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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-28 19:00:26 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-28 19:00:26 +0200
commit3cd7cd8a62e6f4b81e8429db7afcb11cc155ea3c (patch)
treea41595f395ecd0be8a1396fd804cbdb7fdfb6207 /arch/x86
parente0152705e4630b4a6ae8eb716aa44ed5a90054ea (diff)
parent17179d0068b20413de2355f84c75a93740257e20 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "Two larger x86 series: - Redo incorrect fix for SEV/SMAP erratum - Windows 11 Hyper-V workaround Other x86 changes: - Various x86 cleanups - Re-enable access_tracking_perf_test - Fix for #GP handling on SVM - Fix for CPUID leaf 0Dh in KVM_GET_SUPPORTED_CPUID - Fix for ICEBP in interrupt shadow - Avoid false-positive RCU splat - Enable Enlightened MSR-Bitmap support for real ARM: - Correctly update the shadow register on exception injection when running in nVHE mode - Correctly use the mm_ops indirection when performing cache invalidation from the page-table walker - Restrict the vgic-v3 workaround for SEIS to the two known broken implementations Generic code changes: - Dead code cleanup" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (43 commits) KVM: eventfd: Fix false positive RCU usage warning KVM: nVMX: Allow VMREAD when Enlightened VMCS is in use KVM: nVMX: Implement evmcs_field_offset() suitable for handle_vmread() KVM: nVMX: Rename vmcs_to_field_offset{,_table} KVM: nVMX: eVMCS: Filter out VM_EXIT_SAVE_VMX_PREEMPTION_TIMER KVM: nVMX: Also filter MSR_IA32_VMX_TRUE_PINBASED_CTLS when eVMCS selftests: kvm: check dynamic bits against KVM_X86_XCOMP_GUEST_SUPP KVM: x86: add system attribute to retrieve full set of supported xsave states KVM: x86: Add a helper to retrieve userspace address from kvm_device_attr selftests: kvm: move vm_xsave_req_perm call to amx_test KVM: x86: Sync the states size with the XCR0/IA32_XSS at, any time KVM: x86: Update vCPU's runtime CPUID on write to MSR_IA32_XSS KVM: x86: Keep MSR_IA32_XSS unchanged for INIT KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2} KVM: nVMX: WARN on any attempt to allocate shadow VMCS for vmcs02 KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest KVM: x86: Check .flags in kvm_cpuid_check_equal() too KVM: x86: Forcibly leave nested virt when SMM state is toggled KVM: SVM: drop unnecessary code in svm_hv_vmcb_dirty_nested_enlightenments() KVM: SVM: hyper-v: Enable Enlightened MSR-Bitmap support for real ...
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/kvm_host.h5
-rw-r--r--arch/x86/include/uapi/asm/kvm.h3
-rw-r--r--arch/x86/kvm/cpuid.c90
-rw-r--r--arch/x86/kvm/lapic.c2
-rw-r--r--arch/x86/kvm/svm/nested.c9
-rw-r--r--arch/x86/kvm/svm/sev.c9
-rw-r--r--arch/x86/kvm/svm/svm.c177
-rw-r--r--arch/x86/kvm/svm/svm.h7
-rw-r--r--arch/x86/kvm/svm/svm_onhyperv.h12
-rw-r--r--arch/x86/kvm/vmx/capabilities.h1
-rw-r--r--arch/x86/kvm/vmx/evmcs.c4
-rw-r--r--arch/x86/kvm/vmx/evmcs.h48
-rw-r--r--arch/x86/kvm/vmx/nested.c82
-rw-r--r--arch/x86/kvm/vmx/vmcs12.c4
-rw-r--r--arch/x86/kvm/vmx/vmcs12.h6
-rw-r--r--arch/x86/kvm/vmx/vmx.c47
-rw-r--r--arch/x86/kvm/x86.c94
-rw-r--r--arch/x86/kvm/xen.c10
18 files changed, 422 insertions, 188 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1384517d7709..6e7c545bc7ee 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1483,7 +1483,8 @@ struct kvm_x86_ops {
int (*get_msr_feature)(struct kvm_msr_entry *entry);
- bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, void *insn, int insn_len);
+ bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len);
bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);
int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
@@ -1496,6 +1497,7 @@ struct kvm_x86_ops {
};
struct kvm_x86_nested_ops {
+ void (*leave_nested)(struct kvm_vcpu *vcpu);
int (*check_events)(struct kvm_vcpu *vcpu);
bool (*hv_timer_pending)(struct kvm_vcpu *vcpu);
void (*triple_fault)(struct kvm_vcpu *vcpu);
@@ -1861,7 +1863,6 @@ int kvm_cpu_has_extint(struct kvm_vcpu *v);
int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
-void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
unsigned long ipi_bitmap_high, u32 min,
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 2da3316bb559..bf6e96011dfe 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -452,6 +452,9 @@ struct kvm_sync_regs {
#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
+/* attributes for system fd (group 0) */
+#define KVM_X86_XCOMP_GUEST_SUPP 0
+
struct kvm_vmx_nested_state_data {
__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3902c28fb6cb..28be02adc669 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -133,6 +133,7 @@ static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2
orig = &vcpu->arch.cpuid_entries[i];
if (e2[i].function != orig->function ||
e2[i].index != orig->index ||
+ e2[i].flags != orig->flags ||
e2[i].eax != orig->eax || e2[i].ebx != orig->ebx ||
e2[i].ecx != orig->ecx || e2[i].edx != orig->edx)
return -EINVAL;
@@ -196,10 +197,26 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu)
vcpu->arch.pv_cpuid.features = best->eax;
}
+/*
+ * Calculate guest's supported XCR0 taking into account guest CPUID data and
+ * supported_xcr0 (comprised of host configuration and KVM_SUPPORTED_XCR0).
