1;
*bit = (msr % 4) * 2;
base = 0;
if (msr >= MSR_PENTIUM_START && msr <= MSR_PENTIUM_END) {
*index = msr / 4;
return (0);
}
base += (MSR_PENTIUM_END - MSR_PENTIUM_START + 1);
if (msr >= MSR_AMD6TH_START && msr <= MSR_AMD6TH_END) {
off = (msr - MSR_AMD6TH_START);
*index = (off + base) / 4;
return (0);
}
base += (MSR_AMD6TH_END - MSR_AMD6TH_START + 1);
if (msr >= MSR_AMD7TH_START && msr <= MSR_AMD7TH_END) {
off = (msr - MSR_AMD7TH_START);
*index = (off + base) / 4;
return (0);
}
return (EINVAL);
}
/*
* Allow vcpu to read or write the 'msr' without trapping into the hypervisor.
*/
static void
svm_msr_perm(uint8_t *perm_bitmap, uint64_t msr, bool read, bool write)
{
int index, bit, error;
error = svm_msr_index(msr, &index, &bit);
KASSERT(error == 0, ("%s: invalid msr %#lx", __func__, msr));
KASSERT(index >= 0 && index < SVM_MSR_BITMAP_SIZE,
("%s: invalid index %d for msr %#lx", __func__, index, msr));
KASSERT(bit >= 0 && bit <= 6, ("%s: invalid bit position %d "
"msr %#lx", __func__, bit, msr));
if (read)
perm_bitmap[index] &= ~(1UL << bit);
if (write)
perm_bitmap[index] &= ~(2UL << bit);
}
static void
svm_msr_rw_ok(uint8_t *perm_bitmap, uint64_t msr)
{
svm_msr_perm(perm_bitmap, msr, true, true);
}
static void
svm_msr_rd_ok(uint8_t *perm_bitmap, uint64_t msr)
{
svm_msr_perm(perm_bitmap, msr, true, false);
}
static __inline int
svm_get_intercept(struct svm_softc *sc, int vcpu, int idx, uint32_t bitmask)
{
struct vmcb_ctrl *ctrl;
KASSERT(idx >=0 && idx < 5, ("invalid intercept index %d", idx));
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
return (ctrl->intercept[idx] & bitmask ? 1 : 0);
}
static __inline void
svm_set_intercept(struct svm_softc *sc, int vcpu, int idx, uint32_t bitmask,
int enabled)
{
struct vmcb_ctrl *ctrl;
uint32_t oldval;
KASSERT(idx >=0 && idx < 5, ("invalid intercept index %d", idx));
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
oldval = ctrl->intercept[idx];
if (enabled)
ctrl->intercept[idx] |= bitmask;
else
ctrl->intercept[idx] &= ~bitmask;
if (ctrl->intercept[idx] != oldval) {
svm_set_dirty(sc, vcpu, VMCB_CACHE_I);
VCPU_CTR3(sc->vm, vcpu, "intercept[%d] modified "
"from %#x to %#x", idx, oldval, ctrl->intercept[idx]);
}
}
static __inline void
svm_disable_intercept(struct svm_softc *sc, int vcpu, int off, uint32_t bitmask)
{
svm_set_intercept(sc, vcpu, off, bitmask, 0);
}
static __inline void
svm_enable_intercept(struct svm_softc *sc, int vcpu, int off, uint32_t bitmask)
{
svm_set_intercept(sc, vcpu, off, bitmask, 1);
}
static void
vmcb_init(struct svm_softc *sc, int vcpu, uint64_t iopm_base_pa,
uint64_t msrpm_base_pa, uint64_t np_pml4)
{
struct vmcb_ctrl *ctrl;
struct vmcb_state *state;
uint32_t mask;
int n;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
state = svm_get_vmcb_state(sc, vcpu);
ctrl->iopm_base_pa = iopm_base_pa;
ctrl->msrpm_base_pa = msrpm_base_pa;
/* Enable nested paging */
ctrl->np_enable = 1;
ctrl->n_cr3 = np_pml4;
/*
* Intercept accesses to the control registers that are not shadowed
* in the VMCB - i.e. all except cr0, cr2, cr3, cr4 and cr8.
*/
for (n = 0; n < 16; n++) {
mask = (BIT(n) << 16) | BIT(n);
if (n == 0 || n == 2 || n == 3 || n == 4 || n == 8)
svm_disable_intercept(sc, vcpu, VMCB_CR_INTCPT, mask);
else
svm_enable_intercept(sc, vcpu, VMCB_CR_INTCPT, mask);
}
/*
* Intercept everything when tracing guest exceptions otherwise
* just intercept machine check exception.
*/
if (vcpu_trace_exceptions(sc->vm, vcpu)) {
for (n = 0; n < 32; n++) {
/*
* Skip unimplemented vectors in the exception bitmap.
*/
if (n == 2 || n == 9) {
continue;
}
svm_enable_intercept(sc, vcpu, VMCB_EXC_INTCPT, BIT(n));
}
} else {
svm_enable_intercept(sc, vcpu, VMCB_EXC_INTCPT, BIT(IDT_MC));
}
/* Intercept various events (for e.g. I/O, MSR and CPUID accesses) */
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IO);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_MSR);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_CPUID);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_INTR);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_INIT);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_NMI);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_SMI);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_SHUTDOWN);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_FERR_FREEZE);
/*
* From section "Canonicalization and Consistency Checks" in APMv2
* the VMRUN intercept bit must be set to pass the consistency check.
*/
svm_enable_intercept(sc, vcpu, VMCB_CTRL2_INTCPT, VMCB_INTCPT_VMRUN);
/*
* The ASID will be set to a non-zero value just before VMRUN.
*/
ctrl->asid = 0;
/*
* Section 15.21.1, Interrupt Masking in EFLAGS
* Section 15.21.2, Virtualizing APIC.TPR
*
* This must be set for %rflag and %cr8 isolation of guest and host.
*/
ctrl->v_intr_masking = 1;
/* Enable Last Branch Record aka LBR for debugging */
ctrl->lbr_virt_en = 1;
state->dbgctl = BIT(0);
/* EFER_SVM must always be set when the guest is executing */
state->efer = EFER_SVM;
/* Set up the PAT to power-on state */
state->g_pat = PAT_VALUE(0, PAT_WRITE_BACK) |
PAT_VALUE(1, PAT_WRITE_THROUGH) |
PAT_VALUE(2, PAT_UNCACHED) |
PAT_VALUE(3, PAT_UNCACHEABLE) |
PAT_VALUE(4, PAT_WRITE_BACK) |
PAT_VALUE(5, PAT_WRITE_THROUGH) |
PAT_VALUE(6, PAT_UNCACHED) |
PAT_VALUE(7, PAT_UNCACHEABLE);
}
/*
* Initialize a virtual machine.
*/
static void *
svm_vminit(struct vm *vm, pmap_t pmap)
{
struct svm_softc *svm_sc;
struct svm_vcpu *vcpu;
vm_paddr_t msrpm_pa, iopm_pa, pml4_pa;
int i;
svm_sc = malloc(sizeof (struct svm_softc), M_SVM, M_WAITOK | M_ZERO);
svm_sc->vm = vm;
svm_sc->nptp = (vm_offset_t)vtophys(pmap->pm_pml4);
/*
* Intercept read and write accesses to all MSRs.
*/
memset(svm_sc->msr_bitmap, 0xFF, sizeof(svm_sc->msr_bitmap));
/*
* Access to the following MSRs is redirected to the VMCB when the
* guest is executing. Therefore it is safe to allow the guest to
* read/write these MSRs directly without hypervisor involvement.
*/
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_GSBASE);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_FSBASE);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_KGSBASE);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_STAR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_LSTAR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_CSTAR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SF_MASK);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_CS_MSR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_ESP_MSR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_EIP_MSR);
svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_PAT);
svm_msr_rd_ok(svm_sc->msr_bitmap, MSR_TSC);
/*
* Intercept writes to make sure that the EFER_SVM bit is not cleared.
*/
svm_msr_rd_ok(svm_sc->msr_bitmap, MSR_EFER);
/* Intercept access to all I/O ports. */
memset(svm_sc->iopm_bitmap, 0xFF, sizeof(svm_sc->iopm_bitmap));
iopm_pa = vtophys(svm_sc->iopm_bitmap);
msrpm_pa = vtophys(svm_sc->msr_bitmap);
pml4_pa = svm_sc->nptp;
for (i = 0; i < VM_MAXCPU; i++) {
vcpu = svm_get_vcpu(svm_sc, i);
vcpu->lastcpu = NOCPU;
vcpu->vmcb_pa = vtophys(&vcpu->vmcb);
vmcb_init(svm_sc, i, iopm_pa, msrpm_pa, pml4_pa);
svm_msr_guest_init(svm_sc, i);
}
return (svm_sc);
}
static int
svm_cpl(struct vmcb_state *state)
{
/*
* From APMv2:
* "Retrieve the CPL from the CPL field in the VMCB, not
* from any segment DPL"
*/
return (state->cpl);
}
static enum vm_cpu_mode
svm_vcpu_mode(struct vmcb *vmcb)
{
struct vmcb_segment seg;
struct vmcb_state *state;
int error;
state = &vmcb->state;
if (state->efer & EFER_LMA) {
error = vmcb_seg(vmcb, VM_REG_GUEST_CS, &seg);
KASSERT(error == 0, ("%s: vmcb_seg(cs) error %d", __func__,
error));
/*
* Section 4.8.1 for APM2, check if Code Segment has
* Long attribute set in descriptor.
*/
if (seg.attrib & VMCB_CS_ATTRIB_L)
return (CPU_MODE_64BIT);
else
return (CPU_MODE_COMPATIBILITY);
} else if (state->cr0 & CR0_PE) {
return (CPU_MODE_PROTECTED);
} else {
return (CPU_MODE_REAL);
}
}
static enum vm_paging_mode
svm_paging_mode(uint64_t cr0, uint64_t cr4, uint64_t efer)
{
if ((cr0 & CR0_PG) == 0)
return (PAGING_MODE_FLAT);
if ((cr4 & CR4_PAE) == 0)
return (PAGING_MODE_32);
if (efer & EFER_LME)
return (PAGING_MODE_64);
else
return (PAGING_MODE_PAE);
}
/*
* ins/outs utility routines
*/
static uint64_t
svm_inout_str_index(struct svm_regctx *regs, int in)
{
uint64_t val;
val = in ? regs->sctx_rdi : regs->sctx_rsi;
return (val);
}
static uint64_t
svm_inout_str_count(struct svm_regctx *regs, int rep)
{
uint64_t val;
val = rep ? regs->sctx_rcx : 1;
return (val);
}
static void
svm_inout_str_seginfo(struct svm_softc *svm_sc, int vcpu, int64_t info1,
int in, struct vm_inout_str *vis)
{
int error, s;
if (in) {
vis->seg_name = VM_REG_GUEST_ES;
} else {
/* The segment field has standard encoding */
s = (info1 >> 10) & 0x7;
vis->seg_name = vm_segment_name(s);
}
error = vmcb_getdesc(svm_sc, vcpu, vis->seg_name, &vis->seg_desc);
KASSERT(error == 0, ("%s: svm_getdesc error %d", __func__, error));
}
static int
svm_inout_str_addrsize(uint64_t info1)
{
uint32_t size;
size = (info1 >> 7) & 0x7;
switch (size) {
case 1:
return (2); /* 16 bit */
case 2:
return (4); /* 32 bit */
case 4:
return (8); /* 64 bit */
default:
panic("%s: invalid size encoding %d", __func__, size);
}
}
static void
svm_paging_info(struct vmcb *vmcb, struct vm_guest_paging *paging)
{
struct vmcb_state *state;
state = &vmcb->state;
paging->cr3 = state->cr3;
paging->cpl = svm_cpl(state);
paging->cpu_mode = svm_vcpu_mode(vmcb);
paging->paging_mode = svm_paging_mode(state->cr0, state->cr4,
state->efer);
}
#define UNHANDLED 0
/*
* Handle guest I/O intercept.
*/
static int
svm_handle_io(struct svm_softc *svm_sc, int vcpu, struct vm_exit *vmexit)
{
struct vmcb_ctrl *ctrl;
struct vmcb_state *state;
struct svm_regctx *regs;
struct vm_inout_str *vis;
uint64_t info1;
int inout_string;
state = svm_get_vmcb_state(svm_sc, vcpu);
ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
regs = svm_get_guest_regctx(svm_sc, vcpu);
info1 = ctrl->exitinfo1;
inout_string = info1 & BIT(2) ? 1 : 0;
/*
* The effective segment number in EXITINFO1[12:10] is populated
* only if the processor has the DecodeAssist capability.
*
* XXX this is not specified explicitly in APMv2 but can be verified
* empirically.
*/
if (inout_string && !decode_assist())
return (UNHANDLED);
vmexit->exitcode = VM_EXITCODE_INOUT;
vmexit->u.inout.in = (info1 & BIT(0)) ? 1 : 0;
vmexit->u.inout.string = inout_string;
vmexit->u.inout.rep = (info1 & BIT(3)) ? 1 : 0;
vmexit->u.inout.bytes = (info1 >> 4) & 0x7;
vmexit->u.inout.port = (uint16_t)(info1 >> 16);
vmexit->u.inout.eax = (uint32_t)(state->rax);
if (inout_string) {
vmexit->exitcode = VM_EXITCODE_INOUT_STR;
vis = &vmexit->u.inout_str;
svm_paging_info(svm_get_vmcb(svm_sc, vcpu), &vis->paging);
vis->rflags = state->rflags;
vis->cr0 = state->cr0;
vis->index = svm_inout_str_index(regs, vmexit->u.inout.in);
vis->count = svm_inout_str_count(regs, vmexit->u.inout.rep);
vis->addrsize = svm_inout_str_addrsize(info1);
svm_inout_str_seginfo(svm_sc, vcpu, info1,
vmexit->u.inout.in, vis);
}
return (UNHANDLED);
}
static int
npf_fault_type(uint64_t exitinfo1)
{
if (exitinfo1 & VMCB_NPF_INFO1_W)
return (VM_PROT_WRITE);
else if (exitinfo1 & VMCB_NPF_INFO1_ID)
return (VM_PROT_EXECUTE);
else
return (VM_PROT_READ);
}
static bool
svm_npf_emul_fault(uint64_t exitinfo1)
{
if (exitinfo1 & VMCB_NPF_INFO1_ID) {
return (false);
}
if (exitinfo1 & VMCB_NPF_INFO1_GPT) {
return (false);
}
if ((exitinfo1 & VMCB_NPF_INFO1_GPA) == 0) {
return (false);
}
return (true);
}
static void
svm_handle_inst_emul(struct vmcb *vmcb, uint64_t gpa, struct vm_exit *vmexit)
{
struct vm_guest_paging *paging;
struct vmcb_segment seg;
struct vmcb_ctrl *ctrl;
char *inst_bytes;
int error, inst_len;
ctrl = &vmcb->ctrl;
paging = &vmexit->u.inst_emul.paging;
vmexit->exitcode = VM_EXITCODE_INST_EMUL;
vmexit->u.inst_emul.gpa = gpa;
vmexit->u.inst_emul.gla = VIE_INVALID_GLA;
svm_paging_info(vmcb, paging);
error = vmcb_seg(vmcb, VM_REG_GUEST_CS, &seg);
KASSERT(error == 0, ("%s: vmcb_seg(CS) error %d", __func__, error));
switch(paging->cpu_mode) {
case CPU_MODE_PROTECTED:
case CPU_MODE_COMPATIBILITY:
/*
* Section 4.8.1 of APM2, Default Operand Size or D bit.
*/
vmexit->u.inst_emul.cs_d = (seg.attrib & VMCB_CS_ATTRIB_D) ?
1 : 0;
break;
default:
vmexit->u.inst_emul.cs_d = 0;
break;
}
/*
* Copy the instruction bytes into 'vie' if available.
*/
if (decode_assist() && !disable_npf_assist) {
inst_len = ctrl->inst_len;
inst_bytes = ctrl->inst_bytes;
} else {
inst_len = 0;
inst_bytes = NULL;
}
vie_init(&vmexit->u.inst_emul.vie, inst_bytes, inst_len);
}
#ifdef KTR
static const char *
intrtype_to_str(int intr_type)
{
switch (intr_type) {
case VMCB_EVENTINJ_TYPE_INTR:
return ("hwintr");
case VMCB_EVENTINJ_TYPE_NMI:
return ("nmi");
case VMCB_EVENTINJ_TYPE_INTn:
return ("swintr");
case VMCB_EVENTINJ_TYPE_EXCEPTION:
return ("exception");
default:
panic("%s: unknown intr_type %d", __func__, intr_type);
}
}
#endif
/*
* Inject an event to vcpu as described in section 15.20, "Event injection".
*/
static void
svm_eventinject(struct svm_softc *sc, int vcpu, int intr_type, int vector,
uint32_t error, bool ec_valid)
{
struct vmcb_ctrl *ctrl;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) == 0,
("%s: event already pending %#lx", __func__, ctrl->eventinj));
KASSERT(vector >=0 && vector <= 255, ("%s: invalid vector %d",
__func__, vector));
switch (intr_type) {
case VMCB_EVENTINJ_TYPE_INTR:
case VMCB_EVENTINJ_TYPE_NMI:
case VMCB_EVENTINJ_TYPE_INTn:
break;
case VMCB_EVENTINJ_TYPE_EXCEPTION:
if (vector >= 0 && vector <= 31 && vector != 2)
break;
/* FALLTHROUGH */
default:
panic("%s: invalid intr_type/vector: %d/%d", __func__,
intr_type, vector);
}
ctrl->eventinj = vector | (intr_type << 8) | VMCB_EVENTINJ_VALID;
if (ec_valid) {
ctrl->eventinj |= VMCB_EVENTINJ_EC_VALID;
ctrl->eventinj |= (uint64_t)error << 32;
VCPU_CTR3(sc->vm, vcpu, "Injecting %s at vector %d errcode %#x",
intrtype_to_str(intr_type), vector, error);
} else {
VCPU_CTR2(sc->vm, vcpu, "Injecting %s at vector %d",
intrtype_to_str(intr_type), vector);
}
}
static void
svm_update_virqinfo(struct svm_softc *sc, int vcpu)
{
struct vm *vm;
struct vlapic *vlapic;
struct vmcb_ctrl *ctrl;
int pending;
vm = sc->vm;
vlapic = vm_lapic(vm, vcpu);
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
/* Update %cr8 in the emulated vlapic */
vlapic_set_cr8(vlapic, ctrl->v_tpr);
/*
* If V_IRQ indicates that the interrupt injection attempted on then
* last VMRUN was successful then update the vlapic accordingly.
*/
if (ctrl->v_intr_vector != 0) {
pending = ctrl->v_irq;
KASSERT(ctrl->v_intr_vector >= 16, ("%s: invalid "
"v_intr_vector %d", __func__, ctrl->v_intr_vector));
KASSERT(!ctrl->v_ign_tpr, ("%s: invalid v_ign_tpr", __func__));
VCPU_CTR2(vm, vcpu, "v_intr_vector %d %s", ctrl->v_intr_vector,
pending ? "pending" : "accepted");
if (!pending)
vlapic_intr_accepted(vlapic, ctrl->v_intr_vector);
}
}
static void
svm_save_intinfo(struct svm_softc *svm_sc, int vcpu)
{
struct vmcb_ctrl *ctrl;
uint64_t intinfo;
ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
intinfo = ctrl->exitintinfo;
if (!VMCB_EXITINTINFO_VALID(intinfo))
return;
/*
* From APMv2, Section "Intercepts during IDT interrupt delivery"
*
* If a #VMEXIT happened during event delivery then record the event
* that was being delivered.
*/
VCPU_CTR2(svm_sc->vm, vcpu, "SVM:Pending INTINFO(0x%lx), vector=%d.\n",
intinfo, VMCB_EXITINTINFO_VECTOR(intinfo));
vmm_stat_incr(svm_sc->vm, vcpu, VCPU_EXITINTINFO, 1);
vm_exit_intinfo(svm_sc->vm, vcpu, intinfo);
}
static __inline int
vintr_intercept_enabled(struct svm_softc *sc, int vcpu)
{
return (svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_VINTR));
}
static __inline void
enable_intr_window_exiting(struct svm_softc *sc, int vcpu)
{
struct vmcb_ctrl *ctrl;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
if (ctrl->v_irq && ctrl->v_intr_vector == 0) {
KASSERT(ctrl->v_ign_tpr, ("%s: invalid v_ign_tpr", __func__));
KASSERT(vintr_intercept_enabled(sc, vcpu),
("%s: vintr intercept should be enabled", __func__));
return;
}
VCPU_CTR0(sc->vm, vcpu, "Enable intr window exiting");
ctrl->v_irq = 1;
ctrl->v_ign_tpr = 1;
ctrl->v_intr_vector = 0;
svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_VINTR);
}
static __inline void
disable_intr_window_exiting(struct svm_softc *sc, int vcpu)
{
struct vmcb_ctrl *ctrl;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
if (!ctrl->v_irq && ctrl->v_intr_vector == 0) {
KASSERT(!vintr_intercept_enabled(sc, vcpu),
("%s: vintr intercept should be disabled", __func__));
return;
}
#ifdef KTR
if (ctrl->v_intr_vector == 0)
VCPU_CTR0(sc->vm, vcpu, "Disable intr window exiting");
else
VCPU_CTR0(sc->vm, vcpu, "Clearing V_IRQ interrupt injection");
#endif
ctrl->v_irq = 0;
ctrl->v_intr_vector = 0;
svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
svm_disable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_VINTR);
}
static int
svm_modify_intr_shadow(struct svm_softc *sc, int vcpu, uint64_t val)
{
struct vmcb_ctrl *ctrl;
int oldval, newval;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
oldval = ctrl->intr_shadow;
newval = val ? 1 : 0;
if (newval != oldval) {
ctrl->intr_shadow = newval;
VCPU_CTR1(sc->vm, vcpu, "Setting intr_shadow to %d", newval);
}
return (0);
}
static int
svm_get_intr_shadow(struct svm_softc *sc, int vcpu, uint64_t *val)
{
struct vmcb_ctrl *ctrl;
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
*val = ctrl->intr_shadow;
return (0);
}
/*
* Once an NMI is injected it blocks delivery of further NMIs until the handler
* executes an IRET. The IRET intercept is enabled when an NMI is injected to
* to track when the vcpu is done handling the NMI.
