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

[ Upstream commit aae2e72229cdb21f90df2dbe4244c977e5d3265b ]

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 <jmattson@google.com>
Message-Id: <20220922231854.249383-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b17c9b0..d85a080 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -718,8 +718,6 @@ 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 */
                struct x86_pmu_capability cap;
                union cpuid10_eax eax;