summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/cpuid.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
-rw-r--r--arch/x86/kvm/cpuid.c128
1 files changed, 80 insertions, 48 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index de6d44e07e34..2796dde06302 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 +85,31 @@ 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;
+
+
+ /*
+ * Similarly, use the first matching entry if KVM is doing a
+ * lookup (as opposed to emulating CPUID) for a function that's
+ * architecturally defined as not having a significant index.
+ */
+ if (index == KVM_CPUID_INDEX_NOT_SIGNIFICANT) {
+ /*
+ * Direct lookups from KVM should not diverge from what
+ * KVM defines internally (the architectural behavior).
+ */
+ WARN_ON_ONCE(cpuid_function_is_indexed(function));
+ return e;
+ }
}
return NULL;
@@ -96,7 +126,8 @@ 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 +182,7 @@ 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 +208,8 @@ 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)
@@ -200,7 +232,7 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu)
/*
* Calculate guest's supported XCR0 taking into account guest CPUID data and
- * supported_xcr0 (comprised of host configuration and KVM_SUPPORTED_XCR0).
+ * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0).
*/
static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
{
@@ -210,7 +242,7 @@ static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
if (!best)
return 0;
- return (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
+ return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0;
}
static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries,
@@ -219,7 +251,7 @@ 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 +282,7 @@ 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 &
@@ -283,9 +315,8 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->arch.apic;
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;
@@ -295,10 +326,16 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
kvm_apic_set_version(vcpu);
}
- guest_supported_xcr0 =
+ vcpu->arch.guest_supported_xcr0 =
cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
- vcpu->arch.guest_fpu.fpstate->user_xfeatures = guest_supported_xcr0;
+ /*
+ * FP+SSE can always be saved/restored via KVM_{G,S}ET_XSAVE, even if
+ * XSAVE/XCRO are not exposed to the guest, and even if XSAVE isn't
+ * supported by the host.
+ */
+ vcpu->arch.guest_fpu.fpstate->user_xfeatures = vcpu->arch.guest_supported_xcr0 |
+ XFEATURE_MASK_FPSSE;
kvm_update_pv_runtime(vcpu);
@@ -325,10 +362,10 @@ 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:
@@ -865,10 +902,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->edx = 0;
}
break;
- case 9:
- break;
case 0xa: { /* Architectural Performance Monitoring */
- struct x86_pmu_capability cap;
union cpuid10_eax eax;
union cpuid10_edx edx;
@@ -877,30 +911,20 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
break;
}
- perf_get_x86_pmu_capability(&cap);
+ eax.split.version_id = kvm_pmu_cap.version;
+ eax.split.num_counters = kvm_pmu_cap.num_counters_gp;
+ eax.split.bit_width = kvm_pmu_cap.bit_width_gp;
+ eax.split.mask_length = kvm_pmu_cap.events_mask_len;
+ edx.split.num_counters_fixed = kvm_pmu_cap.num_counters_fixed;
+ edx.split.bit_width_fixed = kvm_pmu_cap.bit_width_fixed;
- /*
- * The guest architecture pmu is only supported if the architecture
- * pmu exists on the host and the module parameters allow it.
- */
- if (!cap.version || !enable_pmu)
- memset(&cap, 0, sizeof(cap));
-
- eax.split.version_id = min(cap.version, 2);
- eax.split.num_counters = cap.num_counters_gp;
- eax.split.bit_width = cap.bit_width_gp;
- eax.split.mask_length = cap.events_mask_len;
-
- edx.split.num_counters_fixed =
- min(cap.num_counters_fixed, KVM_PMC_MAX_FIXED);
- edx.split.bit_width_fixed = cap.bit_width_fixed;
- if (cap.version)
+ if (kvm_pmu_cap.version)
edx.split.anythread_deprecated = 1;
edx.split.reserved1 = 0;
edx.split.reserved2 = 0;
entry->eax = eax.full;
- entry->ebx = cap.events_mask;
+ entry->ebx = kvm_pmu_cap.events_mask;
entry->ecx = 0;
entry->edx = edx.full;
break;
@@ -923,8 +947,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
}
break;
case 0xd: {
- u64 permitted_xcr0 = supported_xcr0 & xstate_get_guest_group_perm();
- u64 permitted_xss = supported_xss;
+ u64 permitted_xcr0 = kvm_caps.supported_xcr0 & xstate_get_guest_group_perm();
+ u64 permitted_xss = kvm_caps.supported_xss;
entry->eax &= permitted_xcr0;
entry->ebx = xstate_required_size(permitted_xcr0, false);
@@ -1313,12 +1337,20 @@ out_free:
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);
/*
@@ -1355,7 +1387,7 @@ 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;
@@ -1364,11 +1396,11 @@ 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;
@@ -1386,7 +1418,7 @@ 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,
@@ -1396,7 +1428,7 @@ 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) {
@@ -1425,7 +1457,7 @@ 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;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-18 19:50:36 +0300