| Message ID | 1443133885-3366-18-git-send-email-shannon.zhao@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 24/09/15 23:31, Shannon Zhao wrote: > When calling perf_event_create_kernel_counter to create perf_event, > assign a overflow handler. Then when perf event overflows, set > irq_pending and call kvm_vcpu_kick() to sync the interrupt. > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > arch/arm/kvm/arm.c | 4 ++++ > include/kvm/arm_pmu.h | 2 ++ > virt/kvm/arm/pmu.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 59 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index ce404a5..3fca263 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -28,6 +28,7 @@ > #include <linux/sched.h> > #include <linux/kvm.h> > #include <trace/events/kvm.h> > +#include <kvm/arm_pmu.h> > > #define CREATE_TRACE_POINTS > #include "trace.h" > @@ -554,6 +555,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > kvm_vgic_sync_hwstate(vcpu); > preempt_enable(); > kvm_timer_sync_hwstate(vcpu); > + kvm_pmu_sync_hwstate(vcpu); > continue; > } > > @@ -604,6 +606,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > > kvm_timer_sync_hwstate(vcpu); > > + kvm_pmu_sync_hwstate(vcpu); > + > ret = handle_exit(vcpu, run, ret); > } The code around here is about to change with Christopher's patches. Most importantly, virtual devices must signal their changes before we touch the vgic. I suspect this will have some impacts, see below. > > diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h > index 9293133..953c400 100644 > --- a/include/kvm/arm_pmu.h > +++ b/include/kvm/arm_pmu.h > @@ -38,6 +38,7 @@ struct kvm_pmu { > }; > > #ifdef CONFIG_KVM_ARM_PMU > +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu); > unsigned long kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx); > void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u32 val); > void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u32 val); > @@ -45,6 +46,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u32 val); > void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, > u32 select_idx); > #else > +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) {} > unsigned long kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx) > { > return 0; > diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c > index 18637c9..ca7e849 100644 > --- a/virt/kvm/arm/pmu.c > +++ b/virt/kvm/arm/pmu.c > @@ -21,6 +21,7 @@ > #include <linux/perf_event.h> > #include <asm/kvm_emulate.h> > #include <kvm/arm_pmu.h> > +#include <kvm/arm_vgic.h> > > static void kvm_pmu_set_evttyper(struct kvm_vcpu *vcpu, u32 idx, u32 val) > { > @@ -62,6 +63,56 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, u32 select_idx) > } > > /** > + * kvm_pmu_sync_hwstate - sync pmu state for cpu > + * @vcpu: The vcpu pointer > + * > + * Inject virtual PMU IRQ if IRQ is pending for this cpu. > + */ > +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) > +{ > + struct kvm_pmu *pmu = &vcpu->arch.pmu; > + > + if (pmu->irq_pending && (pmu->irq_num != -1)) { How likely is that pmu->irq_num could be -1? I don't think the interrupt can be made optional. > + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, pmu->irq_num, 1); > + pmu->irq_pending = false; > + } So you're signalling the interrupt as an edge, not a level. Is that an accurate modelling of the PMU interrupt? My hunch is that the interrupt should still be pending until the guest has cleared the overflow condition (by writing to PMOVSCLR_EL0). You can probably lift most of that logic from Christoffer's rework of the timer state. > +} > + > +/** > + * When perf event overflows, set irq_pending and call kvm_vcpu_kick() to inject > + * the interrupt. > + */ > +static void kvm_pmu_perf_overflow(struct perf_event *perf_event, > + struct perf_sample_data *data, > + struct pt_regs *regs) > +{ > + struct kvm_pmc *pmc = perf_event->overflow_handler_context; > + struct kvm_vcpu *vcpu = pmc->vcpu; > + struct kvm_pmu *pmu = &vcpu->arch.pmu; > + int idx = pmc->idx; > + > + if (!vcpu_mode_is_32bit(vcpu)) { > + if ((vcpu_sys_reg(vcpu, PMINTENSET_EL1) >> idx) & 0x1) { > + __set_bit(idx, > + (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSSET_EL0)); > + __set_bit(idx, > + (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSCLR_EL0)); > + pmu->irq_pending = true; > + kvm_vcpu_kick(vcpu); > + } > + } else { > + if ((vcpu_cp15(vcpu, c9_PMINTENSET) >> idx) & 0x1) { > + __set_bit(idx, > + (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSSET)); > + __set_bit(idx, > + (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSCLR)); > + pmu->irq_pending = true; > + kvm_vcpu_kick(vcpu); > + } > + } > +} > + > +/** > * kvm_pmu_get_counter_value - get PMU counter value > * @vcpu: The vcpu pointer > * @select_idx: The counter index > @@ -225,7 +276,8 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, > /* The initial sample period (overflow count) of an event. */ > attr.sample_period = (-counter) & (((u64)1 << overflow_bit) - 1); > > - event = perf_event_create_kernel_counter(&attr, -1, current, NULL, pmc); > + event = perf_event_create_kernel_counter(&attr, -1, current, > + kvm_pmu_perf_overflow, pmc); > if (IS_ERR(event)) { > printk_once("kvm: pmu event creation failed %ld\n", > PTR_ERR(event)); > Thanks, M.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index ce404a5..3fca263 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -28,6 +28,7 @@ #include <linux/sched.h> #include <linux/kvm.h> #include <trace/events/kvm.h> +#include <kvm/arm_pmu.h> #define CREATE_TRACE_POINTS #include "trace.h" @@ -554,6 +555,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_vgic_sync_hwstate(vcpu); preempt_enable(); kvm_timer_sync_hwstate(vcpu); + kvm_pmu_sync_hwstate(vcpu); continue; } @@ -604,6 +606,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_timer_sync_hwstate(vcpu); + kvm_pmu_sync_hwstate(vcpu); + ret = handle_exit(vcpu, run, ret); } diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 9293133..953c400 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -38,6 +38,7 @@ struct kvm_pmu { }; #ifdef CONFIG_KVM_ARM_PMU +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu); unsigned long kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx); void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u32 val); void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u32 val); @@ -45,6 +46,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u32 val); void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, u32 select_idx); #else +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) {} unsigned long kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx) { return 0; diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 18637c9..ca7e849 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -21,6 +21,7 @@ #include <linux/perf_event.h> #include <asm/kvm_emulate.h> #include <kvm/arm_pmu.h> +#include <kvm/arm_vgic.h> static void kvm_pmu_set_evttyper(struct kvm_vcpu *vcpu, u32 idx, u32 val) { @@ -62,6 +63,56 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, u32 select_idx) } /** + * kvm_pmu_sync_hwstate - sync pmu state for cpu + * @vcpu: The vcpu pointer + * + * Inject virtual PMU IRQ if IRQ is pending for this cpu. + */ +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + + if (pmu->irq_pending && (pmu->irq_num != -1)) { + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, pmu->irq_num, 1); + pmu->irq_pending = false; + } +} + +/** + * When perf event overflows, set irq_pending and call kvm_vcpu_kick() to inject + * the interrupt. + */ +static void kvm_pmu_perf_overflow(struct perf_event *perf_event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct kvm_pmc *pmc = perf_event->overflow_handler_context; + struct kvm_vcpu *vcpu = pmc->vcpu; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + int idx = pmc->idx; + + if (!vcpu_mode_is_32bit(vcpu)) { + if ((vcpu_sys_reg(vcpu, PMINTENSET_EL1) >> idx) & 0x1) { + __set_bit(idx, + (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSSET_EL0)); + __set_bit(idx, + (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSCLR_EL0)); + pmu->irq_pending = true; + kvm_vcpu_kick(vcpu); + } + } else { + if ((vcpu_cp15(vcpu, c9_PMINTENSET) >> idx) & 0x1) { + __set_bit(idx, + (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSSET)); + __set_bit(idx, + (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSCLR)); + pmu->irq_pending = true; + kvm_vcpu_kick(vcpu); + } + } +} + +/** * kvm_pmu_get_counter_value - get PMU counter value * @vcpu: The vcpu pointer * @select_idx: The counter index @@ -225,7 +276,8 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, /* The initial sample period (overflow count) of an event. */ attr.sample_period = (-counter) & (((u64)1 << overflow_bit) - 1); - event = perf_event_create_kernel_counter(&attr, -1, current, NULL, pmc); + event = perf_event_create_kernel_counter(&attr, -1, current, + kvm_pmu_perf_overflow, pmc); if (IS_ERR(event)) { printk_once("kvm: pmu event creation failed %ld\n", PTR_ERR(event));
When calling perf_event_create_kernel_counter to create perf_event, assign a overflow handler. Then when perf event overflows, set irq_pending and call kvm_vcpu_kick() to sync the interrupt. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> --- arch/arm/kvm/arm.c | 4 ++++ include/kvm/arm_pmu.h | 2 ++ virt/kvm/arm/pmu.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 59 insertions(+), 1 deletion(-)