*/
static int
nmi_blocked(struct svm_softc *sc, int vcpu)
{
int blocked;
blocked = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_IRET);
return (blocked);
}
static void
enable_nmi_blocking(struct svm_softc *sc, int vcpu)
{
KASSERT(!nmi_blocked(sc, vcpu), ("vNMI already blocked"));
VCPU_CTR0(sc->vm, vcpu, "vNMI blocking enabled");
svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IRET);
}
static void
clear_nmi_blocking(struct svm_softc *sc, int vcpu)
{
int error;
KASSERT(nmi_blocked(sc, vcpu), ("vNMI already unblocked"));
VCPU_CTR0(sc->vm, vcpu, "vNMI blocking cleared");
/*
* When the IRET intercept is cleared the vcpu will attempt to execute
* the "iret" when it runs next. However, it is possible to inject
* another NMI into the vcpu before the "iret" has actually executed.
*
* For e.g. if the "iret" encounters a #NPF when accessing the stack
* it will trap back into the hypervisor. If an NMI is pending for
* the vcpu it will be injected into the guest.
*
* XXX this needs to be fixed
*/
svm_disable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IRET);
/*
* Set 'intr_shadow' to prevent an NMI from being injected on the
* immediate VMRUN.
*/
error = svm_modify_intr_shadow(sc, vcpu, 1);
KASSERT(!error, ("%s: error %d setting intr_shadow", __func__, error));
}
static int
emulate_wrmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t val,
bool *retu)
{
int error;
if (lapic_msr(num))
error = lapic_wrmsr(sc->vm, vcpu, num, val, retu);
else if (num == MSR_EFER)
error = svm_setreg(sc, vcpu, VM_REG_GUEST_EFER, val);
else
error = svm_wrmsr(sc, vcpu, num, val, retu);
return (error);
}
static int
emulate_rdmsr(struct svm_softc *sc, int vcpu, u_int num, bool *retu)
{
struct vmcb_state *state;
struct svm_regctx *ctx;
uint64_t result;
int error;
if (lapic_msr(num))
error = lapic_rdmsr(sc->vm, vcpu, num, &result, retu);
else
error = svm_rdmsr(sc, vcpu, num, &result, retu);
if (error == 0) {
state = svm_get_vmcb_state(sc, vcpu);
ctx = svm_get_guest_regctx(sc, vcpu);
state->rax = result & 0xffffffff;
ctx->sctx_rdx = result >> 32;
}
return (error);
}
#ifdef KTR
static const char *
exit_reason_to_str(uint64_t reason)
{
static char reasonbuf[32];
switch (reason) {
case VMCB_EXIT_INVALID:
return ("invalvmcb");
case VMCB_EXIT_SHUTDOWN:
return ("shutdown");
case VMCB_EXIT_NPF:
return ("nptfault");
case VMCB_EXIT_PAUSE:
return ("pause");
case VMCB_EXIT_HLT:
return ("hlt");
case VMCB_EXIT_CPUID:
return ("cpuid");
case VMCB_EXIT_IO:
return ("inout");
case VMCB_EXIT_MC:
return ("mchk");
case VMCB_EXIT_INTR:
return ("extintr");
case VMCB_EXIT_NMI:
return ("nmi");
case VMCB_EXIT_VINTR:
return ("vintr");
case VMCB_EXIT_MSR:
return ("msr");
case VMCB_EXIT_IRET:
return ("iret");
default:
snprintf(reasonbuf, sizeof(reasonbuf), "%#lx", reason);
return (reasonbuf);
}
}
#endif /* KTR */
/*
* From section "State Saved on Exit" in APMv2: nRIP is saved for all #VMEXITs
* that are due to instruction intercepts as well as MSR and IOIO intercepts
* and exceptions caused by INT3, INTO and BOUND instructions.
*
* Return 1 if the nRIP is valid and 0 otherwise.
*/
static int
nrip_valid(uint64_t exitcode)
{
switch (exitcode) {
case 0x00 ... 0x0F: /* read of CR0 through CR15 */
case 0x10 ... 0x1F: /* write of CR0 through CR15 */
case 0x20 ... 0x2F: /* read of DR0 through DR15 */
case 0x30 ... 0x3F: /* write of DR0 through DR15 */
case 0x43: /* INT3 */
case 0x44: /* INTO */
case 0x45: /* BOUND */
case 0x65 ... 0x7C: /* VMEXIT_CR0_SEL_WRITE ... VMEXIT_MSR */
case 0x80 ... 0x8D: /* VMEXIT_VMRUN ... VMEXIT_XSETBV */
return (1);
default:
return (0);
}
}
/*
* Collateral for a generic SVM VM-exit.
*/
static void
vm_exit_svm(struct vm_exit *vme, uint64_t code, uint64_t info1, uint64_t info2)
{
vme->exitcode = VM_EXITCODE_SVM;
vme->u.svm.exitcode = code;
vme->u.svm.exitinfo1 = info1;
vme->u.svm.exitinfo2 = info2;
}
static int
svm_vmexit(struct svm_softc *svm_sc, int vcpu, struct vm_exit *vmexit)
{
struct vmcb *vmcb;
struct vmcb_state *state;
struct vmcb_ctrl *ctrl;
struct svm_regctx *ctx;
struct vm_exception exception;
uint64_t code, info1, info2, val;
uint32_t eax, ecx, edx;
int error, errcode_valid, handled, idtvec, reflect;
bool retu;
ctx = svm_get_guest_regctx(svm_sc, vcpu);
vmcb = svm_get_vmcb(svm_sc, vcpu);
state = &vmcb->state;
ctrl = &vmcb->ctrl;
handled = 0;
code = ctrl->exitcode;
info1 = ctrl->exitinfo1;
info2 = ctrl->exitinfo2;
vmexit->exitcode = VM_EXITCODE_BOGUS;
vmexit->rip = state->rip;
vmexit->inst_length = nrip_valid(code) ? ctrl->nrip - state->rip : 0;
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_COUNT, 1);
/*
* #VMEXIT(INVALID) needs to be handled early because the VMCB is
* in an inconsistent state and can trigger assertions that would
* never happen otherwise.
*/
if (code == VMCB_EXIT_INVALID) {
vm_exit_svm(vmexit, code, info1, info2);
return (0);
}
KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) == 0, ("%s: event "
"injection valid bit is set %#lx", __func__, ctrl->eventinj));
KASSERT(vmexit->inst_length >= 0 && vmexit->inst_length <= 15,
("invalid inst_length %d: code (%#lx), info1 (%#lx), info2 (%#lx)",
vmexit->inst_length, code, info1, info2));
svm_update_virqinfo(svm_sc, vcpu);
svm_save_intinfo(svm_sc, vcpu);
switch (code) {
case VMCB_EXIT_IRET:
/*
* Restart execution at "iret" but with the intercept cleared.
