Commit bd791999 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Override host CPUID results with kvm_cpu_caps 



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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent d8577a4c

arch/x86/kvm/cpuid.c

+11 −14
Original line number Diff line number Diff line
@@ -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 */

arch/x86/kvm/cpuid.h

+3 −3
Original line number Diff line number Diff line
@@ -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,

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,

arch/x86/kvm/svm.c

+1 −2
Original line number Diff line number Diff line
@@ -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;

	}

}

arch/x86/kvm/vmx/vmx.c

+0 −12
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE