From: Jim Mattson jmattson@google.com
commit 7030d8530e533844e2f4b0e7476498afcd324634 upstream.
KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM actually supports. The following ranges of CPUID.80000008H are reserved and should be masked off: ECX[31:18] ECX[11:8]
In addition, the PerfTscSize field at ECX[17:16] should also be zero because KVM does not set the PERFTSC bit at CPUID.80000001H.ECX[27].
Fixes: 24c82e576b78 ("KVM: Sanitize cpuid") Signed-off-by: Jim Mattson jmattson@google.com Message-Id: 20220929225203.2234702-3-jmattson@google.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/cpuid.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -647,6 +647,7 @@ static inline int __do_cpuid_ent(struct g_phys_as = phys_as;
entry->eax = g_phys_as | (virt_as << 8); + entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8)); entry->edx = 0; /* * IBRS, IBPB and VIRT_SSBD aren't necessarily present in