summaryrefslogtreecommitdiffstats
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.c90
1 files changed, 55 insertions, 35 deletions
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)) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-23 13:40:39 +0000