This is a note to let you know that I've just added the patch titled
KVM: x86: Mask off reserved bits in CPUID.80000006H
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.80000006h.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 eeb69eab57c6604ac90b3fd8e5ac43f24a5535b1 Mon Sep 17 00:00:00 2001
From: Jim Mattson <jmattson@xxxxxxxxxx>
Date: Thu, 29 Sep 2022 15:51:59 -0700
Subject: KVM: x86: Mask off reserved bits in CPUID.80000006H
From: Jim Mattson <jmattson@xxxxxxxxxx>
commit eeb69eab57c6604ac90b3fd8e5ac43f24a5535b1 upstream.
KVM_GET_SUPPORTED_CPUID should only enumerate features that KVM
actually supports. CPUID.80000006H:EDX[17:16] are reserved bits and
should be masked off.
Fixes: 43d05de2bee7 ("KVM: pass through CPUID(0x80000006)")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Message-Id: <20220929225203.2234702-2-jmattson@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
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
@@ -906,7 +906,8 @@ static inline int __do_cpuid_func(struct
cpuid_entry_override(entry, CPUID_8000_0001_ECX);
break;
case 0x80000006:
- /* L2 cache and TLB: pass through host info. */
+ /* Drop reserved bits, pass host L2 cache and TLB info. */
+ entry->edx &= ~GENMASK(17, 16);
break;
case 0x80000007: /* Advanced power management */
/* invariant TSC is CPUID.80000007H:EDX[8] */
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
