[PATCH v2 1/3] KVM: arm64: Record number of signal exits as a vCPU stat

Oliver Upton
2021-07-29T22:09:33Z

Most other architectures that implement KVM record a statistic
indicating the number of times a vCPU has exited due to a pending
signal. Add support for that stat to arm64.

Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/arm.c | 1 +
arch/arm64/kvm/guest.c | 1 +
3 files changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 41911585ae0c..70e129f2b574 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -576,6 +576,7 @@ struct kvm_vcpu_stat {
u64 wfi_exit_stat;
u64 mmio_exit_user;
u64 mmio_exit_kernel;
+ u64 signal_exits;
u64 exits;
};

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e9a2b8f27792..60d0a546d7fd 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -783,6 +783,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
if (signal_pending(current)) {
ret = -EINTR;
run->exit_reason = KVM_EXIT_INTR;
+ ++vcpu->stat.signal_exits;
}

/*
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 1dfb83578277..853d1e8d2e73 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -50,6 +50,7 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
STATS_DESC_COUNTER(VCPU, mmio_exit_user),
STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
+ STATS_DESC_COUNTER(VCPU, signal_exits),
STATS_DESC_COUNTER(VCPU, exits)
};
static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
--
2.32.0.554.ge1b32706d8-goog