This reverts commit 8f6379e207e7d834065a080f407a60d67349d961.
The original change was not problematic but chose nonarchitected PMU
register behavior over a NULL deref as KVM failed to hide the PMU in the
ID_DFR0.
Since KVM now provides a sane value for ID_DFR0 and UNDEFs the guest for
unsupported accesses, drop the unneeded checks in PMU register handlers.
Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
---
arch/arm64/kvm/pmu-emul.c | 23 +----------------------
1 file changed, 1 insertion(+), 22 deletions(-)
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 3dc990ac4f44..78fdc443adc7 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -177,9 +177,6 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc = &pmu->pmc[select_idx];
- if (!kvm_vcpu_has_pmu(vcpu))
- return 0;
-
counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
if (kvm_pmu_pmc_is_chained(pmc) &&
@@ -201,9 +198,6 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
{
u64 reg;
- if (!kvm_vcpu_has_pmu(vcpu))
- return;
-
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);
@@ -328,9 +322,6 @@ void kvm_pmu_enable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc;
- if (!kvm_vcpu_has_pmu(vcpu))
- return;
-
if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) || !val)
return;
@@ -366,7 +357,7 @@ void kvm_pmu_disable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc;
- if (!kvm_vcpu_has_pmu(vcpu) || !val)
+ if (!val)
return;
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
@@ -536,9 +527,6 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
struct kvm_pmu *pmu = &vcpu->arch.pmu;
int i;
- if (!kvm_vcpu_has_pmu(vcpu))
- return;
-
if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E))
return;
@@ -588,9 +576,6 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
{
int i;
- if (!kvm_vcpu_has_pmu(vcpu))
- return;
-
if (val & ARMV8_PMU_PMCR_E) {
kvm_pmu_enable_counter_mask(vcpu,
__vcpu_sys_reg(vcpu, PMCNTENSET_EL0));
@@ -754,9 +739,6 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
{
u64 reg, mask;
- if (!kvm_vcpu_has_pmu(vcpu))
- return;
-
mask = ARMV8_PMU_EVTYPE_MASK;
mask &= ~ARMV8_PMU_EVTYPE_EVENT;
mask |= kvm_pmu_event_mask(vcpu->kvm);
@@ -845,9 +827,6 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
u64 val, mask = 0;
int base, i, nr_events;
- if (!kvm_vcpu_has_pmu(vcpu))
- return 0;
-
if (!pmceid1) {
val = read_sysreg(pmceid0_el0);
base = 0;
--
2.36.0.464.gb9c8b46e94-goog