*/
vmexit->inst_length = 0;
clear_nmi_blocking(svm_sc, vcpu);
handled = 1;
break;
case VMCB_EXIT_VINTR: /* interrupt window exiting */
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_VINTR, 1);
handled = 1;
break;
case VMCB_EXIT_INTR: /* external interrupt */
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_EXTINT, 1);
handled = 1;
break;
case VMCB_EXIT_NMI: /* external NMI */
handled = 1;
break;
case 0x40 ... 0x5F:
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_EXCEPTION, 1);
reflect = 1;
idtvec = code - 0x40;
switch (idtvec) {
case IDT_MC:
/*
* Call the machine check handler by hand. Also don't
* reflect the machine check back into the guest.
*/
reflect = 0;
VCPU_CTR0(svm_sc->vm, vcpu, "Vectoring to MCE handler");
__asm __volatile("int $18");
break;
case IDT_PF:
error = svm_setreg(svm_sc, vcpu, VM_REG_GUEST_CR2,
info2);
KASSERT(error == 0, ("%s: error %d updating cr2",
__func__, error));
/* fallthru */
case IDT_NP:
case IDT_SS:
case IDT_GP:
case IDT_AC:
case IDT_TS:
errcode_valid = 1;
break;
case IDT_DF:
errcode_valid = 1;
info1 = 0;
break;
case IDT_BP:
case IDT_OF:
case IDT_BR:
/*
* The 'nrip' field is populated for INT3, INTO and
* BOUND exceptions and this also implies that
* 'inst_length' is non-zero.
*
* Reset 'inst_length' to zero so the guest %rip at
* event injection is identical to what it was when
* the exception originally happened.
*/
VCPU_CTR2(svm_sc->vm, vcpu, "Reset inst_length from %d "
"to zero before injecting exception %d",
vmexit->inst_length, idtvec);
vmexit->inst_length = 0;
/* fallthru */
default:
errcode_valid = 0;
break;
}
KASSERT(vmexit->inst_length == 0, ("invalid inst_length (%d) "
"when reflecting exception %d into guest",
vmexit->inst_length, idtvec));
if (reflect) {
/* Reflect the exception back into the guest */
exception.vector = idtvec;
exception.error_code_valid = errcode_valid;
exception.error_code = errcode_valid ? info1 : 0;
VCPU_CTR2(svm_sc->vm, vcpu, "Reflecting exception "
"%d/%#x into the guest", exception.vector,
exception.error_code);
error = vm_inject_exception(svm_sc->vm, vcpu,
&exception);
KASSERT(error == 0, ("%s: vm_inject_exception error %d",
__func__, error));
}
handled = 1;
break;
case VMCB_EXIT_MSR: /* MSR access. */
eax = state->rax;
ecx = ctx->sctx_rcx;
edx = ctx->sctx_rdx;
retu = false;
if (info1) {
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_WRMSR, 1);
val = (uint64_t)edx << 32 | eax;
VCPU_CTR2(svm_sc->vm, vcpu, "wrmsr %#x val %#lx",
ecx, val);
if (emulate_wrmsr(svm_sc, vcpu, ecx, val, &retu)) {
vmexit->exitcode = VM_EXITCODE_WRMSR;
vmexit->u.msr.code = ecx;
vmexit->u.msr.wval = val;
} else if (!retu) {
handled = 1;
} else {
KASSERT(vmexit->exitcode != VM_EXITCODE_BOGUS,
("emulate_wrmsr retu with bogus exitcode"));
}
} else {
VCPU_CTR1(svm_sc->vm, vcpu, "rdmsr %#x", ecx);
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_RDMSR, 1);
if (emulate_rdmsr(svm_sc, vcpu, ecx, &retu)) {
vmexit->exitcode = VM_EXITCODE_RDMSR;
vmexit->u.msr.code = ecx;
} else if (!retu) {
handled = 1;
} else {
KASSERT(vmexit->exitcode != VM_EXITCODE_BOGUS,
("emulate_rdmsr retu with bogus exitcode"));
}
}
break;
case VMCB_EXIT_IO:
handled = svm_handle_io(svm_sc, vcpu, vmexit);
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_INOUT, 1);
break;
case VMCB_EXIT_CPUID:
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_CPUID, 1);
handled = x86_emulate_cpuid(svm_sc->vm, vcpu,
(uint32_t *)&state->rax,
(uint32_t *)&ctx->sctx_rbx,
(uint32_t *)&ctx->sctx_rcx,
(uint32_t *)&ctx->sctx_rdx);
break;
case VMCB_EXIT_HLT:
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_HLT, 1);
vmexit->exitcode = VM_EXITCODE_HLT;
vmexit->u.hlt.rflags = state->rflags;
break;
case VMCB_EXIT_PAUSE:
vmexit->exitcode = VM_EXITCODE_PAUSE;
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_PAUSE, 1);
break;
case VMCB_EXIT_NPF:
/* EXITINFO2 contains the faulting guest physical address */
if (info1 & VMCB_NPF_INFO1_RSV) {
VCPU_CTR2(svm_sc->vm, vcpu, "nested page fault with "
"reserved bits set: info1(%#lx) info2(%#lx)",
info1, info2);
} else if (vm_mem_allocated(svm_sc->vm, info2)) {
vmexit->exitcode = VM_EXITCODE_PAGING;
vmexit->u.paging.gpa = info2;
vmexit->u.paging.fault_type = npf_fault_type(info1);
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_NESTED_FAULT, 1);
VCPU_CTR3(svm_sc->vm, vcpu, "nested page fault "
"on gpa %#lx/%#lx at rip %#lx",
info2, info1, state->rip);
} else if (svm_npf_emul_fault(info1)) {
svm_handle_inst_emul(vmcb, info2, vmexit);
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_INST_EMUL, 1);
VCPU_CTR3(svm_sc->vm, vcpu, "inst_emul fault "
"for gpa %#lx/%#lx at rip %#lx",
info2, info1, state->rip);
}
break;
default:
vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_UNKNOWN, 1);
break;
}
VCPU_CTR4(svm_sc->vm, vcpu, "%s %s vmexit at %#lx/%d",
handled ? "handled" : "unhandled", exit_reason_to_str(code),
vmexit->rip, vmexit->inst_length);
if (handled) {
vmexit->rip += vmexit->inst_length;
vmexit->inst_length = 0;
state->rip = vmexit->rip;
} else {
if (vmexit->exitcode == VM_EXITCODE_BOGUS) {
/*
* If this VM exit was not claimed by anybody then
* treat it as a generic SVM exit.
*/
vm_exit_svm(vmexit, code, info1, info2);
} else {
/*
* The exitcode and collateral have been populated.
* The VM exit will be processed further in userland.
*/
}
}
return (handled);
}
static void
svm_inj_intinfo(struct svm_softc *svm_sc, int vcpu)
{
uint64_t intinfo;
if (!vm_entry_intinfo(svm_sc->vm, vcpu, &intinfo))
return;
KASSERT(VMCB_EXITINTINFO_VALID(intinfo), ("%s: entry intinfo is not "
"valid: %#lx", __func__, intinfo));
svm_eventinject(svm_sc, vcpu, VMCB_EXITINTINFO_TYPE(intinfo),
VMCB_EXITINTINFO_VECTOR(intinfo),
VMCB_EXITINTINFO_EC(intinfo),
VMCB_EXITINTINFO_EC_VALID(intinfo));
vmm_stat_incr(svm_sc->vm, vcpu, VCPU_INTINFO_INJECTED, 1);
VCPU_CTR1(svm_sc->vm, vcpu, "Injected entry intinfo: %#lx", intinfo);
}
/*
* Inject event to virtual cpu.