+ */
+static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ best = cpuid_entry2_find(entries, nent, 0xd, 0);
+ if (!best)
+ return 0;
+
+ return (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
+}
+
static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries,
int nent)
{
struct kvm_cpuid_entry2 *best;
+ u64 guest_supported_xcr0 = cpuid_get_supported_xcr0(entries, nent);
best = cpuid_entry2_find(entries, nent, 1, 0);
if (best) {
@@ -238,6 +255,21 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
vcpu->arch.ia32_misc_enable_msr &
MSR_IA32_MISC_ENABLE_MWAIT);
}
+
+ /*
+ * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate
+ * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's
+ * requested XCR0 value. The enclave's XFRM must be a subset of XCRO
+ * at the time of EENTER, thus adjust the allowed XFRM by the guest's
+ * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to
+ * '1' even on CPUs that don't support XSAVE.
+ */
+ best = cpuid_entry2_find(entries, nent, 0x12, 0x1);
+ if (best) {
+ best->ecx &= guest_supported_xcr0 & 0xffffffff;
+ best->edx &= guest_supported_xcr0 >> 32;
+ best->ecx |= XFEATURE_MASK_FPSSE;
+ }
}
void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
@@ -261,27 +293,8 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
kvm_apic_set_version(vcpu);
}
- best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
- if (!best)
- vcpu->arch.guest_supported_xcr0 = 0;
- else
- vcpu->arch.guest_supported_xcr0 =
- (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
-
- /*
- * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate
- * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's
- * requested XCR0 value. The enclave's XFRM must be a subset of XCRO
- * at the time of EENTER, thus adjust the allowed XFRM by the guest's
- * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to
- * '1' even on CPUs that don't support XSAVE.
- */
- best = kvm_find_cpuid_entry(vcpu, 0x12, 0x1);
- if (best) {
- best->ecx &= vcpu->arch.guest_supported_xcr0 & 0xffffffff;
- best->edx &= vcpu->arch.guest_supported_xcr0 >> 32;
- best->ecx |= XFEATURE_MASK_FPSSE;
- }
+ vcpu->arch.guest_supported_xcr0 =
+ cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
kvm_update_pv_runtime(vcpu);
@@ -346,8 +359,14 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
* KVM_SET_CPUID{,2} again. To support this legacy behavior, check
* whether the supplied CPUID data is equal to what's already set.
*/
- if (vcpu->arch.last_vmentry_cpu != -1)
- return kvm_cpuid_check_equal(vcpu, e2, nent);
+ if (vcpu->arch.last_vmentry_cpu != -1) {
+ r = kvm_cpuid_check_equal(vcpu, e2, nent);
+ if (r)
+ return r;
+
+ kvfree(e2);
+ return 0;
+ }
r = kvm_check_cpuid(vcpu, e2, nent);
if (r)
@@ -887,13 +906,14 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
}
break;
case 0xd: {
- u64 guest_perm = xstate_get_guest_group_perm();
+ u64 permitted_xcr0 = supported_xcr0 & xstate_get_guest_group_perm();
+ u64 permitted_xss = supported_xss;
- entry->eax &= supported_xcr0 & guest_perm;
- entry->ebx = xstate_required_size(supported_xcr0, false);
+ entry->eax &= permitted_xcr0;
+ entry->ebx = xstate_required_size(permitted_xcr0, false);
entry->ecx = entry->ebx;
- entry->edx &= (supported_xcr0 & guest_perm) >> 32;
- if (!supported_xcr0)
+ entry->edx &= permitted_xcr0 >> 32;
+ if (!permitted_xcr0)
break;
entry = do_host_cpuid(array, function, 1);
@@ -902,20 +922,20 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
cpuid_entry_override(entry, CPUID_D_1_EAX);
if (entry->eax & (F(XSAVES)|F(XSAVEC)))
- entry->ebx = xstate_required_size(supported_xcr0 | supported_xss,
+ entry->ebx = xstate_required_size(permitted_xcr0 | permitted_xss,
true);
else {
- WARN_ON_ONCE(supported_xss != 0);
+ WARN_ON_ONCE(permitted_xss != 0);
entry->ebx = 0;
}
- entry->ecx &= supported_xss;
- entry->edx &= supported_xss >> 32;
+ entry->ecx &= permitted_xss;
+ entry->edx &= permitted_xss >> 32;
for (i = 2; i < 64; ++i) {
bool s_state;
- if (supported_xcr0 & BIT_ULL(i))
+ if (permitted_xcr0 & BIT_ULL(i))
s_state = false;
- else if (supported_xss & BIT_ULL(i))
+ else if (permitted_xss & BIT_ULL(i))
s_state = true;
else
continue;
@@ -929,7 +949,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
* invalid sub-leafs. Only valid sub-leafs should
* reach this point, and they should have a non-zero
* save state size. Furthermore, check whether the
- * processor agrees with supported_xcr0/supported_xss
+ * processor agrees with permitted_xcr0/permitted_xss
* on whether this is an XCR0- or IA32_XSS-managed area.
*/
if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) {
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index baca9fa37a91..4662469240bc 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2629,7 +2629,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
kvm_apic_set_version(vcpu);
apic_update_ppr(apic);
- hrtimer_cancel(&apic->lapic_timer.timer);
+ cancel_apic_timer(apic);
apic->lapic_timer.expired_tscdeadline = 0;
apic_update_lvtt(apic);
apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cf206855ebf0..1218b5a342fc 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -983,9 +983,9 @@ void svm_free_nested(struct vcpu_svm *svm)
/*
* Forcibly leave nested mode in order to be able to reset the VCPU later on.
*/
-void svm_leave_nested(struct vcpu_svm *svm)
+void svm_leave_nested(struct kvm_vcpu *vcpu)
{
- struct kvm_vcpu *vcpu = &svm->vcpu;
+ struct vcpu_svm *svm = to_svm(vcpu);
if (is_guest_mode(vcpu)) {
svm->nested.nested_run_pending = 0;
@@ -1411,7 +1411,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
return -EINVAL;
if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE)) {
- svm_leave_nested(svm);
+ svm_leave_nested(vcpu);
svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));
return 0;
}
@@ -1478,7 +1478,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
*/
if (is_guest_mode(vcpu))
- svm_leave_nested(svm);
+ svm_leave_nested(vcpu);
else
svm->nested.vmcb02.ptr->save = svm->vmcb01.ptr->save;
@@ -1532,6 +1532,7 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
}
struct kvm_x86_nested_ops svm_nested_ops = {
+ .leave_nested = svm_leave_nested,
.check_events = svm_check_nested_events,
.triple_fault = nested_svm_triple_fault,
.get_nested_state_pages = svm_get_nested_state_pages,
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 6a22798eaaee..17b53457d866 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2100,8 +2100,13 @@ void __init sev_hardware_setup(void)
if (!sev_enabled || !npt_enabled)
goto out;
- /* Does the CPU support SEV? */
- if (!boot_cpu_has(X86_FEATURE_SEV))
+ /*
+ * SEV must obviously be supported in hardware. Sanity check that the
+ * CPU supports decode assists, which is mandatory for SEV guests to
+ * support instruction emulation.
