[PATCH 5.15 70/83] KVM: x86: Hide IA32_PLATFORM_DCA_CAP[31:0] from the guest

Greg Kroah-Hartman
2022-10-03T07:30:28Z

From: Jim Mattson <jmattson@google.com>

[ 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>
---
arch/x86/kvm/cpuid.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b17c9b00669e..d85a0808a446 100644
--- 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;
--
2.35.1