From 0f1e261ead16ce09169bf2d223d4c8803576f85e Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Sat, 17 Dec 2016 16:05:19 +0100
Subject: [PATCH] KVM: x86: add VCPU stat for KVM_REQ_EVENT processing
This statistic can be useful to estimate the cost of an IRQ injection
scenario, by comparing it with irq_injections. For example the stat
shows that sti;hlt triggers more KVM_REQ_EVENT than sti;nop.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 2 ++
2 files changed, 3 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0419e114f27b..417502cf42b6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -861,6 +861,7 @@ struct kvm_vcpu_stat {
u64 hypercalls;
u64 irq_injections;
u64 nmi_injections;
+ u64 req_event;
};
struct x86_instruction_info;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index edff19d1df97..b02af6285887 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -180,6 +180,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "insn_emulation_fail", VCPU_STAT(insn_emulation_fail) },
{ "irq_injections", VCPU_STAT(irq_injections) },
{ "nmi_injections", VCPU_STAT(nmi_injections) },
+ { "req_event", VCPU_STAT(req_event) },
{ "mmu_shadow_zapped", VM_STAT(mmu_shadow_zapped) },
{ "mmu_pte_write", VM_STAT(mmu_pte_write) },
{ "mmu_pte_updated", VM_STAT(mmu_pte_updated) },
@@ -6756,6 +6757,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
}
if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
+ ++vcpu->stat.req_event;
kvm_apic_accept_events(vcpu);
if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
r = 1;