+ */
+ if (!boot_cpu_has(X86_FEATURE_SEV) ||
+ WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)))
goto out;
/* Retrieve SEV CPUID information */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2c99b18d76c0..6d97629655e3 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -290,7 +290,7 @@ int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)
if ((old_efer & EFER_SVME) != (efer & EFER_SVME)) {
if (!(efer & EFER_SVME)) {
- svm_leave_nested(svm);
+ svm_leave_nested(vcpu);
svm_set_gif(svm, true);
/* #GP intercept is still needed for vmware backdoor */
if (!enable_vmware_backdoor)
@@ -312,7 +312,11 @@ int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)
return ret;
}
- if (svm_gp_erratum_intercept)
+ /*
+ * Never intercept #GP for SEV guests, KVM can't
+ * decrypt guest memory to workaround the erratum.
+ */
+ if (svm_gp_erratum_intercept && !sev_guest(vcpu->kvm))
set_exception_intercept(svm, GP_VECTOR);
}
}
@@ -1010,9 +1014,10 @@ static void init_vmcb(struct kvm_vcpu *vcpu)
* Guest access to VMware backdoor ports could legitimately
* trigger #GP because of TSS I/O permission bitmap.
* We intercept those #GP and allow access to them anyway
- * as VMware does.
+ * as VMware does. Don't intercept #GP for SEV guests as KVM can't
+ * decrypt guest memory to decode the faulting instruction.
*/
- if (enable_vmware_backdoor)
+ if (enable_vmware_backdoor && !sev_guest(vcpu->kvm))
set_exception_intercept(svm, GP_VECTOR);
svm_set_intercept(svm, INTERCEPT_INTR);
@@ -2091,10 +2096,6 @@ static int gp_interception(struct kvm_vcpu *vcpu)
if (error_code)
goto reinject;
- /* All SVM instructions expect page aligned RAX */
- if (svm->vmcb->save.rax & ~PAGE_MASK)
- goto reinject;
-
/* Decode the instruction for usage later */
if (x86_decode_emulated_instruction(vcpu, 0, NULL, 0) != EMULATION_OK)
goto reinject;
@@ -2112,8 +2113,13 @@ static int gp_interception(struct kvm_vcpu *vcpu)
if (!is_guest_mode(vcpu))
return kvm_emulate_instruction(vcpu,
EMULTYPE_VMWARE_GP | EMULTYPE_NO_DECODE);
- } else
+ } else {
+ /* All SVM instructions expect page aligned RAX */
+ if (svm->vmcb->save.rax & ~PAGE_MASK)
+ goto reinject;
+
return emulate_svm_instr(vcpu, opcode);
+ }
reinject:
kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
@@ -4252,79 +4258,140 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu)
}
}
-static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
+static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
{
bool smep, smap, is_user;
unsigned long cr4;
+ u64 error_code;
+
+ /* Emulation is always possible when KVM has access to all guest state. */
+ if (!sev_guest(vcpu->kvm))
+ return true;
+
+ /* #UD and #GP should never be intercepted for SEV guests. */
+ WARN_ON_ONCE(emul_type & (EMULTYPE_TRAP_UD |
+ EMULTYPE_TRAP_UD_FORCED |
+ EMULTYPE_VMWARE_GP));
/*
- * When the guest is an SEV-ES guest, emulation is not possible.
+ * Emulation is impossible for SEV-ES guests as KVM doesn't have access
+ * to guest register state.
*/
if (sev_es_guest(vcpu->kvm))
return false;
/*
+ * Emulation is possible if the instruction is already decoded, e.g.
+ * when completing I/O after returning from userspace.
+ */
+ if (emul_type & EMULTYPE_NO_DECODE)
+ return true;
+
+ /*
+ * Emulation is possible for SEV guests if and only if a prefilled
+ * buffer containing the bytes of the intercepted instruction is
+ * available. SEV guest memory is encrypted with a guest specific key
+ * and cannot be decrypted by KVM, i.e. KVM would read cyphertext and
+ * decode garbage.
+ *
+ * Inject #UD if KVM reached this point without an instruction buffer.
+ * In practice, this path should never be hit by a well-behaved guest,
+ * e.g. KVM doesn't intercept #UD or #GP for SEV guests, but this path
+ * is still theoretically reachable, e.g. via unaccelerated fault-like
+ * AVIC access, and needs to be handled by KVM to avoid putting the
+ * guest into an infinite loop. Injecting #UD is somewhat arbitrary,
+ * but its the least awful option given lack of insight into the guest.
+ */
+ if (unlikely(!insn)) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return false;
+ }
+
+ /*
+ * Emulate for SEV guests if the insn buffer is not empty. The buffer
+ * will be empty if the DecodeAssist microcode cannot fetch bytes for
+ * the faulting instruction because the code fetch itself faulted, e.g.
+ * the guest attempted to fetch from emulated MMIO or a guest page
+ * table used to translate CS:RIP resides in emulated MMIO.
+ */
+ if (likely(insn_len))
+ return true;
+
+ /*
* Detect and workaround Errata 1096 Fam_17h_00_0Fh.
*
* Errata:
- * When CPU raise #NPF on guest data access and vCPU CR4.SMAP=1, it is
- * possible that CPU microcode implementing DecodeAssist will fail
- * to read bytes of instruction which caused #NPF. In this case,
- * GuestIntrBytes field of the VMCB on a VMEXIT will incorrectly
- * return 0 instead of the correct guest instruction bytes.
