KVM: x86: Mask off reserved bits in CPUID.8000001FH

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@google.com>
Message-Id: <20220929225203.2234702-6-jmattson@google.com>
Cc: stable@vger.kernel.org
[Clear NumVMPL too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8f2a803ad0360c35870d0932240fb069dcb34a80..05b27b4a54c9dde9a2c22d3631fb4734cb4f6d19 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -968,7 +968,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
                        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).