*/
static void
svm_inj_interrupts(struct svm_softc *sc, int vcpu, struct vlapic *vlapic)
{
struct vmcb_ctrl *ctrl;
struct vmcb_state *state;
uint8_t v_tpr;
int vector, need_intr_window, pending_apic_vector;
state = svm_get_vmcb_state(sc, vcpu);
ctrl = svm_get_vmcb_ctrl(sc, vcpu);
need_intr_window = 0;
pending_apic_vector = 0;
/*
* Inject pending events or exceptions for this vcpu.
*
* An event might be pending because the previous #VMEXIT happened
* during event delivery (i.e. ctrl->exitintinfo).
*
* An event might also be pending because an exception was injected
* by the hypervisor (e.g. #PF during instruction emulation).
*/
svm_inj_intinfo(sc, vcpu);
/* NMI event has priority over interrupts. */
if (vm_nmi_pending(sc->vm, vcpu)) {
if (nmi_blocked(sc, vcpu)) {
/*
* Can't inject another NMI if the guest has not
* yet executed an "iret" after the last NMI.
*/
VCPU_CTR0(sc->vm, vcpu, "Cannot inject NMI due "
"to NMI-blocking");
} else if (ctrl->intr_shadow) {
/*
* Can't inject an NMI if the vcpu is in an intr_shadow.
*/
VCPU_CTR0(sc->vm, vcpu, "Cannot inject NMI due to "
"interrupt shadow");
need_intr_window = 1;
goto done;
} else if (ctrl->eventinj & VMCB_EVENTINJ_VALID) {
/*
* If there is already an exception/interrupt pending
* then defer the NMI until after that.
*/
VCPU_CTR1(sc->vm, vcpu, "Cannot inject NMI due to "
"eventinj %#lx", ctrl->eventinj);
/*
* Use self-IPI to trigger a VM-exit as soon as
* possible after the event injection is completed.
*
* This works only if the external interrupt exiting
* is at a lower priority than the event injection.
*
* Although not explicitly specified in APMv2 the
* relative priorities were verified empirically.
*/
ipi_cpu(curcpu, IPI_AST); /* XXX vmm_ipinum? */
} else {
vm_nmi_clear(sc->vm, vcpu);
/* Inject NMI, vector number is not used */
svm_eventinject(sc, vcpu, VMCB_EVENTINJ_TYPE_NMI,
IDT_NMI, 0, false);
/* virtual NMI blocking is now in effect */
enable_nmi_blocking(sc, vcpu);
VCPU_CTR0(sc->vm, vcpu, "Injecting vNMI");
}
}
if (!vm_extint_pending(sc->vm, vcpu)) {
/*
* APIC interrupts are delivered using the V_IRQ offload.
*
* The primary benefit is that the hypervisor doesn't need to
* deal with the various conditions that inhibit interrupts.
* It also means that TPR changes via CR8 will be handled
* without any hypervisor involvement.
*
* Note that the APIC vector must remain pending in the vIRR
* until it is confirmed that it was delivered to the guest.
* This can be confirmed based on the value of V_IRQ at the
* next #VMEXIT (1 = pending, 0 = delivered).
*
* Also note that it is possible that another higher priority
* vector can become pending before this vector is delivered
* to the guest. This is alright because vcpu_notify_event()
* will send an IPI and force the vcpu to trap back into the
* hypervisor. The higher priority vector will be injected on
* the next VMRUN.
*/
if (vlapic_pending_intr(vlapic, &vector)) {
KASSERT(vector >= 16 && vector <= 255,
("invalid vector %d from local APIC", vector));
pending_apic_vector = vector;
}
goto done;
}
/* Ask the legacy pic for a vector to inject */
vatpic_pending_intr(sc->vm, &vector);
KASSERT(vector >= 0 && vector <= 255, ("invalid vector %d from INTR",
vector));
/*
* If the guest has disabled interrupts or is in an interrupt shadow
* then we cannot inject the pending interrupt.
*/
if ((state->rflags & PSL_I) == 0) {
VCPU_CTR2(sc->vm, vcpu, "Cannot inject vector %d due to "
"rflags %#lx", vector, state->rflags);
need_intr_window = 1;
goto done;
}
if (ctrl->intr_shadow) {
VCPU_CTR1(sc->vm, vcpu, "Cannot inject vector %d due to "
"interrupt shadow", vector);
need_intr_window = 1;
goto done;
}
if (ctrl->eventinj & VMCB_EVENTINJ_VALID) {
VCPU_CTR2(sc->vm, vcpu, "Cannot inject vector %d due to "
"eventinj %#lx", vector, ctrl->eventinj);
need_intr_window = 1;
goto done;
}
/*
* Legacy PIC interrupts are delivered via the event injection
* mechanism.
*/
svm_eventinject(sc, vcpu, VMCB_EVENTINJ_TYPE_INTR, vector, 0, false);
vm_extint_clear(sc->vm, vcpu);
vatpic_intr_accepted(sc->vm, vector);
/*
* Force a VM-exit as soon as the vcpu is ready to accept another
* interrupt. This is done because the PIC might have another vector
* that it wants to inject. Also, if the APIC has a pending interrupt
* that was preempted by the ExtInt then it allows us to inject the
* APIC vector as soon as possible.
*/
need_intr_window = 1;
done:
/*
* The guest can modify the TPR by writing to %CR8. In guest mode
* the processor reflects this write to V_TPR without hypervisor
* intervention.
*
* The guest can also modify the TPR by writing to it via the memory
* mapped APIC page. In this case, the write will be emulated by the
* hypervisor. For this reason V_TPR must be updated before every
* VMRUN.
*/
v_tpr = vlapic_get_cr8(vlapic);
KASSERT(v_tpr >= 0 && v_tpr <= 15, ("invalid v_tpr %#x", v_tpr));
if (ctrl->v_tpr != v_tpr) {
VCPU_CTR2(sc->vm, vcpu, "VMCB V_TPR changed from %#x to %#x",
ctrl->v_tpr, v_tpr);
ctrl->v_tpr = v_tpr;
svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
}
if (pending_apic_vector) {
/*
* If an APIC vector is being injected then interrupt window
* exiting is not possible on this VMRUN.
*/
KASSERT(!need_intr_window, ("intr_window exiting impossible"));
VCPU_CTR1(sc->vm, vcpu, "Injecting vector %d using V_IRQ",
pending_apic_vector);
ctrl->v_irq = 1;
ctrl->v_ign_tpr = 0;
ctrl->v_intr_vector = pending_apic_vector;
ctrl->v_intr_prio = pending_apic_vector >> 4;
svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
} else if (need_intr_window) {
/*
* We use V_IRQ in conjunction with the VINTR intercept to
* trap into the hypervisor as soon as a virtual interrupt
* can be delivered.
*
* Since injected events are not subject to intercept checks
* we need to ensure that the V_IRQ is not actually going to
* be delivered on VM entry. The KASSERT below enforces this.