- *
- * This happens because CPU microcode reading instruction bytes
- * uses a special opcode which attempts to read data using CPL=0
- * privileges. The microcode reads CS:RIP and if it hits a SMAP
- * fault, it gives up and returns no instruction bytes.
+ * When CPU raises #NPF on guest data access and vCPU CR4.SMAP=1, it is
+ * possible that CPU microcode implementing DecodeAssist will fail to
+ * read guest memory at CS:RIP and vmcb.GuestIntrBytes will incorrectly
+ * be '0'. This happens because microcode reads CS:RIP using a _data_
+ * loap uop with CPL=0 privileges. If the load hits a SMAP #PF, ucode
+ * gives up and does not fill the instruction bytes buffer.
*
- * Detection:
- * We reach here in case CPU supports DecodeAssist, raised #NPF and
- * returned 0 in GuestIntrBytes field of the VMCB.
- * First, errata can only be triggered in case vCPU CR4.SMAP=1.
- * Second, if vCPU CR4.SMEP=1, errata could only be triggered
- * in case vCPU CPL==3 (Because otherwise guest would have triggered
- * a SMEP fault instead of #NPF).
- * Otherwise, vCPU CR4.SMEP=0, errata could be triggered by any vCPU CPL.
- * As most guests enable SMAP if they have also enabled SMEP, use above
- * logic in order to attempt minimize false-positive of detecting errata
- * while still preserving all cases semantic correctness.
+ * As above, KVM reaches this point iff the VM is an SEV guest, the CPU
+ * supports DecodeAssist, a #NPF was raised, KVM's page fault handler
+ * triggered emulation (e.g. for MMIO), and the CPU returned 0 in the
+ * GuestIntrBytes field of the VMCB.
*
- * Workaround:
- * To determine what instruction the guest was executing, the hypervisor
- * will have to decode the instruction at the instruction pointer.
+ * This does _not_ mean that the erratum has been encountered, as the
+ * DecodeAssist will also fail if the load for CS:RIP hits a legitimate
+ * #PF, e.g. if the guest attempt to execute from emulated MMIO and
+ * encountered a reserved/not-present #PF.
*
- * In non SEV guest, hypervisor will be able to read the guest
- * memory to decode the instruction pointer when insn_len is zero
- * so we return true to indicate that decoding is possible.
+ * To hit the erratum, the following conditions must be true:
+ * 1. CR4.SMAP=1 (obviously).
+ * 2. CR4.SMEP=0 || CPL=3. If SMEP=1 and CPL<3, the erratum cannot
+ * have been hit as the guest would have encountered a SMEP
+ * violation #PF, not a #NPF.
+ * 3. The #NPF is not due to a code fetch, in which case failure to
+ * retrieve the instruction bytes is legitimate (see abvoe).
*
- * But in the SEV guest, the guest memory is encrypted with the
- * guest specific key and hypervisor will not be able to decode the
- * instruction pointer so we will not able to workaround it. Lets
- * print the error and request to kill the guest.
+ * In addition, don't apply the erratum workaround if the #NPF occurred
+ * while translating guest page tables (see below).
*/
- if (likely(!insn || insn_len))
- return true;
-
- /*
- * If RIP is invalid, go ahead with emulation which will cause an
- * internal error exit.
- */
- if (!kvm_vcpu_gfn_to_memslot(vcpu, kvm_rip_read(vcpu) >> PAGE_SHIFT))
- return true;
+ error_code = to_svm(vcpu)->vmcb->control.exit_info_1;
+ if (error_code & (PFERR_GUEST_PAGE_MASK | PFERR_FETCH_MASK))
+ goto resume_guest;
cr4 = kvm_read_cr4(vcpu);
smep = cr4 & X86_CR4_SMEP;
smap = cr4 & X86_CR4_SMAP;
is_user = svm_get_cpl(vcpu) == 3;
if (smap && (!smep || is_user)) {
- if (!sev_guest(vcpu->kvm))
- return true;
-
pr_err_ratelimited("KVM: SEV Guest triggered AMD Erratum 1096\n");
- kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
+
+ /*
+ * If the fault occurred in userspace, arbitrarily inject #GP
+ * to avoid killing the guest and to hopefully avoid confusing
+ * the guest kernel too much, e.g. injecting #PF would not be
+ * coherent with respect to the guest's page tables. Request
+ * triple fault if the fault occurred in the kernel as there's
+ * no fault that KVM can inject without confusing the guest.
+ * In practice, the triple fault is moot as no sane SEV kernel
+ * will execute from user memory while also running with SMAP=1.
+ */
+ if (is_user)
+ kvm_inject_gp(vcpu, 0);
+ else
+ kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
}
+resume_guest:
+ /*
+ * If the erratum was not hit, simply resume the guest and let it fault
+ * again. While awful, e.g. the vCPU may get stuck in an infinite loop
+ * if the fault is at CPL=0, it's the lesser of all evils. Exiting to
+ * userspace will kill the guest, and letting the emulator read garbage
+ * will yield random behavior and potentially corrupt the guest.
+ *
+ * Simply resuming the guest is technically not a violation of the SEV
+ * architecture. AMD's APM states that all code fetches and page table
+ * accesses for SEV guest are encrypted, regardless of the C-Bit. The
+ * APM also states that encrypted accesses to MMIO are "ignored", but
+ * doesn't explicitly define "ignored", i.e. doing nothing and letting
+ * the guest spin is technically "ignoring" the access.
