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 <coltonle...@google.com>
---
 arch/arm64/include/asm/kvm_pmu.h |  2 ++
 arch/arm64/kvm/pmu-emul.c        |  4 ++--
 arch/arm64/kvm/pmu-part.c        | 22 +++++++++++++++++++++-
 arch/arm64/kvm/pmu.c             |  6 +++++-
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pmu.h b/arch/arm64/include/asm/kvm_pmu.h
index 03e3bd318e4b..d047def897bc 100644
--- a/arch/arm64/include/asm/kvm_pmu.h
+++ b/arch/arm64/include/asm/kvm_pmu.h
@@ -86,6 +86,8 @@ bool pmu_access_el0_disabled(struct kvm_vcpu *vcpu);
 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-emul.c b/arch/arm64/kvm/pmu-emul.c
index bcaa9f7a8ca2..6f41fc3e3f74 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-part.c b/arch/arm64/kvm/pmu-part.c
index bd04c37b19b9..165d1eae2634 100644
--- a/arch/arm64/kvm/pmu-part.c
+++ b/arch/arm64/kvm/pmu-part.c
@@ -279,7 +279,7 @@ void kvm_pmu_load(struct kvm_vcpu *vcpu)
        write_pmcr(val);
 
        /*
-        * Loading these registers is tricky because of
+        * Loading these registers is more intricate because of
         * 1. Applying only the bits for guest counters (indicated by mask)
         * 2. Setting and clearing are different registers
         */
@@ -355,3 +355,23 @@ 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.c b/arch/arm64/kvm/pmu.c
index 9469f1e0a0b6..6ab0d23f9251 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;
 
-- 
2.50.0.727.gbf7dc18ff4-goog


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