[PATCH v6 10/24] RISC-V: KVM: Fix the initial sample period value

From: Atish Patra
Date: Wed Apr 10 2024 - 20:11:45 EST


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>
---
arch/riscv/kvm/vcpu_pmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index 86391a5061dd..cee1b9ca4ec4 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;

--
2.34.1