+ */
return false;
}
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 47ef8f4a9358..73525353e424 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -304,11 +304,6 @@ static inline void vmcb_mark_all_clean(struct vmcb *vmcb)
& ~VMCB_ALWAYS_DIRTY_MASK;
}
-static inline bool vmcb_is_clean(struct vmcb *vmcb, int bit)
-{
- return (vmcb->control.clean & (1 << bit));
-}
-
static inline void vmcb_mark_dirty(struct vmcb *vmcb, int bit)
{
vmcb->control.clean &= ~(1 << bit);
@@ -525,7 +520,7 @@ static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
int enter_svm_guest_mode(struct kvm_vcpu *vcpu,
u64 vmcb_gpa, struct vmcb *vmcb12, bool from_vmrun);
-void svm_leave_nested(struct vcpu_svm *svm);
+void svm_leave_nested(struct kvm_vcpu *vcpu);
void svm_free_nested(struct vcpu_svm *svm);
int svm_allocate_nested(struct vcpu_svm *svm);
int nested_svm_vmrun(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index c53b8bf8d013..489ca56212c6 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -46,6 +46,9 @@ static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
if (npt_enabled &&
ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB)
hve->hv_enlightenments_control.enlightened_npt_tlb = 1;
+
+ if (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)
+ hve->hv_enlightenments_control.msr_bitmap = 1;
}
static inline void svm_hv_hardware_setup(void)
@@ -83,14 +86,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
struct hv_enlightenments *hve =
(struct hv_enlightenments *)vmcb->control.reserved_sw;
- /*
- * vmcb can be NULL if called during early vcpu init.
- * And its okay not to mark vmcb dirty during vcpu init
- * as we mark it dirty unconditionally towards end of vcpu
- * init phase.
- */
- if (vmcb_is_clean(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS) &&
- hve->hv_enlightenments_control.msr_bitmap)
+ if (hve->hv_enlightenments_control.msr_bitmap)
vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
}
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 959b59d13b5a..3f430e218375 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -54,7 +54,6 @@ struct nested_vmx_msrs {
struct vmcs_config {
int size;
- int order;
u32 basic_cap;
u32 revision_id;
u32 pin_based_exec_ctrl;
diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index ba6f99f584ac..87e3dc10edf4 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -12,8 +12,6 @@
DEFINE_STATIC_KEY_FALSE(enable_evmcs);
-#if IS_ENABLED(CONFIG_HYPERV)
-
#define EVMCS1_OFFSET(x) offsetof(struct hv_enlightened_vmcs, x)
#define EVMCS1_FIELD(number, name, clean_field)[ROL16(number, 6)] = \
{EVMCS1_OFFSET(name), clean_field}
@@ -296,6 +294,7 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
};
const unsigned int nr_evmcs_1_fields = ARRAY_SIZE(vmcs_field_to_evmcs_1);
+#if IS_ENABLED(CONFIG_HYPERV)
__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
{
vmcs_conf->pin_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_PINCTRL;
@@ -362,6 +361,7 @@ void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata)
case MSR_IA32_VMX_PROCBASED_CTLS2:
ctl_high &= ~EVMCS1_UNSUPPORTED_2NDEXEC;
break;
+ case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
case MSR_IA32_VMX_PINBASED_CTLS:
ctl_high &= ~EVMCS1_UNSUPPORTED_PINCTRL;
break;
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index 16731d2cf231..8d70f9aea94b 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -59,12 +59,12 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
SECONDARY_EXEC_SHADOW_VMCS | \
SECONDARY_EXEC_TSC_SCALING | \
SECONDARY_EXEC_PAUSE_LOOP_EXITING)
-#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
+#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL \
+ (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | \
+ VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
#define EVMCS1_UNSUPPORTED_VMFUNC (VMX_VMFUNC_EPTP_SWITCHING)
-#if IS_ENABLED(CONFIG_HYPERV)
-
struct evmcs_field {
u16 offset;
u16 clean_field;
@@ -73,26 +73,56 @@ struct evmcs_field {
extern const struct evmcs_field vmcs_field_to_evmcs_1[];
extern const unsigned int nr_evmcs_1_fields;
-static __always_inline int get_evmcs_offset(unsigned long field,
- u16 *clean_field)
+static __always_inline int evmcs_field_offset(unsigned long field,
+ u16 *clean_field)
{
unsigned int index = ROL16(field, 6);
const struct evmcs_field *evmcs_field;
- if (unlikely(index >= nr_evmcs_1_fields)) {
- WARN_ONCE(1, "KVM: accessing unsupported EVMCS field %lx\n",
- field);
+ if (unlikely(index >= nr_evmcs_1_fields))
return -ENOENT;
- }
evmcs_field = &vmcs_field_to_evmcs_1[index];
+ /*
+ * Use offset=0 to detect holes in eVMCS. This offset belongs to
+ * 'revision_id' but this field has no encoding and is supposed to
+ * be accessed directly.
+ */
+ if (unlikely(!evmcs_field->offset))
+ return -ENOENT;
+
if (clean_field)
*clean_field = evmcs_field->clean_field;
return evmcs_field->offset;
}
+static inline u64 evmcs_read_any(struct hv_enlightened_vmcs *evmcs,
+ unsigned long field, u16 offset)
+{
+ /*
+ * vmcs12_read_any() doesn't care whether the supplied structure
+ * is 'struct vmcs12' or 'struct hv_enlightened_vmcs' as it takes
+ * the exact offset of the required field, use it for convenience
+ * here.
+ */
+ return vmcs12_read_any((void *)evmcs, field, offset);
+}
+
+#if IS_ENABLED(CONFIG_HYPERV)
+
+static __always_inline int get_evmcs_offset(unsigned long field,
+ u16 *clean_field)
+{
+ int offset = evmcs_field_offset(field, clean_field);
+
+ WARN_ONCE(offset < 0, "KVM: accessing unsupported EVMCS field %lx\n",
+ field);
+
+ return offset;
+}
+
static __always_inline void evmcs_write64(unsigned long field, u64 value)
{
u16 clean_field;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f235f77cbc03..ba34e94049c7 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -7,6 +7,7 @@
#include <asm/mmu_context.h>
#include "cpuid.h"
+#include "evmcs.h"
#include "hyperv.h"
#include "mmu.h"
#include "nested.h"
@@ -4851,18 +4852,20 @@ static struct vmcs *alloc_shadow_vmcs(struct kvm_vcpu *vcpu)
struct loaded_vmcs *loaded_vmcs = vmx->loaded_vmcs;
/*
- * We should allocate a shadow vmcs for vmcs01 only when L1
- * executes VMXON and free it when L1 executes VMXOFF.
- * As it is invalid to execute VMXON twice, we shouldn't reach
- * here when vmcs01 already have an allocated shadow vmcs.
