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KVM: x86: Advertise host CPUID 0x80000005 in KVM_GET_SUPPORTED_CPUID

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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 43d05de2be ("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: Takahiro 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: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Takahiro Itazuri 2023-07-12 19:31:36 +01:00 committed by Sean Christopherson
parent 7f717f5484
commit af8e2ccfa6
1 changed files with 3 additions and 0 deletions
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3
arch/x86/kvm/cpuid.c
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@ -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);