From 68ca7663c75b099539fe675fc5387dee44d3a6cc Mon Sep 17 00:00:00 2001
From: Wanpeng Li <wanpengli@tencent.com>
Date: Thu, 10 Sep 2020 17:50:40 +0800
Subject: [PATCH] KVM: LAPIC: Narrow down the kick target vCPU
The kick after setting KVM_REQ_PENDING_TIMER is used to handle the timer
fires on a different pCPU which vCPU is running on. This kick costs about
1000 clock cycles and we don't need this when injecting already-expired
timer or when using the VMX preemption timer because
kvm_lapic_expired_hv_timer() is called from the target vCPU.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1599731444-3525-6-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 4 +++-
arch/x86/kvm/x86.c | 6 ------
arch/x86/kvm/x86.h | 1 -
3 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index e446bdff70ec49..3b32d3b094b5b2 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1642,7 +1642,9 @@ static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn)
}
atomic_inc(&apic->lapic_timer.pending);
- kvm_set_pending_timer(vcpu);
+ kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
+ if (from_timer_fn)
+ kvm_vcpu_kick(vcpu);
}
static void start_sw_tscdeadline(struct kvm_lapic *apic)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1994602a0851f2..836baad47fe979 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1774,12 +1774,6 @@ static s64 get_kvmclock_base_ns(void)
}
#endif
-void kvm_set_pending_timer(struct kvm_vcpu *vcpu)
-{
- kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
- kvm_vcpu_kick(vcpu);
-}
-
static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
{
int version;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 995ab696dcf069..ea20b8bfd5dc6e 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -246,7 +246,6 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu)
return is_smm(vcpu) || kvm_x86_ops.apic_init_signal_blocked(vcpu);
}
-void kvm_set_pending_timer(struct kvm_vcpu *vcpu);
void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr);
--
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