From: Jim Mattson Date: Thu, 29 Sep 2022 22:52:00 +0000 (-0700) Subject: KVM: x86: Mask off reserved bits in CPUID.80000008H X-Git-Tag: v5.15.79~149 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=006366b96c16090c9b73e8930b8dba0251658d83;p=platform%2Fkernel%2Flinux-rpi.git KVM: x86: Mask off reserved bits in CPUID.80000008H 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 Message-Id: <20220929225203.2234702-3-jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 6ca34db..478721a 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -937,6 +937,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) g_phys_as = phys_as; entry->eax = g_phys_as | (virt_as << 8); + entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8)); entry->edx = 0; cpuid_entry_override(entry, CPUID_8000_0008_EBX); break;