[PATCH 22/23] KVM: arm64: pmu: Only handle supported event counters

Marc Zyngier
2020-01-30T13:29:25Z

From: Eric Auger <eric.auger@redhat.com>

Let the code never use unsupported event counters. Change
kvm_pmu_handle_pmcr() to only reset supported counters and
kvm_pmu_vcpu_reset() to only stop supported counters.

Other actions are filtered on the supported counters in
kvm/sysregs.c

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-5-eric.auger@redhat.com
---
virt/kvm/arm/pmu.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 560db6282137..f0d0312c0a55 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -247,10 +247,11 @@ void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu)
*/
void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu)
{
- int i;
+ unsigned long mask = kvm_pmu_valid_counter_mask(vcpu);
struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ int i;

- for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++)
+ for_each_set_bit(i, &mask, 32)
kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]);

bitmap_zero(vcpu->arch.pmu.chained, ARMV8_PMU_MAX_COUNTER_PAIRS);
@@ -527,10 +528,9 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
*/
void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
{
- u64 mask;
+ unsigned long mask = kvm_pmu_valid_counter_mask(vcpu);
int i;

- mask = kvm_pmu_valid_counter_mask(vcpu);
if (val & ARMV8_PMU_PMCR_E) {
kvm_pmu_enable_counter_mask(vcpu,
__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask);
@@ -542,7 +542,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0);

if (val & ARMV8_PMU_PMCR_P) {
- for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++)
+ for_each_set_bit(i, &mask, 32)
kvm_pmu_set_counter_value(vcpu, i, 0);
}
}
--
2.20.1