[Android-virt] [PATCH 15/15] ARM: KVM: Add exit statistics to debugfs

[c.dall at virtualopensystems.com (Christoffer Dall)]

On Mon, May 14, 2012 at 9:06 AM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> Exit statistics can be a very valuable information when looking
> at KVM performance.
>
> Expose them through debugfs.
>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
> ?arch/arm/include/asm/kvm_host.h | ? ?5 +++++
> ?arch/arm/kvm/arm.c ? ? ? ? ? ? ?| ? ?5 ++++-
> ?arch/arm/kvm/emulate.c ? ? ? ? ?| ? ?1 +
> ?arch/arm/kvm/guest.c ? ? ? ? ? ?| ? 13 +++++++++++++
> ?arch/arm/kvm/mmu.c ? ? ? ? ? ? ?| ? ?8 ++++++++
> ?5 files changed, 31 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index e6fd8ff..ffef12b 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -118,6 +118,11 @@ struct kvm_vm_stat {
> ?};
>
> ?struct kvm_vcpu_stat {
> + ? ? ? u32 exits;
> + ? ? ? u32 mmio_exits;
> + ? ? ? u32 kmmio_exits;
> + ? ? ? u32 wfi_exits;
> + ? ? ? u32 irq_exits;
> ? ? ? ?u32 halt_wakeup;
> ?};
>
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 7cd8190..86eca66 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -435,8 +435,10 @@ static inline int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
> ?{
> ? ? ? ?unsigned long hsr_ec;
>
> - ? ? ? if (exception_index == ARM_EXCEPTION_IRQ)
> + ? ? ? if (exception_index == ARM_EXCEPTION_IRQ) {
> + ? ? ? ? ? ? ? vcpu->stat.irq_exits++;
> ? ? ? ? ? ? ? ?return 0;
> + ? ? ? }
>
> ? ? ? ?if (exception_index != ARM_EXCEPTION_HVC) {
> ? ? ? ? ? ? ? ?kvm_pr_unimpl("Unsupported exception type: %d",
> @@ -514,6 +516,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
> ? ? ? ? ? ? ? ?kvm_vgic_sync_from_cpu(vcpu);
> ? ? ? ? ? ? ? ?vcpu->mode = OUTSIDE_GUEST_MODE;
> + ? ? ? ? ? ? ? vcpu->stat.exits++;
> ? ? ? ? ? ? ? ?kvm_guest_exit();
> ? ? ? ? ? ? ? ?local_irq_enable();
>
> diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
> index d810c30..3ceab47 100644
> --- a/arch/arm/kvm/emulate.c
> +++ b/arch/arm/kvm/emulate.c
> @@ -443,6 +443,7 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> ?int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
> ?{
> ? ? ? ?trace_kvm_wfi(vcpu->arch.regs.pc);
> + ? ? ? vcpu->stat.wfi_exits++;
> ? ? ? ?if (!vcpu->arch.irq_lines && !kvm_vgic_vcpu_pending_irq(vcpu))
> ? ? ? ? ? ? ? ?vcpu->arch.wait_for_interrupts = 1;
> ? ? ? ?return 0;
> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
> index c0adab0..d2ad91a 100644
> --- a/arch/arm/kvm/guest.c
> +++ b/arch/arm/kvm/guest.c
> @@ -24,7 +24,20 @@
> ?#include <asm/kvm_asm.h>
> ?#include <asm/kvm_emulate.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 stats */
> + ? ? ? VCPU_STAT(exits),
> + ? ? ? VCPU_STAT(mmio_exits),
> + ? ? ? VCPU_STAT(kmmio_exits),
> + ? ? ? VCPU_STAT(wfi_exits),
> + ? ? ? VCPU_STAT(irq_exits),
> + ? ? ? VCPU_STAT(halt_wakeup),
> +
> + ? ? ? /* vm stats */
> + ? ? ? VM_STAT(remote_tlb_flush),
> ? ? ? ?{ NULL }
> ?};
>
> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
> index 2d4fc68..04898d8 100644
> --- a/arch/arm/kvm/mmu.c
> +++ b/arch/arm/kvm/mmu.c
> @@ -604,6 +604,14 @@ static int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
> ? ? ? ? ? ? ? ?memcpy(run->mmio.data, vcpu_reg(vcpu, rd), len);
>
> ? ? ? ?run->exit_reason = vgic_handle_mmio(vcpu, run);
> + ? ? ? switch (run->exit_reason) {
> + ? ? ? case KVM_EXIT_MMIO:
> + ? ? ? ? ? ? ? vcpu->stat.mmio_exits++;
> + ? ? ? ? ? ? ? break;
> + ? ? ? case KVM_EXIT_UNKNOWN:
> + ? ? ? ? ? ? ? vcpu->stat.kmmio_exits++;
> + ? ? ? ? ? ? ? break;
> + ? ? ? }
>
> ? ? ? ?/*
> ? ? ? ? * The MMIO instruction is emulated and should not be re-executed
> --
> 1.7.7.1
>
nice.

Thanks,
-Christoffer