*/
KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) != 0 ||
(state->rflags & PSL_I) == 0 || ctrl->intr_shadow,
("Bogus intr_window_exiting: eventinj (%#lx), "
"intr_shadow (%u), rflags (%#lx)",
ctrl->eventinj, ctrl->intr_shadow, state->rflags));
enable_intr_window_exiting(sc, vcpu);
} else {
disable_intr_window_exiting(sc, vcpu);
}
}
static __inline void
restore_host_tss(void)
{
struct system_segment_descriptor *tss_sd;
/*
* The TSS descriptor was in use prior to launching the guest so it
* has been marked busy.
*
* 'ltr' requires the descriptor to be marked available so change the
* type to "64-bit available TSS".
*/
tss_sd = PCPU_GET(tss);
tss_sd->sd_type = SDT_SYSTSS;
ltr(GSEL(GPROC0_SEL, SEL_KPL));
}
static void
check_asid(struct svm_softc *sc, int vcpuid, pmap_t pmap, u_int thiscpu)
{
struct svm_vcpu *vcpustate;
struct vmcb_ctrl *ctrl;
long eptgen;
bool alloc_asid;
KASSERT(CPU_ISSET(thiscpu, &pmap->pm_active), ("%s: nested pmap not "
"active on cpu %u", __func__, thiscpu));
vcpustate = svm_get_vcpu(sc, vcpuid);
ctrl = svm_get_vmcb_ctrl(sc, vcpuid);
/*
* The TLB entries associated with the vcpu's ASID are not valid
* if either of the following conditions is true:
*
* 1. The vcpu's ASID generation is different than the host cpu's
* ASID generation. This happens when the vcpu migrates to a new
* host cpu. It can also happen when the number of vcpus executing
* on a host cpu is greater than the number of ASIDs available.
*
* 2. The pmap generation number is different than the value cached in
* the 'vcpustate'. This happens when the host invalidates pages
* belonging to the guest.
*
* asidgen eptgen Action
* mismatch mismatch
* 0 0 (a)
* 0 1 (b1) or (b2)
* 1 0 (c)
* 1 1 (d)
*
* (a) There is no mismatch in eptgen or ASID generation and therefore
* no further action is needed.
*
* (b1) If the cpu supports FlushByAsid then the vcpu's ASID is
* retained and the TLB entries associated with this ASID
* are flushed by VMRUN.
*
* (b2) If the cpu does not support FlushByAsid then a new ASID is
* allocated.
*
* (c) A new ASID is allocated.
*
* (d) A new ASID is allocated.
*/
alloc_asid = false;
eptgen = pmap->pm_eptgen;
ctrl->tlb_ctrl = VMCB_TLB_FLUSH_NOTHING;
if (vcpustate->asid.gen != asid[thiscpu].gen) {
alloc_asid = true; /* (c) and (d) */
} else if (vcpustate->eptgen != eptgen) {
if (flush_by_asid())
ctrl->tlb_ctrl = VMCB_TLB_FLUSH_GUEST; /* (b1) */
else
alloc_asid = true; /* (b2) */
} else {
/*
* This is the common case (a).
*/
KASSERT(!alloc_asid, ("ASID allocation not necessary"));
KASSERT(ctrl->tlb_ctrl == VMCB_TLB_FLUSH_NOTHING,
("Invalid VMCB tlb_ctrl: %#x", ctrl->tlb_ctrl));
}
if (alloc_asid) {
if (++asid[thiscpu].num >= nasid) {
asid[thiscpu].num = 1;
if (++asid[thiscpu].gen == 0)
asid[thiscpu].gen = 1;
/*
* If this cpu does not support "flush-by-asid"
* then flush the entire TLB on a generation
* bump. Subsequent ASID allocation in this
* generation can be done without a TLB flush.
*/
if (!flush_by_asid())
ctrl->tlb_ctrl = VMCB_TLB_FLUSH_ALL;
}
vcpustate->asid.gen = asid[thiscpu].gen;
vcpustate->asid.num = asid[thiscpu].num;
ctrl->asid = vcpustate->asid.num;
svm_set_dirty(sc, vcpuid, VMCB_CACHE_ASID);
/*
* If this cpu supports "flush-by-asid" then the TLB
* was not flushed after the generation bump. The TLB
* is flushed selectively after every new ASID allocation.
*/
if (flush_by_asid())
ctrl->tlb_ctrl = VMCB_TLB_FLUSH_GUEST;
}
vcpustate->eptgen = eptgen;
KASSERT(ctrl->asid != 0, ("Guest ASID must be non-zero"));
KASSERT(ctrl->asid == vcpustate->asid.num,
("ASID mismatch: %u/%u", ctrl->asid, vcpustate->asid.num));
}
static __inline void
disable_gintr(void)
{
__asm __volatile("clgi" : : :);
}
static __inline void
enable_gintr(void)
{
__asm __volatile("stgi" : : :);
}
/*
* Start vcpu with specified RIP.
*/
static int
svm_vmrun(void *arg, int vcpu, register_t rip, pmap_t pmap,
void *rend_cookie, void *suspended_cookie)
{
struct svm_regctx *gctx;
struct svm_softc *svm_sc;
struct svm_vcpu *vcpustate;
struct vmcb_state *state;
struct vmcb_ctrl *ctrl;
struct vm_exit *vmexit;
struct vlapic *vlapic;
struct vm *vm;
uint64_t vmcb_pa;
u_int thiscpu;
int handled;
svm_sc = arg;
vm = svm_sc->vm;
vcpustate = svm_get_vcpu(svm_sc, vcpu);
state = svm_get_vmcb_state(svm_sc, vcpu);
ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
vmexit = vm_exitinfo(vm, vcpu);
vlapic = vm_lapic(vm, vcpu);
/*
* Stash 'curcpu' on the stack as 'thiscpu'.
*
* The per-cpu data area is not accessible until MSR_GSBASE is restored
* after the #VMEXIT. Since VMRUN is executed inside a critical section
* 'curcpu' and 'thiscpu' are guaranteed to identical.
*/
thiscpu = curcpu;
gctx = svm_get_guest_regctx(svm_sc, vcpu);
vmcb_pa = svm_sc->vcpu[vcpu].vmcb_pa;
if (vcpustate->lastcpu != thiscpu) {
/*
* Force new ASID allocation by invalidating the generation.
*/
vcpustate->asid.gen = 0;
/*
* Invalidate the VMCB state cache by marking all fields dirty.
*/
svm_set_dirty(svm_sc, vcpu, 0xffffffff);
/*
* XXX
* Setting 'vcpustate->lastcpu' here is bit premature because
* we may return from this function without actually executing
* the VMRUN instruction. This could happen if a rendezvous
* or an AST is pending on the first time through the loop.
*
* This works for now but any new side-effects of vcpu
* migration should take this case into account.
*/
vcpustate->lastcpu = thiscpu;
vmm_stat_incr(vm, vcpu, VCPU_MIGRATIONS, 1);
}
svm_msr_guest_enter(svm_sc, vcpu);
/* Update Guest RIP */
state->rip = rip;
do {
/*
* Disable global interrupts to guarantee atomicity during
* loading of guest state. This includes not only the state
* loaded by the "vmrun" instruction but also software state
* maintained by the hypervisor: suspended and rendezvous
* state, NPT generation number, vlapic interrupts etc.
