| Message ID | 20170717142718.13853-7-cdall@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17/07/17 15:27, Christoffer Dall wrote: > We are about to add an additional soft timer to the arch timer state for > a VCPU and would like to be able to reuse the functions to program and > cancel a timer, so we make them slightly more generic and rename to make > it more clear that these functions work on soft timers and not the > hardware resource that this code is managing. > > Signed-off-by: Christoffer Dall <cdall@linaro.org> > --- > virt/kvm/arm/arch_timer.c | 33 ++++++++++++++++----------------- > 1 file changed, 16 insertions(+), 17 deletions(-) > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > index 8e89d63..871d8ae 100644 > --- a/virt/kvm/arm/arch_timer.c > +++ b/virt/kvm/arm/arch_timer.c > @@ -56,26 +56,22 @@ u64 kvm_phys_timer_read(void) > return timecounter->cc->read(timecounter->cc); > } > > -static bool timer_is_armed(struct arch_timer_cpu *timer) > +static bool soft_timer_is_armed(struct arch_timer_cpu *timer) > { > return timer->armed; > } > > -/* timer_arm: as in "arm the timer", not as in ARM the company */ > -static void timer_arm(struct arch_timer_cpu *timer, u64 ns) > +static void soft_timer_start(struct hrtimer *hrt, u64 ns) I find it a bit confusing that the soft_timer_* functions operate on different object types: arch_timer_cpu for soft_timer_is_armed(), and hrtimer for soft_timer_start. Is there anything that prevents us from keeping arch_timer_cpu for all of them? > { > - timer->armed = true; > - hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns), > + hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns), > HRTIMER_MODE_ABS); > } > > -static void timer_disarm(struct arch_timer_cpu *timer) > +static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work) > { > - if (timer_is_armed(timer)) { > - hrtimer_cancel(&timer->timer); > - cancel_work_sync(&timer->expired); > - timer->armed = false; > - } > + hrtimer_cancel(hrt); > + if (work) > + cancel_work_sync(work); > } > > static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) > @@ -271,7 +267,7 @@ static void kvm_timer_emulate(struct kvm_vcpu *vcpu, > return; > > /* The timer has not yet expired, schedule a background timer */ > - timer_arm(timer, kvm_timer_compute_delta(timer_ctx)); > + soft_timer_start(&timer->timer, kvm_timer_compute_delta(timer_ctx)); > } > > /* > @@ -285,7 +281,7 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) > struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); > struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); > > - BUG_ON(timer_is_armed(timer)); > + BUG_ON(soft_timer_is_armed(timer)); > > /* > * No need to schedule a background timer if any guest timer has > @@ -306,13 +302,16 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) > * The guest timers have not yet expired, schedule a background timer. > * Set the earliest expiration time among the guest timers. > */ > - timer_arm(timer, kvm_timer_earliest_exp(vcpu)); > + timer->armed = true; > + soft_timer_start(&timer->timer, kvm_timer_earliest_exp(vcpu)); > } > > void kvm_timer_unschedule(struct kvm_vcpu *vcpu) > { > struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > - timer_disarm(timer); > + > + soft_timer_cancel(&timer->timer, &timer->expired); > + timer->armed = false; > } > > static void kvm_timer_flush_hwstate_vgic(struct kvm_vcpu *vcpu) > @@ -448,7 +447,7 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) > * This is to cancel the background timer for the physical timer > * emulation if it is set. > */ > - timer_disarm(timer); > + soft_timer_cancel(&timer->timer, &timer->expired); > > /* > * The guest could have modified the timer registers or the timer > @@ -615,7 +614,7 @@ 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); > > - timer_disarm(timer); > + soft_timer_cancel(&timer->timer, &timer->expired); > kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq); > } > > Otherwise looks good to me. Thanks, M.
