diff options
author | Andrew Murray <andrew.murray@arm.com> | 2019-04-09 21:22:12 +0200 |
---|---|---|
committer | Marc Zyngier <marc.zyngier@arm.com> | 2019-04-24 16:35:30 +0200 |
commit | eb41238cf19fda694e3a99c1f4f58bd88479a5ee (patch) | |
tree | c96096fc7b28a5d0d5969e882a9cd39d946544b1 /arch/arm64/kvm | |
parent | arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_data (diff) | |
download | linux-eb41238cf19fda694e3a99c1f4f58bd88479a5ee.tar.xz linux-eb41238cf19fda694e3a99c1f4f58bd88479a5ee.zip |
arm64: KVM: Add accessors to track guest/host only counters
In order to effeciently switch events_{guest,host} perf counters at
guest entry/exit we add bitfields to kvm_cpu_context for guest and host
events as well as accessors for updating them.
A function is also provided which allows the PMU driver to determine
if a counter should start counting when it is enabled. With exclude_host,
we may only start counting when entering the guest.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r-- | arch/arm64/kvm/Makefile | 2 | ||||
-rw-r--r-- | arch/arm64/kvm/pmu.c | 45 |
2 files changed, 46 insertions, 1 deletions
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 690e033a91c0..3ac1a64d2fb9 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -17,7 +17,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/psci.o $(KVM)/arm/perf.o kvm-$(CONFIG_KVM_ARM_HOST) += inject_fault.o regmap.o va_layout.o kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o kvm-$(CONFIG_KVM_ARM_HOST) += guest.o debug.o reset.o sys_regs.o sys_regs_generic_v8.o -kvm-$(CONFIG_KVM_ARM_HOST) += vgic-sys-reg-v3.o fpsimd.o +kvm-$(CONFIG_KVM_ARM_HOST) += vgic-sys-reg-v3.o fpsimd.o pmu.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/aarch32.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic.o diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c new file mode 100644 index 000000000000..5414b134f99a --- /dev/null +++ b/arch/arm64/kvm/pmu.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 Arm Limited + * Author: Andrew Murray <Andrew.Murray@arm.com> + */ +#include <linux/kvm_host.h> +#include <linux/perf_event.h> + +/* + * Given the exclude_{host,guest} attributes, determine if we are going + * to need to switch counters at guest entry/exit. + */ +static bool kvm_pmu_switch_needed(struct perf_event_attr *attr) +{ + /* Only switch if attributes are different */ + return (attr->exclude_host != attr->exclude_guest); +} + +/* + * Add events to track that we may want to switch at guest entry/exit + * time. + */ +void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) +{ + struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data); + + if (!kvm_pmu_switch_needed(attr)) + return; + + if (!attr->exclude_host) + ctx->pmu_events.events_host |= set; + if (!attr->exclude_guest) + ctx->pmu_events.events_guest |= set; +} + +/* + * Stop tracking events + */ +void kvm_clr_pmu_events(u32 clr) +{ + struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data); + + ctx->pmu_events.events_host &= ~clr; + ctx->pmu_events.events_guest &= ~clr; +} |