+ * KVM allocates a shadow VMCS only when L1 executes VMXON and frees it
+ * when L1 executes VMXOFF or the vCPU is forced out of nested
+ * operation. VMXON faults if the CPU is already post-VMXON, so it
+ * should be impossible to already have an allocated shadow VMCS. KVM
+ * doesn't support virtualization of VMCS shadowing, so vmcs01 should
+ * always be the loaded VMCS.
*/
- WARN_ON(loaded_vmcs == &vmx->vmcs01 && loaded_vmcs->shadow_vmcs);
+ if (WARN_ON(loaded_vmcs != &vmx->vmcs01 || loaded_vmcs->shadow_vmcs))
+ return loaded_vmcs->shadow_vmcs;
+
+ loaded_vmcs->shadow_vmcs = alloc_vmcs(true);
+ if (loaded_vmcs->shadow_vmcs)
+ vmcs_clear(loaded_vmcs->shadow_vmcs);
- if (!loaded_vmcs->shadow_vmcs) {
- loaded_vmcs->shadow_vmcs = alloc_vmcs(true);
- if (loaded_vmcs->shadow_vmcs)
- vmcs_clear(loaded_vmcs->shadow_vmcs);
- }
return loaded_vmcs->shadow_vmcs;
}
@@ -5099,27 +5102,49 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
if (!nested_vmx_check_permission(vcpu))
return 1;
- /*
- * In VMX non-root operation, when the VMCS-link pointer is INVALID_GPA,
- * any VMREAD sets the ALU flags for VMfailInvalid.
- */
- if (vmx->nested.current_vmptr == INVALID_GPA ||
- (is_guest_mode(vcpu) &&
- get_vmcs12(vcpu)->vmcs_link_pointer == INVALID_GPA))
- return nested_vmx_failInvalid(vcpu);
-
/* Decode instruction info and find the field to read */
field = kvm_register_read(vcpu, (((instr_info) >> 28) & 0xf));
- offset = vmcs_field_to_offset(field);
- if (offset < 0)
- return nested_vmx_fail(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
+ if (!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+ /*
+ * In VMX non-root operation, when the VMCS-link pointer is INVALID_GPA,
+ * any VMREAD sets the ALU flags for VMfailInvalid.
+ */
+ if (vmx->nested.current_vmptr == INVALID_GPA ||
+ (is_guest_mode(vcpu) &&
+ get_vmcs12(vcpu)->vmcs_link_pointer == INVALID_GPA))
+ return nested_vmx_failInvalid(vcpu);
- if (!is_guest_mode(vcpu) && is_vmcs12_ext_field(field))
- copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
+ offset = get_vmcs12_field_offset(field);
+ if (offset < 0)
+ return nested_vmx_fail(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
+
+ if (!is_guest_mode(vcpu) && is_vmcs12_ext_field(field))
+ copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
- /* Read the field, zero-extended to a u64 value */
- value = vmcs12_read_any(vmcs12, field, offset);
+ /* Read the field, zero-extended to a u64 value */
+ value = vmcs12_read_any(vmcs12, field, offset);
+ } else {
+ /*
+ * Hyper-V TLFS (as of 6.0b) explicitly states, that while an
+ * enlightened VMCS is active VMREAD/VMWRITE instructions are
+ * unsupported. Unfortunately, certain versions of Windows 11
+ * don't comply with this requirement which is not enforced in
+ * genuine Hyper-V. Allow VMREAD from an enlightened VMCS as a
+ * workaround, as misbehaving guests will panic on VM-Fail.
+ * Note, enlightened VMCS is incompatible with shadow VMCS so
+ * all VMREADs from L2 should go to L1.
+ */
+ if (WARN_ON_ONCE(is_guest_mode(vcpu)))
+ return nested_vmx_failInvalid(vcpu);
+
+ offset = evmcs_field_offset(field, NULL);
+ if (offset < 0)
+ return nested_vmx_fail(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
+
+ /* Read the field, zero-extended to a u64 value */
+ value = evmcs_read_any(vmx->nested.hv_evmcs, field, offset);
+ }
/*
* Now copy part of this value to register or memory, as requested.
@@ -5214,7 +5239,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
field = kvm_register_read(vcpu, (((instr_info) >> 28) & 0xf));
- offset = vmcs_field_to_offset(field);
+ offset = get_vmcs12_field_offset(field);
if (offset < 0)
return nested_vmx_fail(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
@@ -6462,7 +6487,7 @@ static u64 nested_vmx_calc_vmcs_enum_msr(void)
max_idx = 0;
for (i = 0; i < nr_vmcs12_fields; i++) {
/* The vmcs12 table is very, very sparsely populated. */
- if (!vmcs_field_to_offset_table[i])
+ if (!vmcs12_field_offsets[i])
continue;
idx = vmcs_field_index(VMCS12_IDX_TO_ENC(i));
@@ -6771,6 +6796,7 @@ __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *))
}
struct kvm_x86_nested_ops vmx_nested_ops = {
+ .leave_nested = vmx_leave_nested,
.check_events = vmx_check_nested_events,
.hv_timer_pending = nested_vmx_preemption_timer_pending,
.triple_fault = nested_vmx_triple_fault,
diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c
index cab6ba7a5005..2251b60920f8 100644
--- a/arch/x86/kvm/vmx/vmcs12.c
+++ b/arch/x86/kvm/vmx/vmcs12.c
@@ -8,7 +8,7 @@
FIELD(number, name), \
[ROL16(number##_HIGH, 6)] = VMCS12_OFFSET(name) + sizeof(u32)
-const unsigned short vmcs_field_to_offset_table[] = {
+const unsigned short vmcs12_field_offsets[] = {
FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id),
FIELD(POSTED_INTR_NV, posted_intr_nv),
FIELD(GUEST_ES_SELECTOR, guest_es_selector),
@@ -151,4 +151,4 @@ const unsigned short vmcs_field_to_offset_table[] = {
FIELD(HOST_RSP, host_rsp),
FIELD(HOST_RIP, host_rip),
};
-const unsigned int nr_vmcs12_fields = ARRAY_SIZE(vmcs_field_to_offset_table);
+const unsigned int nr_vmcs12_fields = ARRAY_SIZE(vmcs12_field_offsets);
diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h
index 2a45f026ee11..746129ddd5ae 100644
--- a/arch/x86/kvm/vmx/vmcs12.h
+++ b/arch/x86/kvm/vmx/vmcs12.h
@@ -361,10 +361,10 @@ static inline void vmx_check_vmcs12_offsets(void)
CHECK_OFFSET(guest_pml_index, 996);
}
-extern const unsigned short vmcs_field_to_offset_table[];
+extern const unsigned short vmcs12_field_offsets[];
extern const unsigned int nr_vmcs12_fields;
-static inline short vmcs_field_to_offset(unsigned long field)
+static inline short get_vmcs12_field_offset(unsigned long field)
{
unsigned short offset;
unsigned int index;
@@ -377,7 +377,7 @@ static inline short vmcs_field_to_offset(unsigned long field)
return -ENOENT;
index = array_index_nospec(index, nr_vmcs12_fields);
- offset = vmcs_field_to_offset_table[index];
+ offset = vmcs12_field_offsets[index];
if (offset == 0)
return -ENOENT;
return offset;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4ac676066d60..aca3ae2a02f3 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1487,11 +1487,12 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
return 0;
}
-static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
+static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
{
/*
* Emulation of instructions in SGX enclaves is impossible as RIP does
- * not point tthe failing instruction, and even if it did, the code
+ * not point at the failing instruction, and even if it did, the code
* stream is inaccessible. Inject #UD instead of exiting to userspace
* so that guest userspace can't DoS the guest simply by triggering
* emulation (enclaves are CPL3 only).
