[PATCH 5.15 130/144] KVM: x86: Mask off reserved bits in CPUID.8000001FH

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From: Jim Mattson <jmattson@xxxxxxxxxx>

commit 86c4f0d547f6460d0426ebb3ba0614f1134b8cda upstream.

KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. CPUID.8000001FH:EBX[31:16] are reserved bits and
should be masked off.

Fixes: 8765d75329a3 ("KVM: X86: Extend CPUID range to include new leaf")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Message-Id: <20220929225203.2234702-6-jmattson@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
[Clear NumVMPL too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/kvm/cpuid.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -968,7 +968,8 @@ static inline int __do_cpuid_func(struct
 			entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
 		} else {
 			cpuid_entry_override(entry, CPUID_8000_001F_EAX);
-
+			/* Clear NumVMPL since KVM does not support VMPL.  */
+			entry->ebx &= ~GENMASK(31, 12);
 			/*
 			 * Enumerate '0' for "PA bits reduction", the adjusted
 			 * MAXPHYADDR is enumerated directly (see 0x80000008).





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