KVM: x86: Mask off reserved bits in CPUID.80000001H

stable inclusion
from stable-v5.10.154
commit e0c7410378cd1adbfd35a65faca5df8936631b1a
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=e0c7410378cd1adbfd35a65faca5df8936631b1a

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

commit 0469e56a upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. CPUID.80000001:EBX[27:16] are reserved bits and
should be masked off.

Fixes: 07716717 ("KVM: Enhance guest cpuid management")
Signed-off-by: NJim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLipeng Sang <sanglipeng1@jd.com>
(cherry picked from commit d6c7c247)

arch/x86/kvm/cpuid.c

@@ -939,6 +939,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		entry->eax = min(entry->eax, 0x8000001f);
 		break;
 	case 0x80000001:
+		entry->ebx &= ~GENMASK(27, 16);
 		cpuid_entry_override(entry, CPUID_8000_0001_EDX);
 		cpuid_entry_override(entry, CPUID_8000_0001_ECX);
 		break;