@@ -2603,7 +2604,6 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
return -EIO;
vmcs_conf->size = vmx_msr_high & 0x1fff;
- vmcs_conf->order = get_order(vmcs_conf->size);
vmcs_conf->basic_cap = vmx_msr_high & ~0x1fff;
vmcs_conf->revision_id = vmx_msr_low;
@@ -2628,7 +2628,7 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
struct page *pages;
struct vmcs *vmcs;
- pages = __alloc_pages_node(node, flags, vmcs_config.order);
+ pages = __alloc_pages_node(node, flags, 0);
if (!pages)
return NULL;
vmcs = page_address(pages);
@@ -2647,7 +2647,7 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
void free_vmcs(struct vmcs *vmcs)
{
- free_pages((unsigned long)vmcs, vmcs_config.order);
+ free_page((unsigned long)vmcs);
}
/*
@@ -4094,10 +4094,14 @@ void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
vmcs_write32(HOST_IA32_SYSENTER_CS, low32);
/*
- * If 32-bit syscall is enabled, vmx_vcpu_load_vcms rewrites
- * HOST_IA32_SYSENTER_ESP.
+ * SYSENTER is used for 32-bit system calls on either 32-bit or
+ * 64-bit kernels. It is always zero If neither is allowed, otherwise
+ * vmx_vcpu_load_vmcs loads it with the per-CPU entry stack (and may
+ * have already done so!).
*/
- vmcs_writel(HOST_IA32_SYSENTER_ESP, 0);
+ if (!IS_ENABLED(CONFIG_IA32_EMULATION) && !IS_ENABLED(CONFIG_X86_32))
+ vmcs_writel(HOST_IA32_SYSENTER_ESP, 0);
+
rdmsrl(MSR_IA32_SYSENTER_EIP, tmpl);
vmcs_writel(HOST_IA32_SYSENTER_EIP, tmpl); /* 22.2.3 */
@@ -4901,8 +4905,33 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
dr6 = vmx_get_exit_qual(vcpu);
if (!(vcpu->guest_debug &
(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) {
+ /*
+ * If the #DB was due to ICEBP, a.k.a. INT1, skip the
+ * instruction. ICEBP generates a trap-like #DB, but
+ * despite its interception control being tied to #DB,
+ * is an instruction intercept, i.e. the VM-Exit occurs
+ * on the ICEBP itself. Note, skipping ICEBP also
+ * clears STI and MOVSS blocking.
+ *
+ * For all other #DBs, set vmcs.PENDING_DBG_EXCEPTIONS.BS
+ * if single-step is enabled in RFLAGS and STI or MOVSS
+ * blocking is active, as the CPU doesn't set the bit
+ * on VM-Exit due to #DB interception. VM-Entry has a
+ * consistency check that a single-step #DB is pending
+ * in this scenario as the previous instruction cannot
+ * have toggled RFLAGS.TF 0=>1 (because STI and POP/MOV
+ * don't modify RFLAGS), therefore the one instruction
+ * delay when activating single-step breakpoints must
+ * have already expired. Note, the CPU sets/clears BS
+ * as appropriate for all other VM-Exits types.
