This is a note to let you know that I've just added the patch titled
KVM: x86: Mask off reserved bits in CPUID.8000001FH
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-mask-off-reserved-bits-in-cpuid.8000001fh.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 86c4f0d547f6460d0426ebb3ba0614f1134b8cda Mon Sep 17 00:00:00 2001
From: Jim Mattson <jmattson@xxxxxxxxxx>
Date: Thu, 29 Sep 2022 15:52:03 -0700
Subject: KVM: x86: Mask off reserved bits in CPUID.8000001FH
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).
Patches currently in stable-queue which might be from jmattson@xxxxxxxxxx are
queue-5.15/kvm-x86-mask-off-reserved-bits-in-cpuid.80000008h.patch
queue-5.15/kvm-x86-mask-off-reserved-bits-in-cpuid.80000006h.patch
queue-5.15/kvm-x86-mask-off-reserved-bits-in-cpuid.80000001h.patch
queue-5.15/kvm-x86-mask-off-reserved-bits-in-cpuid.8000001ah.patch
queue-5.15/kvm-x86-mask-off-reserved-bits-in-cpuid.8000001fh.patch
