Commit 58b3d12c authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: add support for CPUID leaf 0x80000021 



CPUID leaf 0x80000021 defines some features (or lack of bugs) of AMD
processors.  Expose the ones that make sense via KVM_GET_SUPPORTED_CPUID.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent bf07be36

arch/x86/kvm/cpuid.c

+18 −1
Original line number Diff line number Diff line
@@ -1068,7 +1068,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) 
		entry->edx = 0;

		break;

	case 0x80000000:

		entry->eax = min(entry->eax, 0x8000001f);

		entry->eax = min(entry->eax, 0x80000021);

		break;

	case 0x80000001:

		cpuid_entry_override(entry, CPUID_8000_0001_EDX);
@@ -1139,6 +1139,23 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) 
			entry->ebx &= ~GENMASK(11, 6);

		}

		break;

	case 0x80000020:

		entry->eax = entry->ebx = entry->ecx = entry->edx = 0;

		break;

	case 0x80000021:

		entry->ebx = entry->ecx = entry->edx = 0;

		/*

		 * Pass down these bits:

		 *    EAX      0      NNDBP, Processor ignores nested data breakpoints

		 *    EAX      2      LAS, LFENCE always serializing

		 *    EAX      6      NSCB, Null selector clear base

		 *

		 * Other defined bits are for MSRs that KVM does not expose:

		 *   EAX      3      SPCL, SMM page configuration lock

		 *   EAX      13     PCMSR, Prefetch control MSR

		 */

		entry->eax &= BIT(0) | BIT(2) | BIT(6);

		break;

	/*Add support for Centaur's CPUID instruction*/

	case 0xC0000000:

		/*Just support up to 0xC0000004 now*/