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authorAndrew Murray <andrew.murray@arm.com>2019-04-09 20:22:14 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2019-04-24 15:36:22 +0100
commit3d91befbb3a0fcec6e1eebde45c8074b88cc9441 (patch)
treedc87926a4232a95959cc882fb6c9bed5be26a9dd /arch/arm64/kvm
parentd1947bc4bc63e56014bb4d812e0db89944ed4a0f (diff)
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arm64: KVM: Enable !VHE support for :G/:H perf event modifiers
Enable/disable event counters as appropriate when entering and exiting the guest to enable support for guest or host only event counting. For both VHE and non-VHE we switch the counters between host/guest at EL2. The PMU may be on when we change which counters are enabled however we avoid adding an isb as we instead rely on existing context synchronisation events: the eret to enter the guest (__guest_enter) and eret in kvm_call_hyp for __kvm_vcpu_run_nvhe on returning. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/hyp/switch.c6
-rw-r--r--arch/arm64/kvm/pmu.c39
2 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 5444b9c6fb5c..22b4c335e0b2 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -566,6 +566,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
+ bool pmu_switch_needed;
u64 exit_code;
/*
@@ -585,6 +586,8 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
+ pmu_switch_needed = __pmu_switch_to_guest(host_ctxt);
+
__sysreg_save_state_nvhe(host_ctxt);
__activate_vm(kern_hyp_va(vcpu->kvm));
@@ -631,6 +634,9 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
*/
__debug_switch_to_host(vcpu);
+ if (pmu_switch_needed)
+ __pmu_switch_to_host(host_ctxt);
+
/* Returning to host will clear PSR.I, remask PMR if needed */
if (system_uses_irq_prio_masking())
gic_write_pmr(GIC_PRIO_IRQOFF);
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index 5414b134f99a..599e6d3f692e 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c
@@ -5,6 +5,7 @@
*/
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
+#include <asm/kvm_hyp.h>
/*
* Given the exclude_{host,guest} attributes, determine if we are going
@@ -43,3 +44,41 @@ void kvm_clr_pmu_events(u32 clr)
ctx->pmu_events.events_host &= ~clr;
ctx->pmu_events.events_guest &= ~clr;
}
+
+/**
+ * Disable host events, enable guest events
+ */
+bool __hyp_text __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenclr_el0);
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenset_el0);
+
+ return (pmu->events_host || pmu->events_guest);
+}
+
+/**
+ * Disable guest events, enable host events
+ */
+void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenclr_el0);
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenset_el0);
+}