Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
v2: Rebased to kvm/queue.
v1: https://lore.kernel.org/all/20211022002006.1425701-1-seanjc@xxxxxxxxxx
arch/x86/kvm/cpuid.c | 71 ++++++++++++++++++++++++++----------
arch/x86/kvm/cpuid.h | 16 ++++----
arch/x86/kvm/hyperv.c | 8 ++--
arch/x86/kvm/svm/svm.c | 2 +-
arch/x86/kvm/vmx/pmu_intel.c | 4 +-
arch/x86/kvm/vmx/sgx.c | 8 ++--
arch/x86/kvm/vmx/vmx.c | 6 +--
arch/x86/kvm/x86.c | 2 +-
8 files changed, 75 insertions(+), 42 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index d47222ab8e6e..10247528b59b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -67,9 +67,17 @@ u32 xstate_required_size(u64 xstate_bv, bool compacted)
#define F feature_bit
#define SF(name) (boot_cpu_has(X86_FEATURE_##name) ? F(name) : 0)
+/*
+ * Magic value used by KVM when querying userspace-provided CPUID entries and
+ * doesn't care about the CPIUD index because the index of the function in
+ * question is not significant. Note, this magic value must have at least one
+ * bit set in bits[63:32] and must be consumed as a u64 by cpuid_entry2_find()
+ * to avoid false positives when processing guest CPUID input.
+ */
+#define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull
static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
- struct kvm_cpuid_entry2 *entries, int nent, u32 function, u32 index)
+ struct kvm_cpuid_entry2 *entries, int nent, u32 function, u64 index)
{
struct kvm_cpuid_entry2 *e;
int i;
@@ -77,9 +85,22 @@ static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
for (i = 0; i < nent; i++) {
e = &entries[i];
- if (e->function == function &&
- (!(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) || e->index == index))
+ if (e->function != function)
+ continue;
+
+ /*
+ * If the index isn't significant, use the first entry with a
+ * matching function. It's userspace's responsibilty to not
+ * provide "duplicate" entries in all cases.
+ */
+ if (!(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) || e->index == index)
return e;
+
+ /*
+ * Function matches and index is significant; not specifying an
+ * exact index in this case is a KVM bug.
+ */
+ WARN_ON_ONCE(index == KVM_CPUID_INDEX_NOT_SIGNIFICANT);
}
return NULL;
@@ -96,7 +117,8 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu,
* The existing code assumes virtual address is 48-bit or 57-bit in the
* canonical address checks; exit if it is ever changed.
*/
- best = cpuid_entry2_find(entries, nent, 0x80000008, 0);
+ best = cpuid_entry2_find(entries, nent, 0x80000008,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
if (best) {
int vaddr_bits = (best->eax & 0xff00) >> 8;
@@ -151,7 +173,7 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
vcpu->arch.kvm_cpuid_base = 0;
for_each_possible_hypervisor_cpuid_base(function) {
- entry = kvm_find_cpuid_entry(vcpu, function, 0);
+ entry = kvm_find_cpuid_entry(vcpu, function);
if (entry) {
u32 signature[3];
@@ -177,7 +199,8 @@ static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *v
if (!base)
return NULL;
- return cpuid_entry2_find(entries, nent, base | KVM_CPUID_FEATURES, 0);
+ return cpuid_entry2_find(entries, nent, base | KVM_CPUID_FEATURES,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
}
static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu)
@@ -219,7 +242,7 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
struct kvm_cpuid_entry2 *best;
u64 guest_supported_xcr0 = cpuid_get_supported_xcr0(entries, nent);
- best = cpuid_entry2_find(entries, nent, 1, 0);
+ best = cpuid_entry2_find(entries, nent, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
if (best) {
/* Update OSXSAVE bit */
if (boot_cpu_has(X86_FEATURE_XSAVE))
@@ -250,7 +273,7 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
- best = cpuid_entry2_find(entries, nent, 0x1, 0);
+ best = cpuid_entry2_find(entries, nent, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
if (best)
cpuid_entry_change(best, X86_FEATURE_MWAIT,
vcpu->arch.ia32_misc_enable_msr &
@@ -285,7 +308,7 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
struct kvm_cpuid_entry2 *best;
u64 guest_supported_xcr0;
- best = kvm_find_cpuid_entry(vcpu, 1, 0);
+ best = kvm_find_cpuid_entry(vcpu, 1);
if (best && apic) {
if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
apic->lapic_timer.timer_mode_mask = 3 << 17;
@@ -325,10 +348,10 @@ int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x80000000);
if (!best || best->eax < 0x80000008)
goto not_found;
- best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x80000008);
if (best)
return best->eax & 0xff;
not_found:
@@ -1302,12 +1325,20 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
return r;
}
-struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
- u32 function, u32 index)
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
+ u32 function, u32 index)
{
return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
function, index);
}
+EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry_index);
+
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
+ u32 function)
+{
+ return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
+ function, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+}
EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
/*
@@ -1344,7 +1375,7 @@ get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index)
struct kvm_cpuid_entry2 *basic, *class;
u32 function = *fn_ptr;
- basic = kvm_find_cpuid_entry(vcpu, 0, 0);
+ basic = kvm_find_cpuid_entry(vcpu, 0);
if (!basic)
return NULL;
@@ -1353,11 +1384,11 @@ get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index)
return NULL;
if (function >= 0x40000000 && function <= 0x4fffffff)
- class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00, 0);
+ class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00);
else if (function >= 0xc0000000)
- class = kvm_find_cpuid_entry(vcpu, 0xc0000000, 0);
+ class = kvm_find_cpuid_entry(vcpu, 0xc0000000);
else
- class = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
+ class = kvm_find_cpuid_entry(vcpu, function & 0x80000000);
if (class && function <= class->eax)
return NULL;
@@ -1375,7 +1406,7 @@ get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index)
* the effective CPUID entry is the max basic leaf. Note, the index of
* the original requested leaf is observed!
*/
- return kvm_find_cpuid_entry(vcpu, basic->eax, index);
+ return kvm_find_cpuid_entry_index(vcpu, basic->eax, index);
}
bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
@@ -1385,7 +1416,7 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
struct kvm_cpuid_entry2 *entry;
bool exact, used_max_basic = false;
- entry = kvm_find_cpuid_entry(vcpu, function, index);
+ entry = kvm_find_cpuid_entry_index(vcpu, function, index);
exact = !!entry;
if (!entry && !exact_only) {
@@ -1414,7 +1445,7 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
* exists. EDX can be copied from any existing index.
*/
if (function == 0xb || function == 0x1f) {
- entry = kvm_find_cpuid_entry(vcpu, function, 1);
+ entry = kvm_find_cpuid_entry_index(vcpu, function, 1);
if (entry) {
*ecx = index & 0xff;
*edx = entry->edx;
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index ac72aabba981..b1658c0de847 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -13,8 +13,10 @@ void kvm_set_cpu_caps(void);
void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
void kvm_update_pv_runtime(struct kvm_vcpu *vcpu);
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
+ u32 function, u32 index);
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
- u32 function, u32 index);
+ u32 function);
int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries,
unsigned int type);
@@ -76,7 +78,7 @@ static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,
const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
struct kvm_cpuid_entry2 *entry;
- entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
+ entry = kvm_find_cpuid_entry_index(vcpu, cpuid.function, cpuid.index);
if (!entry)
return NULL;
@@ -109,7 +111,7 @@ static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0);
return best &&
(is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
@@ -119,7 +121,7 @@ static inline bool guest_cpuid_is_intel(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0);
return best && is_guest_vendor_intel(best->ebx, best->ecx, best->edx);
}
@@ -127,7 +129,7 @@ static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x1);
if (!best)
return -1;
@@ -138,7 +140,7 @@ static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x1);
if (!best)
return -1;
@@ -154,7 +156,7 @@ static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
- best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x1);
if (!best)
return -1;
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index e2e95a6fccfd..ed804447589c 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1992,7 +1992,7 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
struct kvm_cpuid_entry2 *entry;
struct kvm_vcpu_hv *hv_vcpu;
- entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0);
+ entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE);
if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) {
vcpu->arch.hyperv_enabled = true;
} else {
@@ -2005,7 +2005,7 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
hv_vcpu = to_hv_vcpu(vcpu);
- entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES, 0);
+ entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
if (entry) {
hv_vcpu->cpuid_cache.features_eax = entry->eax;
hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
@@ -2016,7 +2016,7 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
hv_vcpu->cpuid_cache.features_edx = 0;
}
- entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0);
+ entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
if (entry) {
hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
@@ -2025,7 +2025,7 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
hv_vcpu->cpuid_cache.enlightenments_ebx = 0;
}
- entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, 0);
+ entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
if (entry)
hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
else
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 37ce061dfc76..d2fa008b04ad 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4193,7 +4193,7 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
/* For sev guests, the memory encryption bit is not reserved in CR3. */
if (sev_guest(vcpu->kvm)) {
- best = kvm_find_cpuid_entry(vcpu, 0x8000001F, 0);
+ best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
if (best)
vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
}
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 53ccba896e77..4bc098fbec31 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -531,7 +531,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->pebs_enable_mask = ~0ull;
pmu->pebs_data_cfg_mask = ~0ull;
- entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
+ entry = kvm_find_cpuid_entry(vcpu, 0xa);
if (!entry || !vcpu->kvm->arch.enable_pmu)
return;
eax.full = entry->eax;
@@ -577,7 +577,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->global_ovf_ctrl_mask &=
~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI;
- entry = kvm_find_cpuid_entry(vcpu, 7, 0);
+ entry = kvm_find_cpuid_entry_index(vcpu, 7, 0);
if (entry &&
(boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
(entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM))) {
diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c
index 35e7ec91ae86..d1cc7244bede 100644
--- a/arch/x86/kvm/vmx/sgx.c
+++ b/arch/x86/kvm/vmx/sgx.c
@@ -148,8 +148,8 @@ static int __handle_encls_ecreate(struct kvm_vcpu *vcpu,
u8 max_size_log2;
int trapnr, ret;
- sgx_12_0 = kvm_find_cpuid_entry(vcpu, 0x12, 0);
- sgx_12_1 = kvm_find_cpuid_entry(vcpu, 0x12, 1);
+ sgx_12_0 = kvm_find_cpuid_entry_index(vcpu, 0x12, 0);
+ sgx_12_1 = kvm_find_cpuid_entry_index(vcpu, 0x12, 1);
if (!sgx_12_0 || !sgx_12_1) {
kvm_prepare_emulation_failure_exit(vcpu);
return 0;
@@ -431,7 +431,7 @@ static bool sgx_intercept_encls_ecreate(struct kvm_vcpu *vcpu)
if (!vcpu->kvm->arch.sgx_provisioning_allowed)
return true;
- guest_cpuid = kvm_find_cpuid_entry(vcpu, 0x12, 0);
+ guest_cpuid = kvm_find_cpuid_entry_index(vcpu, 0x12, 0);
if (!guest_cpuid)
return true;
@@ -439,7 +439,7 @@ static bool sgx_intercept_encls_ecreate(struct kvm_vcpu *vcpu)
if (guest_cpuid->ebx != ebx || guest_cpuid->edx != edx)
return true;
- guest_cpuid = kvm_find_cpuid_entry(vcpu, 0x12, 1);
+ guest_cpuid = kvm_find_cpuid_entry_index(vcpu, 0x12, 1);
if (!guest_cpuid)
return true;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c30115b9cb33..74ca64e97643 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7428,7 +7428,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
vmx->nested.msrs.cr4_fixed1 |= (_cr4_mask); \
} while (0)
- entry = kvm_find_cpuid_entry(vcpu, 0x1, 0);
+ entry = kvm_find_cpuid_entry(vcpu, 0x1);
cr4_fixed1_update(X86_CR4_VME, edx, feature_bit(VME));
cr4_fixed1_update(X86_CR4_PVI, edx, feature_bit(VME));
cr4_fixed1_update(X86_CR4_TSD, edx, feature_bit(TSC));
@@ -7444,7 +7444,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
cr4_fixed1_update(X86_CR4_PCIDE, ecx, feature_bit(PCID));
cr4_fixed1_update(X86_CR4_OSXSAVE, ecx, feature_bit(XSAVE));
- entry = kvm_find_cpuid_entry(vcpu, 0x7, 0);
+ entry = kvm_find_cpuid_entry_index(vcpu, 0x7, 0);
cr4_fixed1_update(X86_CR4_FSGSBASE, ebx, feature_bit(FSGSBASE));
cr4_fixed1_update(X86_CR4_SMEP, ebx, feature_bit(SMEP));
cr4_fixed1_update(X86_CR4_SMAP, ebx, feature_bit(SMAP));
@@ -7479,7 +7479,7 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
int i;
for (i = 0; i < PT_CPUID_LEAVES; i++) {
- best = kvm_find_cpuid_entry(vcpu, 0x14, i);
+ best = kvm_find_cpuid_entry_index(vcpu, 0x14, i);
if (!best)
return;
vmx->pt_desc.caps[CPUID_EAX + i*PT_CPUID_REGS_NUM] = best->eax;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 567d13405445..329875d2ccf2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11731,7 +11731,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
* i.e. it's impossible for kvm_find_cpuid_entry() to find a valid entry
* on RESET. But, go through the motions in case that's ever remedied.
*/
- cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1, 0);
+ cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1);
kvm_rdx_write(vcpu, cpuid_0x1 ? cpuid_0x1->eax : 0x600);
static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
base-commit: b9b71f43683ae9d76b0989249607bbe8c9eb6c5c
