KVM: arm64: Record number of signal exits as a vCPU stat

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>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210802192809.1851010-2-oupton@google.com

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 41911585ae0cfa3db73e6c67b78e88e0e781a118..70e129f2b574a74986c2d5fe8a1d93284c321537 100644 (file)
--- 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 e9a2b8f277922f85ed33ac4c09eefb75f7c5613c..60d0a546d7fd88e0cb75cacd4a2860af83b3428c 100644 (file)
--- 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 1dfb83578277091f539cc986852405a1178983b7..853d1e8d2e738f2b8be7dbf59bda560f5d8d277b 100644 (file)
--- 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) ==