[PATCH v5 21/24] KVM: arm64: Inject recorded guest interrupts
From: Colton Lewis <hidden>
Date: 2025-12-09 20:52:55
Also in:
kvm, kvmarm, linux-doc, linux-kselftest, linux-perf-users, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
When we re-enter the VM after handling a PMU interrupt, calculate whether it was any of the guest counters that overflowed and inject an interrupt into the guest if so. Signed-off-by: Colton Lewis <redacted> --- arch/arm64/include/asm/kvm_pmu.h | 2 ++ arch/arm64/kvm/pmu-direct.c | 20 ++++++++++++++++++++ arch/arm64/kvm/pmu-emul.c | 4 ++-- arch/arm64/kvm/pmu.c | 6 +++++- 4 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_pmu.h b/arch/arm64/include/asm/kvm_pmu.h
index e4cbab0fd09cf..47e6f2a14e381 100644
--- a/arch/arm64/include/asm/kvm_pmu.h
+++ b/arch/arm64/include/asm/kvm_pmu.h@@ -92,6 +92,8 @@ bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx); void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu); void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu); void kvm_vcpu_pmu_resync_el0(void); +bool kvm_pmu_emul_overflow_status(struct kvm_vcpu *vcpu); +bool kvm_pmu_part_overflow_status(struct kvm_vcpu *vcpu); #define kvm_vcpu_has_pmu(vcpu) \ (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PMU_V3))
diff --git a/arch/arm64/kvm/pmu-direct.c b/arch/arm64/kvm/pmu-direct.c
index 76d8ed24c8646..2ee99d6d2b6c1 100644
--- a/arch/arm64/kvm/pmu-direct.c
+++ b/arch/arm64/kvm/pmu-direct.c@@ -413,3 +413,23 @@ void kvm_pmu_handle_guest_irq(u64 govf) __vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, |=, govf); } + +/** + * kvm_pmu_part_overflow_status() - Determine if any guest counters have overflowed + * @vcpu: Ponter to struct kvm_vcpu + * + * Determine if any guest counters have overflowed and therefore an + * IRQ needs to be injected into the guest. + * + * Return: True if there was an overflow, false otherwise + */ +bool kvm_pmu_part_overflow_status(struct kvm_vcpu *vcpu) +{ + struct arm_pmu *pmu = vcpu->kvm->arch.arm_pmu; + u64 mask = kvm_pmu_guest_counter_mask(pmu); + u64 pmovs = __vcpu_sys_reg(vcpu, PMOVSSET_EL0); + u64 pmint = read_pmintenset(); + u64 pmcr = read_pmcr(); + + return (pmcr & ARMV8_PMU_PMCR_E) && (mask & pmovs & pmint); +}
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index bcaa9f7a8ca28..6f41fc3e3f74b 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c@@ -268,7 +268,7 @@ void kvm_pmu_reprogram_counter_mask(struct kvm_vcpu *vcpu, u64 val) * counter where the values of the global enable control, PMOVSSET_EL0[n], and * PMINTENSET_EL1[n] are all 1. */ -bool kvm_pmu_overflow_status(struct kvm_vcpu *vcpu) +bool kvm_pmu_emul_overflow_status(struct kvm_vcpu *vcpu) { u64 reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0);
@@ -405,7 +405,7 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event, kvm_pmu_counter_increment(vcpu, BIT(idx + 1), ARMV8_PMUV3_PERFCTR_CHAIN); - if (kvm_pmu_overflow_status(vcpu)) { + if (kvm_pmu_emul_overflow_status(vcpu)) { kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); if (!in_nmi())
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index c9862e55a4049..e1332a158dfc8 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c@@ -407,7 +407,11 @@ static void kvm_pmu_update_state(struct kvm_vcpu *vcpu) struct kvm_pmu *pmu = &vcpu->arch.pmu; bool overflow; - overflow = kvm_pmu_overflow_status(vcpu); + if (kvm_vcpu_pmu_is_partitioned(vcpu)) + overflow = kvm_pmu_part_overflow_status(vcpu); + else + overflow = kvm_pmu_emul_overflow_status(vcpu); + if (pmu->irq_level == overflow) return;
--
2.52.0.239.gd5f0c6e74e-goog