On Sun, Oct 18, 2015 at 01:34:42PM +0530, Amit wrote:
> From: Amit Singh Tomar <amittomer25@xxxxxxxxx>
>
> This patch adds guest exit statistics to debugfs, This can be helpful
> while measuring KVM performance.
>
> Signed-off-by: Amit Singh Tomar <amittomer25@xxxxxxxxx>
> ---
> arch/arm/include/asm/kvm_host.h | 2 ++
> arch/arm/kvm/arm.c | 1 +
> arch/arm/kvm/guest.c | 2 ++
> arch/arm/kvm/mmio.c | 1 +
> arch/arm64/include/asm/kvm_host.h | 5 +++++
> arch/arm64/kvm/guest.c | 8 ++++++++
> arch/arm64/kvm/handle_exit.c | 3 +++
> 7 files changed, 22 insertions(+)
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index c4072d9..d1f3159 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -147,6 +147,8 @@ struct kvm_vcpu_stat {
> u32 halt_successful_poll;
> u32 halt_attempted_poll;
> u32 halt_wakeup;
> + u32 mmio_exit_stat;
> + u32 exits;
> };
>
> int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 78b2869..5d0a2c5 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -569,6 +569,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
> ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);
>
> vcpu->mode = OUTSIDE_GUEST_MODE;
> + vcpu->stat.exits++;
> /*
> * Back from guest
> *************************************************************/
> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
> index 96e935b..0eea5fc 100644
> --- a/arch/arm/kvm/guest.c
> +++ b/arch/arm/kvm/guest.c
> @@ -33,6 +33,8 @@
> #define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
>
> struct kvm_stats_debugfs_item debugfs_entries[] = {
> + VCPU_STAT(mmio_exit_stat),
> + VCPU_STAT(exits),
> { NULL }
> };
>
> diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
> index 974b1c6..51d518e 100644
> --- a/arch/arm/kvm/mmio.c
> +++ b/arch/arm/kvm/mmio.c
> @@ -184,6 +184,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
> }
>
> rt = vcpu->arch.mmio_decode.rt;
> + vcpu->stat.mmio_exit_stat++;
>
> if (is_write) {
> data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), len);
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index ed03968..b32c938 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -194,6 +194,11 @@ struct kvm_vcpu_stat {
> u32 halt_successful_poll;
> u32 halt_attempted_poll;
> u32 halt_wakeup;
> + u32 hvc_exit_stat;
> + u32 wfx_exit_stat;
> + u32 wfi_exit_stat;
> + u32 mmio_exit_stat;
> + u32 exits;
> };
>
> int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index d250160..b1943cd 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -34,7 +34,15 @@
>
> #include "trace.h"
>
> +#define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
> +#define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
> +
> struct kvm_stats_debugfs_item debugfs_entries[] = {
> + VCPU_STAT(hvc_exit_stat),
> + VCPU_STAT(wfx_exit_stat),
> + VCPU_STAT(wfi_exit_stat),
> + VCPU_STAT(mmio_exit_stat),
> + VCPU_STAT(exits),
> { NULL }
> };
>
> diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
> index 68a0759..6e38c50 100644
> --- a/arch/arm64/kvm/handle_exit.c
> +++ b/arch/arm64/kvm/handle_exit.c
> @@ -39,6 +39,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
> trace_kvm_hvc_arm64(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
> kvm_vcpu_hvc_get_imm(vcpu));
> + vcpu->stat.hvc_exit_stat++;
>
> ret = kvm_psci_call(vcpu);
> if (ret < 0) {
> @@ -71,9 +72,11 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
> {
> if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
> trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
> + vcpu->stat.wfx_exit_stat++;
> kvm_vcpu_on_spin(vcpu);
> } else {
> trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
> + vcpu->stat.wfi_exit_stat++;
> kvm_vcpu_block(vcpu);
> }
>
> --
> 1.9.1
>
I thought the idea was to not use this infrastructure anymore and
instead use tracepoints to count exit reasons?
I'm cc'ing Wei here who sent some patches to QEMU for this purpose
recently.
Thanks,
-Christoffer
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