Commit c5b7da51 authored by Jim Mattson's avatar Jim Mattson Committed by Lipeng Sang
Browse files

KVM: x86: Mask off reserved bits in CPUID.80000008H 

stable inclusion
from stable-v5.10.154
commit 9302ebc1c21d93ef7004cd228c8b493dc64f7194
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I64YCB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9302ebc1c21d93ef7004cd228c8b493dc64f7194



--------------------------------

commit 7030d853 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: 24c82e57 ("KVM: Sanitize cpuid")
Signed-off-by: default avatarJim Mattson <jmattson@google.com>
Message-Id: <20220929225203.2234702-3-jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarLipeng Sang <sanglipeng1@jd.com>
parent f7e9643b

arch/x86/kvm/cpuid.c

+1 −0
Original line number Diff line number Diff line
@@ -966,6 +966,7 @@ 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;