From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
Noting pause loop exited vcpu helps in filtering right candidate to yield.
Yielding to same vcpu may result in more wastage of cpu.
Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 11 +++++++++++
arch/x86/kvm/svm.c | 1 +
arch/x86/kvm/vmx.c | 1 +
arch/x86/kvm/x86.c | 4 +++-
4 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index db7c1f2..386f3e6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -484,6 +484,17 @@ struct kvm_vcpu_arch {
u64 length;
u64 status;
} osvw;
+
+ /*
+ * Pause loop exit optimization
+ * pause_loop_exited: set when a vcpu does a pause loop exit.
+ * dy_eligible: indicates whether vcpu is eligible for directed yield.
+ */
+ struct {
+ bool pause_loop_exited;
+ bool dy_eligible;
+ } ple;
+
};
struct kvm_lpage_info {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f75af40..2b4b4ee 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3264,6 +3264,7 @@ static int interrupt_window_interception(struct vcpu_svm *svm)
static int pause_interception(struct vcpu_svm *svm)
{
+ svm->vcpu.arch.ple.pause_loop_exited = true;
kvm_vcpu_on_spin(&(svm->vcpu));
return 1;
}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 32eb588..14aa67a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4945,6 +4945,7 @@ out:
static int handle_pause(struct kvm_vcpu *vcpu)
{
skip_emulated_instruction(vcpu);
+ vcpu->arch.ple.pause_loop_exited = true;
kvm_vcpu_on_spin(vcpu);
return 1;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index be6d549..b30c310 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5331,7 +5331,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (req_immediate_exit)
smp_send_reschedule(vcpu->cpu);
-
+ vcpu->arch.ple.pause_loop_exited = false;
kvm_guest_enter();
if (unlikely(vcpu->arch.switch_db_regs)) {
@@ -6168,6 +6168,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
BUG_ON(vcpu->kvm == NULL);
kvm = vcpu->kvm;
+ vcpu->arch.ple.pause_loop_exited = false;
+ vcpu->arch.ple.dy_eligible = false;
vcpu->arch.emulate_ctxt.ops = &emulate_ops;
if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_bsp(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
