This is a note to let you know that I've just added the patch titled
kvm: x86/pmu: Fix the compare function used by the pmu event filter
to the 5.10-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-pmu-fix-the-compare-function-used-by-the-pmu-event-filter.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4ac19ead0dfbabd8e0bfc731f507cfb0b95d6c99 Mon Sep 17 00:00:00 2001
From: Aaron Lewis <aaronlewis@xxxxxxxxxx>
Date: Tue, 17 May 2022 05:12:36 +0000
Subject: kvm: x86/pmu: Fix the compare function used by the pmu event filter
From: Aaron Lewis <aaronlewis@xxxxxxxxxx>
commit 4ac19ead0dfbabd8e0bfc731f507cfb0b95d6c99 upstream.
When returning from the compare function the u64 is truncated to an
int. This results in a loss of the high nybble[1] in the event select
and its sign if that nybble is in use. Switch from using a result that
can end up being truncated to a result that can only be: 1, 0, -1.
[1] bits 35:32 in the event select register and bits 11:8 in the event
select.
Fixes: 7ff775aca48ad ("KVM: x86/pmu: Use binary search to check filtered events")
Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20220517051238.2566934-1-aaronlewis@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/pmu.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -170,9 +170,12 @@ static bool pmc_resume_counter(struct kv
return true;
}
-static int cmp_u64(const void *a, const void *b)
+static int cmp_u64(const void *pa, const void *pb)
{
- return *(__u64 *)a - *(__u64 *)b;
+ u64 a = *(u64 *)pa;
+ u64 b = *(u64 *)pb;
+
+ return (a > b) - (a < b);
}
void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
Patches currently in stable-queue which might be from aaronlewis@xxxxxxxxxx are
queue-5.10/kvm-x86-pmu-fix-the-compare-function-used-by-the-pmu-event-filter.patch
