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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org, Liran Alon <liran.alon@oracle.com>,
	Wanpeng Li <wanpengli@tencent.com>
Subject: [PATCH v3 7/9] KVM: lapic: Refactor ->set_hv_timer to use an explicit expired param
Date: Tue, 16 Apr 2019 13:32:46 -0700	[thread overview]
Message-ID: <20190416203248.29429-8-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20190416203248.29429-1-sean.j.christopherson@intel.com>

Refactor kvm_x86_ops->set_hv_timer to use an explicit parameter for
stating that the timer has expired.  Overloading the return value is
unnecessarily clever, e.g. can lead to confusion over the proper return
value from start_hv_timer() when r==1.

Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/include/asm/kvm_host.h |  3 ++-
 arch/x86/kvm/lapic.c            | 10 +++++-----
 arch/x86/kvm/vmx/vmx.c          |  6 ++++--
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a9d03af34030..501a8209285b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1167,7 +1167,8 @@ struct kvm_x86_ops {
 			      uint32_t guest_irq, bool set);
 	void (*apicv_post_state_restore)(struct kvm_vcpu *vcpu);
 
-	int (*set_hv_timer)(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc);
+	int (*set_hv_timer)(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
+			    bool *expired);
 	void (*cancel_hv_timer)(struct kvm_vcpu *vcpu);
 
 	void (*setup_mce)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index bdcf04689a80..9a09a41000c3 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1681,7 +1681,8 @@ static void cancel_hv_timer(struct kvm_lapic *apic)
 static bool start_hv_timer(struct kvm_lapic *apic)
 {
 	struct kvm_timer *ktimer = &apic->lapic_timer;
-	int r;
+	struct kvm_vcpu *vcpu = apic->vcpu;
+	bool expired;
 
 	WARN_ON(preemptible());
 	if (!kvm_x86_ops->set_hv_timer)
@@ -1693,8 +1694,7 @@ static bool start_hv_timer(struct kvm_lapic *apic)
 	if (!ktimer->tscdeadline)
 		return false;
 
-	r = kvm_x86_ops->set_hv_timer(apic->vcpu, ktimer->tscdeadline);
-	if (r < 0)
+	if (kvm_x86_ops->set_hv_timer(vcpu, ktimer->tscdeadline, &expired))
 		return false;
 
 	ktimer->hv_timer_in_use = true;
@@ -1712,13 +1712,13 @@ static bool start_hv_timer(struct kvm_lapic *apic)
 		 */
 		if (atomic_read(&ktimer->pending)) {
 			cancel_hv_timer(apic);
-		} else if (r) {
+		} else if (expired) {
 			apic_timer_expired(apic);
 			cancel_hv_timer(apic);
 		}
 	}
 
-	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, ktimer->hv_timer_in_use);
+	trace_kvm_hv_timer_state(vcpu->vcpu_id, ktimer->hv_timer_in_use);
 
 	return true;
 }
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a3211e3ee679..f3c326e3c324 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7027,7 +7027,8 @@ static inline int u64_shl_div_u64(u64 a, unsigned int shift,
 	return 0;
 }
 
-static int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc)
+static int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
+			    bool *expired)
 {
 	struct vcpu_vmx *vmx;
 	u64 tscl, guest_tscl, delta_tsc, lapic_timer_advance_cycles;
@@ -7066,7 +7067,8 @@ static int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc)
 		return -ERANGE;
 
 	vmx->hv_deadline_tsc = tscl + delta_tsc;
-	return delta_tsc == 0;
+	*expired = !delta_tsc;
+	return 0;
 }
 
 static void vmx_cancel_hv_timer(struct kvm_vcpu *vcpu)
-- 
2.21.0


  parent reply	other threads:[~2019-04-16 20:32 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-16 20:32 [PATCH v3 0/9] KVM: lapic: Fix a variety of timer adv issues Sean Christopherson
2019-04-16 20:32 ` [PATCH v3 1/9] KVM: lapic: Hard cap the auto-calculated timer advancement Sean Christopherson
2019-04-17 12:57   ` Paolo Bonzini
2019-04-17 14:34     ` Sean Christopherson
2019-04-17 15:00       ` Paolo Bonzini
2019-04-16 20:32 ` [PATCH v3 2/9] KVM: lapic: Convert guest TSC to host time domain when delaying Sean Christopherson
2019-04-17 12:56   ` Paolo Bonzini
2019-04-17 14:33     ` Sean Christopherson
2019-04-17 15:05       ` Paolo Bonzini
2019-04-16 20:32 ` [PATCH v3 3/9] KVM: lapic: Track lapic timer advance per vCPU Sean Christopherson
2019-04-16 20:32 ` [PATCH v3 4/9] KVM: lapic: Allow user to disable auto-tuning of timer advancement Sean Christopherson
2019-04-17 12:59   ` Paolo Bonzini
2019-04-17 15:22     ` Sean Christopherson
2019-04-16 20:32 ` [PATCH v3 5/9] KVM: lapic: Busy wait for timer to expire when using hv_timer Sean Christopherson
2019-04-16 20:32 ` [PATCH v3 6/9] KVM: lapic: Explicitly cancel the hv timer if it's pre-expired Sean Christopherson
2019-04-16 20:32 ` Sean Christopherson [this message]
2019-04-17 13:02   ` [PATCH v3 7/9] KVM: lapic: Refactor ->set_hv_timer to use an explicit expired param Paolo Bonzini
2019-04-16 20:32 ` [PATCH v3 8/9] KVM: lapic: Check for a pending timer intr prior to start_hv_timer() Sean Christopherson
2019-04-16 20:32 ` [PATCH v3 9/9] KVM: VMX: Skip delta_tsc shift-and-divide if the dividend is zero Sean Christopherson
2019-04-17 13:06 ` [PATCH v3 0/9] KVM: lapic: Fix a variety of timer adv issues Paolo Bonzini

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