From: Christoffer Dall christoffer.dall@arm.com
mainline inclusion from mainline-v5.0-rc1 commit 8a411b060f820140e9894239fde5819bb213bef0 category: feature feature: bg_timer enhancement
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The use of a work queue in the hrtimer expire function for the bg_timer is a leftover from the time when we would inject interrupts when the bg_timer expired.
Since we are no longer doing that, we can instead call kvm_vcpu_wake_up() directly from the hrtimer function and remove all workqueue functionality from the arch timer code.
Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Hailiang Zhang zhang.zhanghailiang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- include/kvm/arm_arch_timer.h | 4 ---- virt/kvm/arm/arch_timer.c | 34 +++++++--------------------------- 2 files changed, 7 insertions(+), 31 deletions(-)
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 6502feb..3377135 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -21,7 +21,6 @@
#include <linux/clocksource.h> #include <linux/hrtimer.h> -#include <linux/workqueue.h>
struct arch_timer_context { /* Registers: control register, timer value */ @@ -52,9 +51,6 @@ struct arch_timer_cpu { /* Background timer used when the guest is not running */ struct hrtimer bg_timer;
- /* Work queued with the above timer expires */ - struct work_struct expired; - /* Physical timer emulation */ struct hrtimer phys_timer;
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 17cecc9..da261f5 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -70,11 +70,9 @@ static void soft_timer_start(struct hrtimer *hrt, u64 ns) HRTIMER_MODE_ABS); }
-static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work) +static void soft_timer_cancel(struct hrtimer *hrt) { hrtimer_cancel(hrt); - if (work) - cancel_work_sync(work); }
static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) @@ -102,23 +100,6 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) return IRQ_HANDLED; }
-/* - * Work function for handling the backup timer that we schedule when a vcpu is - * no longer running, but had a timer programmed to fire in the future. - */ -static void kvm_timer_inject_irq_work(struct work_struct *work) -{ - struct kvm_vcpu *vcpu; - - vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired); - - /* - * If the vcpu is blocked we want to wake it up so that it will see - * the timer has expired when entering the guest. - */ - kvm_vcpu_wake_up(vcpu); -} - static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx) { u64 cval, now; @@ -188,7 +169,7 @@ static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt) return HRTIMER_RESTART; }
- schedule_work(&timer->expired); + kvm_vcpu_wake_up(vcpu); return HRTIMER_NORESTART; }
@@ -300,7 +281,7 @@ static void phys_timer_emulate(struct kvm_vcpu *vcpu) * then we also don't need a soft timer. */ if (kvm_timer_should_fire(ptimer) || !kvm_timer_irq_can_fire(ptimer)) { - soft_timer_cancel(&timer->phys_timer, NULL); + soft_timer_cancel(&timer->phys_timer); return; }
@@ -426,7 +407,7 @@ void kvm_timer_unschedule(struct kvm_vcpu *vcpu)
vtimer_restore_state(vcpu);
- soft_timer_cancel(&timer->bg_timer, &timer->expired); + soft_timer_cancel(&timer->bg_timer); }
static void set_cntvoff(u64 cntvoff) @@ -544,7 +525,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) * In any case, we re-schedule the hrtimer for the physical timer when * coming back to the VCPU thread in kvm_timer_vcpu_load(). */ - soft_timer_cancel(&timer->phys_timer, NULL); + soft_timer_cancel(&timer->phys_timer);
/* * The kernel may decide to run userspace after calling vcpu_put, so @@ -637,7 +618,6 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) update_vtimer_cntvoff(vcpu, kvm_phys_timer_read()); vcpu_ptimer(vcpu)->cntvoff = 0;
- INIT_WORK(&timer->expired, kvm_timer_inject_irq_work); hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); timer->bg_timer.function = kvm_bg_timer_expire;
@@ -794,8 +774,8 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
- soft_timer_cancel(&timer->bg_timer, &timer->expired); - soft_timer_cancel(&timer->phys_timer, NULL); + soft_timer_cancel(&timer->bg_timer); + soft_timer_cancel(&timer->phys_timer); kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq); }