Commit af8e2ccf authored by Takahiro Itazuri's avatar Takahiro Itazuri Committed by Sean Christopherson
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KVM: x86: Advertise host CPUID 0x80000005 in KVM_GET_SUPPORTED_CPUID 



Advertise CPUID 0x80000005 (L1 cache and TLB info) to userspace so that
VMMs that reflect KVM_GET_SUPPORTED_CPUID into KVM_SET_CPUID2 will
enumerate sane cache/TLB information to the guest.

CPUID 0x80000006 (L2 cache and TLB and L3 cache info) has been returned
since commit 43d05de2 ("KVM: pass through CPUID(0x80000006)").
Enumerating both 0x80000005 and 0x80000006 with KVM_GET_SUPPORTED_CPUID
is better than reporting one or the other, and 0x80000005 could be helpful
for VMM to pass it to KVM_SET_CPUID{,2} for the same reason with
0x80000006.

Signed-off-by: default avatarTakahiro Itazuri <itazur@amazon.com>
Link: https://lore.kernel.org/all/ZK7NmfKI9xur%2FMop@google.com
Link: https://lore.kernel.org/r/20230712183136.85561-1-itazur@amazon.com


[sean: add link, massage changelog]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 7f717f54

arch/x86/kvm/cpuid.c

+3 −0
Original line number Diff line number Diff line
@@ -1151,6 +1151,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) 
		cpuid_entry_override(entry, CPUID_8000_0001_EDX);

		cpuid_entry_override(entry, CPUID_8000_0001_ECX);

		break;

	case 0x80000005:

		/*  Pass host L1 cache and TLB info. */

		break;

	case 0x80000006:

		/* Drop reserved bits, pass host L2 cache and TLB info. */

		entry->edx &= ~GENMASK(17, 16);