Commit 3d91befb authored by Andrew Murray's avatar Andrew Murray Committed by Marc Zyngier

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: default avatarAndrew Murray <andrew.murray@arm.com>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent d1947bc4
...@@ -591,6 +591,9 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) ...@@ -591,6 +591,9 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr); void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr);
void kvm_clr_pmu_events(u32 clr); void kvm_clr_pmu_events(u32 clr);
void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt);
bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt);
#else #else
static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {} static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {}
static inline void kvm_clr_pmu_events(u32 clr) {} static inline void kvm_clr_pmu_events(u32 clr) {}
......
...@@ -566,6 +566,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) ...@@ -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 *host_ctxt;
struct kvm_cpu_context *guest_ctxt; struct kvm_cpu_context *guest_ctxt;
bool pmu_switch_needed;
u64 exit_code; u64 exit_code;
/* /*
...@@ -585,6 +586,8 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) ...@@ -585,6 +586,8 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
host_ctxt->__hyp_running_vcpu = vcpu; host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt; guest_ctxt = &vcpu->arch.ctxt;
pmu_switch_needed = __pmu_switch_to_guest(host_ctxt);
__sysreg_save_state_nvhe(host_ctxt); __sysreg_save_state_nvhe(host_ctxt);
__activate_vm(kern_hyp_va(vcpu->kvm)); __activate_vm(kern_hyp_va(vcpu->kvm));
...@@ -631,6 +634,9 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) ...@@ -631,6 +634,9 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
*/ */
__debug_switch_to_host(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 */ /* Returning to host will clear PSR.I, remask PMR if needed */
if (system_uses_irq_prio_masking()) if (system_uses_irq_prio_masking())
gic_write_pmr(GIC_PRIO_IRQOFF); gic_write_pmr(GIC_PRIO_IRQOFF);
......
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
*/ */
#include <linux/kvm_host.h> #include <linux/kvm_host.h>
#include <linux/perf_event.h> #include <linux/perf_event.h>
#include <asm/kvm_hyp.h>
/* /*
* Given the exclude_{host,guest} attributes, determine if we are going * Given the exclude_{host,guest} attributes, determine if we are going
...@@ -43,3 +44,41 @@ void kvm_clr_pmu_events(u32 clr) ...@@ -43,3 +44,41 @@ void kvm_clr_pmu_events(u32 clr)
ctx->pmu_events.events_host &= ~clr; ctx->pmu_events.events_host &= ~clr;
ctx->pmu_events.events_guest &= ~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);
}
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment