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-rw-r--r--virt/kvm/arm/arch_timer.c116
1 files changed, 64 insertions, 52 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 70268c0bec79..70f4c30918eb 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -36,6 +36,8 @@ static struct timecounter *timecounter;
static unsigned int host_vtimer_irq;
static u32 host_vtimer_irq_flags;
+static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
+
static const struct kvm_irq_level default_ptimer_irq = {
.irq = 30,
.level = 1,
@@ -56,6 +58,12 @@ u64 kvm_phys_timer_read(void)
return timecounter->cc->read(timecounter->cc);
}
+static inline bool userspace_irqchip(struct kvm *kvm)
+{
+ return static_branch_unlikely(&userspace_irqchip_in_use) &&
+ unlikely(!irqchip_in_kernel(kvm));
+}
+
static void soft_timer_start(struct hrtimer *hrt, u64 ns)
{
hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
@@ -69,25 +77,6 @@ static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work)
cancel_work_sync(work);
}
-static void kvm_vtimer_update_mask_user(struct kvm_vcpu *vcpu)
-{
- struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
-
- /*
- * When using a userspace irqchip with the architected timers, we must
- * prevent continuously exiting from the guest, and therefore mask the
- * physical interrupt by disabling it on the host interrupt controller
- * when the virtual level is high, such that the guest can make
- * forward progress. Once we detect the output level being
- * de-asserted, we unmask the interrupt again so that we exit from the
- * guest when the timer fires.
- */
- if (vtimer->irq.level)
- disable_percpu_irq(host_vtimer_irq);
- else
- enable_percpu_irq(host_vtimer_irq, 0);
-}
-
static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
{
struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;
@@ -106,9 +95,9 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
if (kvm_timer_should_fire(vtimer))
kvm_timer_update_irq(vcpu, true, vtimer);
- if (static_branch_unlikely(&userspace_irqchip_in_use) &&
- unlikely(!irqchip_in_kernel(vcpu->kvm)))
- kvm_vtimer_update_mask_user(vcpu);
+ if (userspace_irqchip(vcpu->kvm) &&
+ !static_branch_unlikely(&has_gic_active_state))
+ disable_percpu_irq(host_vtimer_irq);
return IRQ_HANDLED;
}
@@ -290,8 +279,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq,
timer_ctx->irq.level);
- if (!static_branch_unlikely(&userspace_irqchip_in_use) ||
- likely(irqchip_in_kernel(vcpu->kvm))) {
+ if (!userspace_irqchip(vcpu->kvm)) {
ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
timer_ctx->irq.irq,
timer_ctx->irq.level,
@@ -350,12 +338,6 @@ static void kvm_timer_update_state(struct kvm_vcpu *vcpu)
phys_timer_emulate(vcpu);
}
-static void __timer_snapshot_state(struct arch_timer_context *timer)
-{
- timer->cnt_ctl = read_sysreg_el0(cntv_ctl);
- timer->cnt_cval = read_sysreg_el0(cntv_cval);
-}
-
static void vtimer_save_state(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
@@ -367,8 +349,10 @@ static void vtimer_save_state(struct kvm_vcpu *vcpu)
if (!vtimer->loaded)
goto out;
- if (timer->enabled)
- __timer_snapshot_state(vtimer);
+ if (timer->enabled) {
+ vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl);
+ vtimer->cnt_cval = read_sysreg_el0(cntv_cval);
+ }
/* Disable the virtual timer */
write_sysreg_el0(0, cntv_ctl);
@@ -460,23 +444,43 @@ static void set_cntvoff(u64 cntvoff)
kvm_call_hyp(__kvm_timer_set_cntvoff, low, high);
}
-static void kvm_timer_vcpu_load_vgic(struct kvm_vcpu *vcpu)
+static inline void set_vtimer_irq_phys_active(struct kvm_vcpu *vcpu, bool active)
+{
+ int r;
+ r = irq_set_irqchip_state(host_vtimer_irq, IRQCHIP_STATE_ACTIVE, active);
+ WARN_ON(r);
+}
+
+static void kvm_timer_vcpu_load_gic(struct kvm_vcpu *vcpu)
{
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
bool phys_active;
- int ret;
- phys_active = kvm_vgic_map_is_active(vcpu, vtimer->irq.irq);
-
- ret = irq_set_irqchip_state(host_vtimer_irq,
- IRQCHIP_STATE_ACTIVE,
- phys_active);
- WARN_ON(ret);
+ if (irqchip_in_kernel(vcpu->kvm))
+ phys_active = kvm_vgic_map_is_active(vcpu, vtimer->irq.irq);
+ else
+ phys_active = vtimer->irq.level;
+ set_vtimer_irq_phys_active(vcpu, phys_active);
}
-static void kvm_timer_vcpu_load_user(struct kvm_vcpu *vcpu)
+static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
{
- kvm_vtimer_update_mask_user(vcpu);
+ struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
+
+ /*
+ * When using a userspace irqchip with the architected timers and a
+ * host interrupt controller that doesn't support an active state, we
+ * must still prevent continuously exiting from the guest, and
+ * therefore mask the physical interrupt by disabling it on the host
+ * interrupt controller when the virtual level is high, such that the
+ * guest can make forward progress. Once we detect the output level
+ * being de-asserted, we unmask the interrupt again so that we exit
+ * from the guest when the timer fires.
+ */
+ if (vtimer->irq.level)
+ disable_percpu_irq(host_vtimer_irq);
+ else
+ enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
}
void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
@@ -487,10 +491,10 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
if (unlikely(!timer->enabled))
return;
- if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
- kvm_timer_vcpu_load_user(vcpu);
+ if (static_branch_likely(&has_gic_active_state))
+ kvm_timer_vcpu_load_gic(vcpu);
else
- kvm_timer_vcpu_load_vgic(vcpu);
+ kvm_timer_vcpu_load_nogic(vcpu);
set_cntvoff(vtimer->cntvoff);
@@ -555,18 +559,24 @@ static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)
{
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
- if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
- __timer_snapshot_state(vtimer);
- if (!kvm_timer_should_fire(vtimer)) {
- kvm_timer_update_irq(vcpu, false, vtimer);
- kvm_vtimer_update_mask_user(vcpu);
- }
+ if (!kvm_timer_should_fire(vtimer)) {
+ kvm_timer_update_irq(vcpu, false, vtimer);
+ if (static_branch_likely(&has_gic_active_state))
+ set_vtimer_irq_phys_active(vcpu, false);
+ else
+ enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
}
}
void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
{
- unmask_vtimer_irq_user(vcpu);
+ struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+
+ if (unlikely(!timer->enabled))
+ return;
+
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
+ unmask_vtimer_irq_user(vcpu);
}
int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
@@ -753,6 +763,8 @@ int kvm_timer_hyp_init(bool has_gic)
kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
goto out_free_irq;
}
+
+ static_branch_enable(&has_gic_active_state);
}
kvm_info("virtual timer IRQ%d\n", host_vtimer_irq);