| Message ID | 20240403080452.1007601-9-atishp@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | RISC-V SBI v2.0 PMU improvements and Perf sampling in KVM guest | expand |
On Wed, Apr 03, 2024 at 01:04:37AM -0700, Atish Patra wrote: > 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. > > Signed-off-by: Atish Patra <atishp@rivosinc.com> > --- > 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 > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
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;
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. Signed-off-by: Atish Patra <atishp@rivosinc.com> --- arch/riscv/kvm/vcpu_pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)