KVM: x86: Hide IA32_PLATFORM_DCA_CAP[31:0] from the guest

The only thing reported by CPUID.9 is the value of
IA32_PLATFORM_DCA_CAP[31:0] in EAX. This MSR doesn't even exist in the
guest, since CPUID.1:ECX.DCA[bit 18] is clear in the guest.

Clear CPUID.9 in KVM_GET_SUPPORTED_CPUID.

Fixes: 24c82e576b78 ("KVM: Sanitize cpuid")
Signed-off-by: Jim Mattson <[email protected]>
Message-Id: <20220922231854[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 4c1c2c06e96bb261ee0884adf192f06e231c0c78..2796dde06302a901a2dba41df1e7bb64d04992c9 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -902,8 +902,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
                        entry->edx = 0;
                }
                break;
-       case 9:
-               break;
        case 0xa: { /* Architectural Performance Monitoring */
                union cpuid10_eax eax;
                union cpuid10_edx edx;