On Tue, Aug 01, 2017 at 03:10:59PM +0100, Marc Zyngier wrote: > On 17/07/17 15:27, Christoffer Dall wrote: > > We are about to add an additional soft timer to the arch timer state for > > a VCPU and would like to be able to reuse the functions to program and > > cancel a timer, so we make them slightly more generic and rename to make > > it more clear that these functions work on soft timers and not the > > hardware resource that this code is managing. > > > > Signed-off-by: Christoffer Dall <cdall@linaro.org> > > --- > > virt/kvm/arm/arch_timer.c | 33 ++++++++++++++++----------------- > > 1 file changed, 16 insertions(+), 17 deletions(-) > > > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > > index 8e89d63..871d8ae 100644 > > --- a/virt/kvm/arm/arch_timer.c > > +++ b/virt/kvm/arm/arch_timer.c > > @@ -56,26 +56,22 @@ u64 kvm_phys_timer_read(void) > > return timecounter->cc->read(timecounter->cc); > > } > > > > -static bool timer_is_armed(struct arch_timer_cpu *timer) > > +static bool soft_timer_is_armed(struct arch_timer_cpu *timer) > > { > > return timer->armed; > > } > > > > -/* timer_arm: as in "arm the timer", not as in ARM the company */ > > -static void timer_arm(struct arch_timer_cpu *timer, u64 ns) > > +static void soft_timer_start(struct hrtimer *hrt, u64 ns) > > I find it a bit confusing that the soft_timer_* functions operate on > different object types: arch_timer_cpu for soft_timer_is_armed(), and > hrtimer for soft_timer_start. Is there anything that prevents us from > keeping arch_timer_cpu for all of them? > The problem is now we have two timers for a VCPU, one which is shared between the two timer contexts (physical and virtual) used when the process goes to sleep with a programmed timer, and one used to exit the guest for the physical timer emulation. So I either need to provide some sideband information or use the hrtimer pointer. I tried to address this in later patches by renaming timer_is_armed() to bg_timer_is_armed(), but I'm open to better suggestions. > > { > > - timer->armed = true; > > - hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns), > > + hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns), > > HRTIMER_MODE_ABS); > > } > > > > -static void timer_disarm(struct arch_timer_cpu *timer) > > +static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work) > > { > > - if (timer_is_armed(timer)) { > > - hrtimer_cancel(&timer->timer); > > - cancel_work_sync(&timer->expired); > > - timer->armed = false; > > - } > > + hrtimer_cancel(hrt); > > + if (work) > > + cancel_work_sync(work); > > } > > > > static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) > > @@ -271,7 +267,7 @@ static void kvm_timer_emulate(struct kvm_vcpu *vcpu, > > return; > > > > /* The timer has not yet expired, schedule a background timer */ > > - timer_arm(timer, kvm_timer_compute_delta(timer_ctx)); > > + soft_timer_start(&timer->timer, kvm_timer_compute_delta(timer_ctx)); > > } > > > > /* > > @@ -285,7 +281,7 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) > > struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); > > struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); > > > > - BUG_ON(timer_is_armed(timer)); > > + BUG_ON(soft_timer_is_armed(timer)); > > > > /* > > * No need to schedule a background timer if any guest timer has > > @@ -306,13 +302,16 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) > > * The guest timers have not yet expired, schedule a background timer. > > * Set the earliest expiration time among the guest timers. > > */ > > - timer_arm(timer, kvm_timer_earliest_exp(vcpu)); > > + timer->armed = true; > > + soft_timer_start(&timer->timer, kvm_timer_earliest_exp(vcpu)); > > } > > > > void kvm_timer_unschedule(struct kvm_vcpu *vcpu) > > { > > struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > > - timer_disarm(timer); > > + > > + soft_timer_cancel(&timer->timer, &timer->expired); > > + timer->armed = false; > > } > > > > static void kvm_timer_flush_hwstate_vgic(struct kvm_vcpu *vcpu) > > @@ -448,7 +447,7 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) > > * This is to cancel the background timer for the physical timer > > * emulation if it is set. > > */ > > - timer_disarm(timer); > > + soft_timer_cancel(&timer->timer, &timer->expired); > > > > /* > > * The guest could have modified the timer registers or the timer > > @@ -615,7 +614,7 @@ 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); > > > > - timer_disarm(timer); > > + soft_timer_cancel(&timer->timer, &timer->expired); > > kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq); > > } > > > > > > Otherwise looks good to me. > Thanks! -Christoffer