*/
disable_gintr();
if (vcpu_suspended(suspended_cookie)) {
enable_gintr();
vm_exit_suspended(vm, vcpu, state->rip);
break;
}
if (vcpu_rendezvous_pending(rend_cookie)) {
enable_gintr();
vm_exit_rendezvous(vm, vcpu, state->rip);
break;
}
/* We are asked to give the cpu by scheduler. */
if (curthread->td_flags & (TDF_ASTPENDING | TDF_NEEDRESCHED)) {
enable_gintr();
vm_exit_astpending(vm, vcpu, state->rip);
break;
}
svm_inj_interrupts(svm_sc, vcpu, vlapic);
/* Activate the nested pmap on 'thiscpu' */
CPU_SET_ATOMIC_ACQ(thiscpu, &pmap->pm_active);
/*
* Check the pmap generation and the ASID generation to
* ensure that the vcpu does not use stale TLB mappings.
*/
check_asid(svm_sc, vcpu, pmap, thiscpu);
ctrl->vmcb_clean = vmcb_clean & ~vcpustate->dirty;
vcpustate->dirty = 0;
VCPU_CTR1(vm, vcpu, "vmcb clean %#x", ctrl->vmcb_clean);
/* Launch Virtual Machine. */
VCPU_CTR1(vm, vcpu, "Resume execution at %#lx", state->rip);
svm_launch(vmcb_pa, gctx);
CPU_CLR_ATOMIC(thiscpu, &pmap->pm_active);
/*
* Restore MSR_GSBASE to point to the pcpu data area.
*
* Note that accesses done via PCPU_GET/PCPU_SET will work
* only after MSR_GSBASE is restored.
*
* Also note that we don't bother restoring MSR_KGSBASE
* since it is not used in the kernel and will be restored
* when the VMRUN ioctl returns to userspace.
*/
wrmsr(MSR_GSBASE, (uint64_t)&__pcpu[thiscpu]);
KASSERT(curcpu == thiscpu, ("thiscpu/curcpu (%u/%u) mismatch",
thiscpu, curcpu));
/*
* The host GDTR and IDTR is saved by VMRUN and restored
* automatically on #VMEXIT. However, the host TSS needs
* to be restored explicitly.
*/
restore_host_tss();
/* #VMEXIT disables interrupts so re-enable them here. */
enable_gintr();
/* Handle #VMEXIT and if required return to user space. */
handled = svm_vmexit(svm_sc, vcpu, vmexit);
} while (handled);
svm_msr_guest_exit(svm_sc, vcpu);
return (0);
}
static void
svm_vmcleanup(void *arg)
{
struct svm_softc *sc = arg;
free(sc, M_SVM);
}
static register_t *
swctx_regptr(struct svm_regctx *regctx, int reg)
{
switch (reg) {
case VM_REG_GUEST_RBX:
return (&regctx->sctx_rbx);
case VM_REG_GUEST_RCX:
return (&regctx->sctx_rcx);
case VM_REG_GUEST_RDX:
return (&regctx->sctx_rdx);
case VM_REG_GUEST_RDI:
return (&regctx->sctx_rdi);
case VM_REG_GUEST_RSI:
return (&regctx->sctx_rsi);
case VM_REG_GUEST_RBP:
return (&regctx->sctx_rbp);
case VM_REG_GUEST_R8:
return (&regctx->sctx_r8);
case VM_REG_GUEST_R9:
return (&regctx->sctx_r9);
case VM_REG_GUEST_R10:
return (&regctx->sctx_r10);
case VM_REG_GUEST_R11:
return (&regctx->sctx_r11);
case VM_REG_GUEST_R12:
return (&regctx->sctx_r12);
case VM_REG_GUEST_R13:
return (&regctx->sctx_r13);
case VM_REG_GUEST_R14:
return (&regctx->sctx_r14);
case VM_REG_GUEST_R15:
return (&regctx->sctx_r15);
default:
return (NULL);
}
}
static int
svm_getreg(void *arg, int vcpu, int ident, uint64_t *val)
{
struct svm_softc *svm_sc;
register_t *reg;
svm_sc = arg;
if (ident == VM_REG_GUEST_INTR_SHADOW) {
return (svm_get_intr_shadow(svm_sc, vcpu, val));
}
if (vmcb_read(svm_sc, vcpu, ident, val) == 0) {
return (0);
}
reg = swctx_regptr(svm_get_guest_regctx(svm_sc, vcpu), ident);
if (reg != NULL) {
*val = *reg;
return (0);
}
VCPU_CTR1(svm_sc->vm, vcpu, "svm_getreg: unknown register %#x", ident);
return (EINVAL);
}
static int
svm_setreg(void *arg, int vcpu, int ident, uint64_t val)
{
struct svm_softc *svm_sc;
register_t *reg;
svm_sc = arg;
if (ident == VM_REG_GUEST_INTR_SHADOW) {
return (svm_modify_intr_shadow(svm_sc, vcpu, val));
}
if (vmcb_write(svm_sc, vcpu, ident, val) == 0) {
return (0);
}
reg = swctx_regptr(svm_get_guest_regctx(svm_sc, vcpu), ident);
if (reg != NULL) {
*reg = val;
return (0);
}
/*
* XXX deal with CR3 and invalidate TLB entries tagged with the
* vcpu's ASID. This needs to be treated differently depending on
* whether 'running' is true/false.
*/
VCPU_CTR1(svm_sc->vm, vcpu, "svm_setreg: unknown register %#x", ident);
return (EINVAL);
}
static int
svm_setcap(void *arg, int vcpu, int type, int val)
{
struct svm_softc *sc;
int error;
sc = arg;
error = 0;
switch (type) {
case VM_CAP_HALT_EXIT:
svm_set_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_HLT, val);
break;
case VM_CAP_PAUSE_EXIT:
svm_set_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_PAUSE, val);
break;
case VM_CAP_UNRESTRICTED_GUEST:
/* Unrestricted guest execution cannot be disabled in SVM */
if (val == 0)
error = EINVAL;
break;
default:
error = ENOENT;
break;
}
return (error);
}
static int
svm_getcap(void *arg, int vcpu, int type, int *retval)
{
struct svm_softc *sc;
int error;
sc = arg;
error = 0;
switch (type) {
case VM_CAP_HALT_EXIT:
*retval = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_HLT);
break;
case VM_CAP_PAUSE_EXIT:
*retval = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
VMCB_INTCPT_PAUSE);
break;
case VM_CAP_UNRESTRICTED_GUEST:
*retval = 1; /* unrestricted guest is always enabled */
break;
default:
error = ENOENT;
break;
}
return (error);
}
static struct vlapic *
svm_vlapic_init(void *arg, int vcpuid)
{
struct svm_softc *svm_sc;
struct vlapic *vlapic;
svm_sc = arg;
vlapic = malloc(sizeof(struct vlapic), M_SVM_VLAPIC, M_WAITOK | M_ZERO);
vlapic->vm = svm_sc->vm;
vlapic->vcpuid = vcpuid;
vlapic->apic_page = (struct LAPIC *)&svm_sc->apic_page[vcpuid];
vlapic_init(vlapic);
return (vlapic);
}
static void
svm_vlapic_cleanup(void *arg, struct vlapic *vlapic)
{
vlapic_cleanup(vlapic);
free(vlapic, M_SVM_VLAPIC);
}
struct vmm_ops vmm_ops_amd = {
svm_init,
svm_cleanup,
svm_restore,
svm_vminit,
svm_vmrun,
svm_vmcleanup,
svm_getreg,
svm_setreg,
vmcb_getdesc,
vmcb_setdesc,
svm_getcap,
svm_setcap,
svm_npt_alloc,
svm_npt_free,
svm_vlapic_init,
svm_vlapic_cleanup
};
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