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KVM: x86: Override host CPUID results with kvm_cpu_caps

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Override CPUID entries with kvm_cpu_caps during KVM_GET_SUPPORTED_CPUID
instead of masking the host CPUID result, which is redundant now that
the host CPUID is incorporated into kvm_cpu_caps at runtime.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-03-02 15:56:53 -08:00 committed by Paolo Bonzini
parent d8577a4c23
commit bd79199990
4 changed files with 15 additions and 31 deletions
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25
arch/x86/kvm/cpuid.c
View File

@ -485,8 +485,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0x1fU);
break;
case 1:
cpuid_entry_mask(entry, CPUID_1_EDX);
cpuid_entry_mask(entry, CPUID_1_ECX);
cpuid_entry_override(entry, CPUID_1_EDX);
cpuid_entry_override(entry, CPUID_1_ECX);
/* we support x2apic emulation even if host does not support
* it since we emulate x2apic in software */
cpuid_entry_set(entry, X86_FEATURE_X2APIC);
@ -531,9 +531,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
/* function 7 has additional index. */
case 7:
entry->eax = min(entry->eax, 1u);
cpuid_entry_mask(entry, CPUID_7_0_EBX);
cpuid_entry_mask(entry, CPUID_7_ECX);
cpuid_entry_mask(entry, CPUID_7_EDX);
cpuid_entry_override(entry, CPUID_7_0_EBX);
cpuid_entry_override(entry, CPUID_7_ECX);
cpuid_entry_override(entry, CPUID_7_EDX);
/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST);
@ -552,7 +552,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
if (!entry)
goto out;
cpuid_entry_mask(entry, CPUID_7_1_EAX);
cpuid_entry_override(entry, CPUID_7_1_EAX);
entry->ebx = 0;
entry->ecx = 0;
entry->edx = 0;
@ -618,7 +618,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
if (!entry)
goto out;
cpuid_entry_mask(entry, CPUID_D_1_EAX);
cpuid_entry_override(entry, CPUID_D_1_EAX);
if (entry->eax & (F(XSAVES)|F(XSAVEC)))
entry->ebx = xstate_required_size(supported_xcr0, true);
else
@ -697,11 +697,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0x8000001f);
break;
case 0x80000001:
cpuid_entry_mask(entry, CPUID_8000_0001_EDX);
/* Add it manually because it may not be in host CPUID. */
if (!tdp_enabled)
cpuid_entry_set(entry, X86_FEATURE_GBPAGES);
cpuid_entry_mask(entry, CPUID_8000_0001_ECX);
cpuid_entry_override(entry, CPUID_8000_0001_EDX);
cpuid_entry_override(entry, CPUID_8000_0001_ECX);
break;
case 0x80000007: /* Advanced power management */
/* invariant TSC is CPUID.80000007H:EDX[8] */
@ -719,7 +716,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
g_phys_as = phys_as;
entry->eax = g_phys_as | (virt_as << 8);
entry->edx = 0;
cpuid_entry_mask(entry, CPUID_8000_0008_EBX);
cpuid_entry_override(entry, CPUID_8000_0008_EBX);
/*
* AMD has separate bits for each SPEC_CTRL bit.
* arch/x86/kernel/cpu/bugs.c is kind enough to
@ -761,7 +758,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = min(entry->eax, 0xC0000004);
break;
case 0xC0000001:
cpuid_entry_mask(entry, CPUID_C000_0001_EDX);
cpuid_entry_override(entry, CPUID_C000_0001_EDX);
break;
case 3: /* Processor serial number */
case 5: /* MONITOR/MWAIT */

6
arch/x86/kvm/cpuid.h
View File

@ -170,13 +170,13 @@ static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
*reg &= ~__feature_bit(x86_feature);
}
static __always_inline void cpuid_entry_mask(struct kvm_cpuid_entry2 *entry,
enum cpuid_leafs leaf)
static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
enum cpuid_leafs leaf)
{
u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
*reg &= kvm_cpu_caps[leaf];
*reg = kvm_cpu_caps[leaf];
}
static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,

3
arch/x86/kvm/svm.c
View File

@ -6072,8 +6072,7 @@ static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper
ASID emulation to nested SVM */
entry->ecx = 0; /* Reserved */
/* Note, 0x8000000A.EDX is managed via kvm_cpu_caps. */;
cpuid_entry_mask(entry, CPUID_8000_000A_EDX);
cpuid_entry_override(entry, CPUID_8000_000A_EDX);
break;
}
}

12
arch/x86/kvm/vmx/vmx.c
View File

@ -7130,18 +7130,6 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
*/
static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
{
switch (entry->function) {
case 0x7:
/*
* UMIP needs to be manually set even though vmx_set_cpu_caps()
* also sets UMIP since do_host_cpuid() will drop it.
*/
if (vmx_umip_emulated())
cpuid_entry_set(entry, X86_FEATURE_UMIP);
break;
default:
break;
}
}
static __init void vmx_set_cpu_caps(void)