The timer code makes use of a per-timer irq level cache, which
looks like a very minor optimisation to avoid taking a lock upon
updating the GIC view of the interrupt when it is unchanged from
the previous state.
This is coming in the way of more important correctness issues,
so get rid of the cache, which simplifies a couple of minor things.
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/kvm/arch_timer.c | 20 +++++++++-----------
include/kvm/arm_arch_timer.h | 5 -----
2 files changed, 9 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 22e79ecb34bc4..5cfe223da2996 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -445,9 +445,8 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
{
kvm_timer_update_status(timer_ctx, new_level);
- timer_ctx->irq.level = new_level;
trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_irq(timer_ctx),
- timer_ctx->irq.level);
+ new_level);
if (userspace_irqchip(vcpu->kvm))
return;
@@ -465,7 +464,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
kvm_vgic_inject_irq(vcpu->kvm, vcpu,
timer_irq(timer_ctx),
- timer_ctx->irq.level,
+ new_level,
timer_ctx);
}
@@ -476,10 +475,7 @@ static void timer_emulate(struct arch_timer_context *ctx)
trace_kvm_timer_emulate(ctx, pending);
- if (pending != ctx->irq.level)
- kvm_timer_update_irq(timer_context_to_vcpu(ctx), pending, ctx);
-
- kvm_timer_update_status(ctx, pending);
+ kvm_timer_update_irq(timer_context_to_vcpu(ctx), pending, ctx);
/*
* If the timer can fire now, we don't need to have a soft timer
@@ -676,6 +672,7 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
{
struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
+ bool pending = kvm_timer_pending(ctx);
bool phys_active = false;
/*
@@ -684,12 +681,12 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
* this point and the register restoration, we'll take the
* interrupt anyway.
*/
- kvm_timer_update_irq(vcpu, kvm_timer_pending(ctx), ctx);
+ kvm_timer_update_irq(vcpu, pending, ctx);
if (irqchip_in_kernel(vcpu->kvm))
phys_active = kvm_vgic_map_is_active(vcpu, timer_irq(ctx));
- phys_active |= ctx->irq.level;
+ phys_active |= pending;
phys_active |= vgic_is_v5(vcpu->kvm);
set_timer_irq_phys_active(ctx, phys_active);
@@ -698,6 +695,7 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
{
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
+ bool pending = kvm_timer_pending(vtimer);
/*
* Update the timer output so that it is likely to match the
@@ -705,7 +703,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
* this point and the register restoration, we'll take the
* interrupt anyway.
*/
- kvm_timer_update_irq(vcpu, kvm_timer_pending(vtimer), vtimer);
+ kvm_timer_update_irq(vcpu, pending, vtimer);
/*
* When using a userspace irqchip with the architected timers and a
@@ -717,7 +715,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
* being de-asserted, we unmask the interrupt again so that we exit
* from the guest when the timer fires.
*/
- if (vtimer->irq.level)
+ if (pending)
disable_percpu_irq(host_vtimer_irq);
else
enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index bf8cc9589bd09..2c26d457c3510 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -66,11 +66,6 @@ struct arch_timer_context {
*/
bool loaded;
- /* Output level of the timer IRQ */
- struct {
- bool level;
- } irq;
-
/* Who am I? */
enum kvm_arch_timers timer_id;
--
2.47.3