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From: Jinyu Tang <jinyu.tang@linux.dev>
To: Anup Patel <anup@brainfault.org>,
	Anup Patel <apatel@ventanamicro.com>,
	Atish Patra <atish.patra@linux.dev>
Cc: kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Nutty Liu <nutty.liu@hotmail.com>, Jinyu Tang <tjytimi@163.com>,
	Jinyu Tang <jinyu.tang@linux.dev>
Subject: [PATCH] KVM: riscv: Avoid redundant interrupt check for pending timers
Date: Fri, 14 Aug 2026 08:35:41 -0400	[thread overview]
Message-ID: <20260814123541.593613-1-jinyu.tang@linux.dev> (raw)

kvm_vcpu_check_block() calls kvm_arch_vcpu_runnable() before
checking whether a timer is pending. On RISC-V, kvm_arch_vcpu_runnable()
already checks all pending guest interrupts through
kvm_riscv_vcpu_has_interrupts(vcpu, -1UL), including IRQ_VS_TIMER.

Drop the repeated IRQ_VS_TIMER pending-interrupt check from
kvm_riscv_vcpu_timer_pending() and keep the helper focused on the timer
deadline state. If the timer becomes pending after the runnable check,
the timer path still injects IRQ_VS_TIMER and kicks the vCPU through the
normal wakeup path.

Signed-off-by: Jinyu Tang <jinyu.tang@linux.dev>
---
 arch/riscv/kvm/vcpu_timer.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index ae53133c7ab0..0e01bd793772 100644
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -132,11 +132,7 @@ bool kvm_riscv_vcpu_timer_pending(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_timer *t = &vcpu->arch.timer;
 	struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
 
-	if (!kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t) ||
-	    kvm_riscv_vcpu_has_interrupts(vcpu, 1UL << IRQ_VS_TIMER))
-		return true;
-	else
-		return false;
+	return !kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t);
 }
 
 static void kvm_riscv_vcpu_timer_blocking(struct kvm_vcpu *vcpu)
-- 
2.43.0


WARNING: multiple messages have this Message-ID (diff)
From: Jinyu Tang <jinyu.tang@linux.dev>
To: Anup Patel <anup@brainfault.org>,
	Anup Patel <apatel@ventanamicro.com>,
	Atish Patra <atish.patra@linux.dev>
Cc: kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Nutty Liu <nutty.liu@hotmail.com>, Jinyu Tang <tjytimi@163.com>,
	Jinyu Tang <jinyu.tang@linux.dev>
Subject: [PATCH] KVM: riscv: Avoid redundant interrupt check for pending timers
Date: Fri, 14 Aug 2026 08:35:41 -0400	[thread overview]
Message-ID: <20260814123541.593613-1-jinyu.tang@linux.dev> (raw)

kvm_vcpu_check_block() calls kvm_arch_vcpu_runnable() before
checking whether a timer is pending. On RISC-V, kvm_arch_vcpu_runnable()
already checks all pending guest interrupts through
kvm_riscv_vcpu_has_interrupts(vcpu, -1UL), including IRQ_VS_TIMER.

Drop the repeated IRQ_VS_TIMER pending-interrupt check from
kvm_riscv_vcpu_timer_pending() and keep the helper focused on the timer
deadline state. If the timer becomes pending after the runnable check,
the timer path still injects IRQ_VS_TIMER and kicks the vCPU through the
normal wakeup path.

Signed-off-by: Jinyu Tang <jinyu.tang@linux.dev>
---
 arch/riscv/kvm/vcpu_timer.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index ae53133c7ab0..0e01bd793772 100644
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -132,11 +132,7 @@ bool kvm_riscv_vcpu_timer_pending(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_timer *t = &vcpu->arch.timer;
 	struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
 
-	if (!kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t) ||
-	    kvm_riscv_vcpu_has_interrupts(vcpu, 1UL << IRQ_VS_TIMER))
-		return true;
-	else
-		return false;
+	return !kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t);
 }
 
 static void kvm_riscv_vcpu_timer_blocking(struct kvm_vcpu *vcpu)
-- 
2.43.0


-- 
kvm-riscv mailing list
kvm-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kvm-riscv

WARNING: multiple messages have this Message-ID (diff)
From: Jinyu Tang <jinyu.tang@linux.dev>
To: Anup Patel <anup@brainfault.org>,
	Anup Patel <apatel@ventanamicro.com>,
	Atish Patra <atish.patra@linux.dev>
Cc: kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Nutty Liu <nutty.liu@hotmail.com>, Jinyu Tang <tjytimi@163.com>,
	Jinyu Tang <jinyu.tang@linux.dev>
Subject: [PATCH] KVM: riscv: Avoid redundant interrupt check for pending timers
Date: Fri, 14 Aug 2026 08:35:41 -0400	[thread overview]
Message-ID: <20260814123541.593613-1-jinyu.tang@linux.dev> (raw)

kvm_vcpu_check_block() calls kvm_arch_vcpu_runnable() before
checking whether a timer is pending. On RISC-V, kvm_arch_vcpu_runnable()
already checks all pending guest interrupts through
kvm_riscv_vcpu_has_interrupts(vcpu, -1UL), including IRQ_VS_TIMER.

Drop the repeated IRQ_VS_TIMER pending-interrupt check from
kvm_riscv_vcpu_timer_pending() and keep the helper focused on the timer
deadline state. If the timer becomes pending after the runnable check,
the timer path still injects IRQ_VS_TIMER and kicks the vCPU through the
normal wakeup path.

Signed-off-by: Jinyu Tang <jinyu.tang@linux.dev>
---
 arch/riscv/kvm/vcpu_timer.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index ae53133c7ab0..0e01bd793772 100644
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -132,11 +132,7 @@ bool kvm_riscv_vcpu_timer_pending(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_timer *t = &vcpu->arch.timer;
 	struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
 
-	if (!kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t) ||
-	    kvm_riscv_vcpu_has_interrupts(vcpu, 1UL << IRQ_VS_TIMER))
-		return true;
-	else
-		return false;
+	return !kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t);
 }
 
 static void kvm_riscv_vcpu_timer_blocking(struct kvm_vcpu *vcpu)
-- 
2.43.0


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

             reply	other threads:[~2026-08-14 12:36 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-14 12:35 Jinyu Tang [this message]
2026-08-14 12:35 ` [PATCH] KVM: riscv: Avoid redundant interrupt check for pending timers Jinyu Tang
2026-08-14 12:35 ` Jinyu Tang
2026-08-14 12:52 ` sashiko-bot

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