This is a note to let you know that I've just added the patch titled
RISC-V: KVM: Fix the initial sample period value
to the 6.6-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:
risc-v-kvm-fix-the-initial-sample-period-value.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 28e6d912a51d2c24234461dc4cd12093a0a2f9f3
Author: Atish Patra <atishp@xxxxxxxxxxxx>
Date: Sat Apr 20 08:17:26 2024 -0700
RISC-V: KVM: Fix the initial sample period value
[ Upstream commit 57990ab90ce31aadac0d5a6293f5582e24ff7521 ]
The initial sample period value when counter value is not assigned
should be set to maximum value supported by the counter width.
Otherwise, it may result in spurious interrupts.
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240420151741.962500-11-atishp@xxxxxxxxxxxx
Signed-off-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index 86391a5061dda..cee1b9ca4ec48 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -39,7 +39,7 @@ static u64 kvm_pmu_get_sample_period(struct kvm_pmc *pmc)
u64 sample_period;
if (!pmc->counter_val)
- sample_period = counter_val_mask + 1;
+ sample_period = counter_val_mask;
else
sample_period = (-pmc->counter_val) & counter_val_mask;