On 01/08/17 15:57, Christoffer Dall wrote: > On Tue, Aug 01, 2017 at 03:10:59PM +0100, Marc Zyngier wrote: >> On 17/07/17 15:27, Christoffer Dall wrote: >>> We are about to add an additional soft timer to the arch timer state for >>> a VCPU and would like to be able to reuse the functions to program and >>> cancel a timer, so we make them slightly more generic and rename to make >>> it more clear that these functions work on soft timers and not the >>> hardware resource that this code is managing. >>> >>> Signed-off-by: Christoffer Dall <cdall@linaro.org> >>> --- >>> virt/kvm/arm/arch_timer.c | 33 ++++++++++++++++----------------- >>> 1 file changed, 16 insertions(+), 17 deletions(-) >>> >>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c >>> index 8e89d63..871d8ae 100644 >>> --- a/virt/kvm/arm/arch_timer.c >>> +++ b/virt/kvm/arm/arch_timer.c >>> @@ -56,26 +56,22 @@ u64 kvm_phys_timer_read(void) >>> return timecounter->cc->read(timecounter->cc); >>> } >>> >>> -static bool timer_is_armed(struct arch_timer_cpu *timer) >>> +static bool soft_timer_is_armed(struct arch_timer_cpu *timer) >>> { >>> return timer->armed; >>> } >>> >>> -/* timer_arm: as in "arm the timer", not as in ARM the company */ >>> -static void timer_arm(struct arch_timer_cpu *timer, u64 ns) >>> +static void soft_timer_start(struct hrtimer *hrt, u64 ns) >> >> I find it a bit confusing that the soft_timer_* functions operate on >> different object types: arch_timer_cpu for soft_timer_is_armed(), and >> hrtimer for soft_timer_start. Is there anything that prevents us from >> keeping arch_timer_cpu for all of them? >> > > The problem is now we have two timers for a VCPU, one which is shared > between the two timer contexts (physical and virtual) used when the > process goes to sleep with a programmed timer, and one used to exit the > guest for the physical timer emulation. So I either need to provide > some sideband information or use the hrtimer pointer. Yes, I came to the same conclusion at while reading patch 8. > I tried to address this in later patches by renaming timer_is_armed() to > bg_timer_is_armed(), but I'm open to better suggestions. Bah, never mind. Thanks, M.
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 8e89d63..871d8ae 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -56,26 +56,22 @@ u64 kvm_phys_timer_read(void) return timecounter->cc->read(timecounter->cc); } -static bool timer_is_armed(struct arch_timer_cpu *timer) +static bool soft_timer_is_armed(struct arch_timer_cpu *timer) { return timer->armed; } -/* timer_arm: as in "arm the timer", not as in ARM the company */ -static void timer_arm(struct arch_timer_cpu *timer, u64 ns) +static void soft_timer_start(struct hrtimer *hrt, u64 ns) { - timer->armed = true; - hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns), + hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns), HRTIMER_MODE_ABS); } -static void timer_disarm(struct arch_timer_cpu *timer) +static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work) { - if (timer_is_armed(timer)) { - hrtimer_cancel(&timer->timer); - cancel_work_sync(&timer->expired); - timer->armed = false; - } + hrtimer_cancel(hrt); + if (work) + cancel_work_sync(work); } static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) @@ -271,7 +267,7 @@ static void kvm_timer_emulate(struct kvm_vcpu *vcpu, return; /* The timer has not yet expired, schedule a background timer */ - timer_arm(timer, kvm_timer_compute_delta(timer_ctx)); + soft_timer_start(&timer->timer, kvm_timer_compute_delta(timer_ctx)); } /* @@ -285,7 +281,7 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); - BUG_ON(timer_is_armed(timer)); + BUG_ON(soft_timer_is_armed(timer)); /* * No need to schedule a background timer if any guest timer has @@ -306,13 +302,16 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu) * The guest timers have not yet expired, schedule a background timer. * Set the earliest expiration time among the guest timers. */ - timer_arm(timer, kvm_timer_earliest_exp(vcpu)); + timer->armed = true; + soft_timer_start(&timer->timer, kvm_timer_earliest_exp(vcpu)); } void kvm_timer_unschedule(struct kvm_vcpu *vcpu) { struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; - timer_disarm(timer); + + soft_timer_cancel(&timer->timer, &timer->expired); + timer->armed = false; } static void kvm_timer_flush_hwstate_vgic(struct kvm_vcpu *vcpu) @@ -448,7 +447,7 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) * This is to cancel the background timer for the physical timer * emulation if it is set. */ - timer_disarm(timer); + soft_timer_cancel(&timer->timer, &timer->expired); /* * The guest could have modified the timer registers or the timer @@ -615,7 +614,7 @@ 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); - timer_disarm(timer); + soft_timer_cancel(&timer->timer, &timer->expired); kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq); }
We are about to add an additional soft timer to the arch timer state for a VCPU and would like to be able to reuse the functions to program and cancel a timer, so we make them slightly more generic and rename to make it more clear that these functions work on soft timers and not the hardware resource that this code is managing. Signed-off-by: Christoffer Dall <cdall@linaro.org> --- virt/kvm/arm/arch_timer.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-)