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authorChristoffer Dall <christoffer.dall@linaro.org>2015-11-24 16:23:05 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2015-11-24 18:07:40 +0100
commit0e3dfda91d9fe8e2c4d0b5d21434b173a241eeaf (patch)
tree0f976f6b44f4ded62834c26579d9265406531a8f /virt
parent7e16aa81f9f6a7cfe2287b788a7d62abc2880185 (diff)
downloadlinux-linaro-stable-0e3dfda91d9fe8e2c4d0b5d21434b173a241eeaf.tar.gz
KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active
We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/arch_timer.c28
-rw-r--r--virt/kvm/arm/vgic.c34
2 files changed, 39 insertions, 23 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 21a0ab2d8919..69bca185c471 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -221,17 +221,23 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
kvm_timer_update_state(vcpu);
/*
- * If we enter the guest with the virtual input level to the VGIC
- * asserted, then we have already told the VGIC what we need to, and
- * we don't need to exit from the guest until the guest deactivates
- * the already injected interrupt, so therefore we should set the
- * hardware active state to prevent unnecessary exits from the guest.
- *
- * Conversely, if the virtual input level is deasserted, then always
- * clear the hardware active state to ensure that hardware interrupts
- * from the timer triggers a guest exit.
- */
- if (timer->irq.level)
+ * If we enter the guest with the virtual input level to the VGIC
+ * asserted, then we have already told the VGIC what we need to, and
+ * we don't need to exit from the guest until the guest deactivates
+ * the already injected interrupt, so therefore we should set the
+ * hardware active state to prevent unnecessary exits from the guest.
+ *
+ * Also, if we enter the guest with the virtual timer interrupt active,
+ * then it must be active on the physical distributor, because we set
+ * the HW bit and the guest must be able to deactivate the virtual and
+ * physical interrupt at the same time.
+ *
+ * Conversely, if the virtual input level is deasserted and the virtual
+ * interrupt is not active, then always clear the hardware active state
+ * to ensure that hardware interrupts from the timer triggers a guest
+ * exit.
+ */
+ if (timer->irq.level || kvm_vgic_map_is_active(vcpu, timer->map))
phys_active = true;
else
phys_active = false;
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 533538385d5d..97e2c088e1e9 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1096,6 +1096,27 @@ static void vgic_retire_lr(int lr_nr, struct kvm_vcpu *vcpu)
vgic_set_lr(vcpu, lr_nr, vlr);
}
+static bool dist_active_irq(struct kvm_vcpu *vcpu)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ return test_bit(vcpu->vcpu_id, dist->irq_active_on_cpu);
+}
+
+bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, struct irq_phys_map *map)
+{
+ int i;
+
+ for (i = 0; i < vcpu->arch.vgic_cpu.nr_lr; i++) {
+ struct vgic_lr vlr = vgic_get_lr(vcpu, i);
+
+ if (vlr.irq == map->virt_irq && vlr.state & LR_STATE_ACTIVE)
+ return true;
+ }
+
+ return dist_active_irq(vcpu);
+}
+
/*
* An interrupt may have been disabled after being made pending on the
* CPU interface (the classic case is a timer running while we're
@@ -1248,7 +1269,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
* may have been serviced from another vcpu. In all cases,
* move along.
*/
- if (!kvm_vgic_vcpu_pending_irq(vcpu) && !kvm_vgic_vcpu_active_irq(vcpu))
+ if (!kvm_vgic_vcpu_pending_irq(vcpu) && !dist_active_irq(vcpu))
goto epilog;
/* SGIs */
@@ -1479,17 +1500,6 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
return test_bit(vcpu->vcpu_id, dist->irq_pending_on_cpu);
}
-int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu)
-{
- struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-
- if (!irqchip_in_kernel(vcpu->kvm))
- return 0;
-
- return test_bit(vcpu->vcpu_id, dist->irq_active_on_cpu);
-}
-
-
void vgic_kick_vcpus(struct kvm *kvm)
{
struct kvm_vcpu *vcpu;