+ */
if (is_icebp(intr_info))
WARN_ON(!skip_emulated_instruction(vcpu));
+ else if ((vmx_get_rflags(vcpu) & X86_EFLAGS_TF) &&
+ (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
+ (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS)))
+ vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
+ vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS) | DR6_BS);
kvm_queue_exception_p(vcpu, DB_VECTOR, dr6);
return 1;
@@ -5397,7 +5426,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
{
gpa_t gpa;
- if (!vmx_can_emulate_instruction(vcpu, NULL, 0))
+ if (!vmx_can_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))
return 1;
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9e43d756312f..74b53a16f38a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3535,6 +3535,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
if (data & ~supported_xss)
return 1;
vcpu->arch.ia32_xss = data;
+ kvm_update_cpuid_runtime(vcpu);
break;
case MSR_SMI_COUNT:
if (!msr_info->host_initiated)
@@ -4229,6 +4230,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SREGS2:
case KVM_CAP_EXIT_ON_EMULATION_FAILURE:
case KVM_CAP_VCPU_ATTRIBUTES:
+ case KVM_CAP_SYS_ATTRIBUTES:
r = 1;
break;
case KVM_CAP_EXIT_HYPERCALL:
@@ -4331,7 +4333,49 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
break;
}
return r;
+}
+
+static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr)
+{
+ void __user *uaddr = (void __user*)(unsigned long)attr->addr;
+ if ((u64)(unsigned long)uaddr != attr->addr)
+ return ERR_PTR(-EFAULT);
+ return uaddr;
+}
+
+static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr)
+{
+ u64 __user *uaddr = kvm_get_attr_addr(attr);
+
+ if (attr->group)
+ return -ENXIO;
+
+ if (IS_ERR(uaddr))
+ return PTR_ERR(uaddr);
+
+ switch (attr->attr) {
+ case KVM_X86_XCOMP_GUEST_SUPP:
+ if (put_user(supported_xcr0, uaddr))
+ return -EFAULT;
+ return 0;
+ default:
+ return -ENXIO;
+ break;
+ }
+}
+
+static int kvm_x86_dev_has_attr(struct kvm_device_attr *attr)
+{
+ if (attr->group)
+ return -ENXIO;
+
+ switch (attr->attr) {
+ case KVM_X86_XCOMP_GUEST_SUPP:
+ return 0;
+ default:
+ return -ENXIO;
+ }
}
long kvm_arch_dev_ioctl(struct file *filp,
@@ -4422,6 +4466,22 @@ long kvm_arch_dev_ioctl(struct file *filp,
case KVM_GET_SUPPORTED_HV_CPUID:
r = kvm_ioctl_get_supported_hv_cpuid(NULL, argp);
break;
+ case KVM_GET_DEVICE_ATTR: {
+ struct kvm_device_attr attr;
+ r = -EFAULT;
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ break;
+ r = kvm_x86_dev_get_attr(&attr);
+ break;
+ }
+ case KVM_HAS_DEVICE_ATTR: {
+ struct kvm_device_attr attr;
+ r = -EFAULT;
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ break;
+ r = kvm_x86_dev_has_attr(&attr);
+ break;
+ }
default:
r = -EINVAL;
break;
@@ -4860,8 +4920,10 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
vcpu->arch.apic->sipi_vector = events->sipi_vector;
if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
- if (!!(vcpu->arch.hflags & HF_SMM_MASK) != events->smi.smm)
+ if (!!(vcpu->arch.hflags & HF_SMM_MASK) != events->smi.smm) {
+ kvm_x86_ops.nested_ops->leave_nested(vcpu);
kvm_smm_changed(vcpu, events->smi.smm);
+ }
vcpu->arch.smi_pending = events->smi.pending;
@@ -5022,11 +5084,11 @@ static int kvm_arch_tsc_has_attr(struct kvm_vcpu *vcpu,
static int kvm_arch_tsc_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
- u64 __user *uaddr = (u64 __user *)(unsigned long)attr->addr;
+ u64 __user *uaddr = kvm_get_attr_addr(attr);
int r;
- if ((u64)(unsigned long)uaddr != attr->addr)
- return -EFAULT;
+ if (IS_ERR(uaddr))
+ return PTR_ERR(uaddr);
switch (attr->attr) {
case KVM_VCPU_TSC_OFFSET:
@@ -5045,12 +5107,12 @@ static int kvm_arch_tsc_get_attr(struct kvm_vcpu *vcpu,
static int kvm_arch_tsc_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
- u64 __user *uaddr = (u64 __user *)(unsigned long)attr->addr;
+ u64 __user *uaddr = kvm_get_attr_addr(attr);
struct kvm *kvm = vcpu->kvm;
int r;
- if ((u64)(unsigned long)uaddr != attr->addr)
- return -EFAULT;
+ if (IS_ERR(uaddr))
+ return PTR_ERR(uaddr);
switch (attr->attr) {
case KVM_VCPU_TSC_OFFSET: {
@@ -6810,6 +6872,13 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
}
EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
+static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
+{
+ return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,
+ insn, insn_len);
+}
+
int handle_ud(struct kvm_vcpu *vcpu)
{
static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
@@ -6817,7 +6886,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
char sig[5]; /* ud2; .ascii "kvm" */
struct x86_exception e;
- if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, NULL, 0)))
+ if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))
return 1;
if (force_emulation_prefix &&
@@ -8193,7 +8262,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
bool writeback = true;
bool write_fault_to_spt;
- if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, insn, insn_len)))
+ if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
return 1;
vcpu->arch.l1tf_flush_l1d = true;
@@ -9706,7 +9775,7 @@ void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
}
-void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
+static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
{
if (!lapic_in_kernel(vcpu))
return;
@@ -11209,7 +11278,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vcpu->arch.msr_misc_features_enables = 0;
- vcpu->arch.xcr0 = XFEATURE_MASK_FP;
+ __kvm_set_xcr(vcpu, 0, XFEATURE_MASK_FP);
+ __kvm_set_msr(vcpu, MSR_IA32_XSS, 0, true);
}
/* All GPRs except RDX (handled below) are zeroed on RESET/INIT. */
@@ -11226,8 +11296,6 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1, 0);
kvm_rdx_write(vcpu, cpuid_0x1 ? cpuid_0x1->eax : 0x600);
- vcpu->arch.ia32_xss = 0;
-
static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 0e3f7d6e9fd7..bad57535fad0 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -316,10 +316,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
"\tnotq %0\n"
"\t" LOCK_PREFIX "andq %0, %2\n"
"2:\n"
- "\t.section .fixup,\"ax\"\n"
- "3:\tjmp\t2b\n"
- "\t.previous\n"
- _ASM_EXTABLE_UA(1b, 3b)
+ _ASM_EXTABLE_UA(1b, 2b)
: "=r" (evtchn_pending_sel),
"+m" (vi->evtchn_pending_sel),
"+m" (v->arch.xen.evtchn_pending_sel)
@@ -335,10 +332,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
"\tnotl %0\n"
"\t" LOCK_PREFIX "andl %0, %2\n"
"2:\n"
- "\t.section .fixup,\"ax\"\n"
- "3:\tjmp\t2b\n"
- "\t.previous\n"
- _ASM_EXTABLE_UA(1b, 3b)
+ _ASM_EXTABLE_UA(1b, 2b)
: "=r" (evtchn_pending_sel32),
"+m" (vi->evtchn_pending_sel),
"+m" (v->arch.xen.evtchn_pending_sel)