Hi Andrew,
On 22/01/2019 10:49, Andrew Murray wrote:
> The perf event sample_period is currently set based upon the current
> counter value, when PMXEVTYPER is written to and the perf event is created.
> However the user may choose to write the type before the counter value in
> which case sample_period will be set incorrectly. Let's instead decouple
> event creation from PMXEVTYPER and (re)create the event in either
> suitation.
>
> Signed-off-by: Andrew Murray <andrew.murray@xxxxxxx>
> ---
> virt/kvm/arm/pmu.c | 39 ++++++++++++++++++++++++++++++---------
> 1 file changed, 30 insertions(+), 9 deletions(-)
>
> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
> index 531d27f..4464899 100644
> --- a/virt/kvm/arm/pmu.c
> +++ b/virt/kvm/arm/pmu.c
> @@ -24,6 +24,8 @@
> #include <kvm/arm_pmu.h>
> #include <kvm/arm_vgic.h>
>
> +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 data,
> + u64 select_idx);
> /**
> * kvm_pmu_get_counter_value - get PMU counter value
> * @vcpu: The vcpu pointer
> @@ -57,11 +59,18 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
> */
> void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
> {
> - u64 reg;
> + u64 reg, data;
>
> reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
> ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
> __vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
> +
> + reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
> + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx;
> + data = __vcpu_sys_reg(vcpu, reg + select_idx);
I think this should be just "reg" instead of "reg + select_idx".
Cheers,
--
Julien Thierry
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