Recomputing the whole GIC state when injecting a single interrupt
is a tiny bit silly.
Instead, just computing the new state for this particular IRQ saves
a bit of processing and makes things noticeably faster.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/include/asm/kvm_vgic.h | 1 +
arch/arm/kvm/vgic.c | 69 ++++++++++++++++++++++++++++++-----------
2 files changed, 52 insertions(+), 18 deletions(-)
diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
index 633e697..1f7fd32 100644
--- a/arch/arm/include/asm/kvm_vgic.h
+++ b/arch/arm/include/asm/kvm_vgic.h
@@ -183,6 +183,7 @@ struct vgic_dist {
u8 irq_sgi_sources[VGIC_MAX_CPUS][16];
/* Target CPU for each IRQ */
+ u8 irq_spi_cpu[VGIC_NR_SHARED_IRQS];
struct vgic_bitmap irq_spi_target[VGIC_MAX_CPUS];
/* Bitmap indicating which CPU has something pending */
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 5177792..5f32772 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -47,6 +47,9 @@
* registers, stored on each vcpu. We only keep one bit of
* information per interrupt, making sure that only one vcpu can
* accept the interrupt.
+ * The same is true when injecting an interrupt, except that we only
+ * consider a single interrupt at a time. The irq_spi_cpu array
+ * contains the target CPU for each SPI.
*
* The handling of level interrupts adds some extra complexity. We
* need to track when the interrupt has been EOIed, so we can sample
@@ -313,6 +316,7 @@ static void vgic_set_target_reg(struct kvm *kvm, u32 val, int irq)
int shift = i * 8;
target = ffs((val >> shift) & 0xffU);
target = target ? (target - 1) : 0;
+ dist->irq_spi_cpu[irq] = target;
kvm_for_each_vcpu(c, vcpu, kvm) {
bmap = vgic_bitmap_get_shared_map(&dist->irq_spi_target[c]);
if (c == target)
@@ -866,23 +870,19 @@ static void vgic_kick_vcpus(struct kvm *kvm)
}
}
-int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, const struct kvm_irq_level *irq)
+static bool vgic_update_irq_state(struct kvm *kvm, int cpuid,
+ const struct kvm_irq_level *irq)
{
struct vgic_dist *dist = &kvm->arch.vgic;
- int nrcpus = atomic_read(&kvm->online_vcpus);
- int is_edge, state;
+ struct kvm_vcpu *vcpu;
+ int is_edge, state, level;
+ int pend, enabled;
unsigned long flags;
- bool updated_state = false;
- if (cpuid >= nrcpus)
- return -EINVAL;
-
- /* Only PPIs or SPIs */
- if (irq->irq >= VGIC_NR_IRQS || irq->irq < 16)
- return -EINVAL;
+ level = !!irq->level;
- kvm_debug("Inject IRQ%d\n", irq->irq);
spin_lock_irqsave(&dist->lock, flags);
+
is_edge = vgic_irq_is_edge(dist, irq->irq);
state = vgic_bitmap_get_irq_val(&dist->irq_state, cpuid, irq->irq);
@@ -891,16 +891,49 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, const struct kvm_irq_level *
* - level triggered and we change level
* - edge triggered and we have a rising edge
*/
- if ((!is_edge && (state ^ !!irq->level)) ||
- (is_edge && !state && irq->level)) {
- vgic_bitmap_set_irq_val(&dist->irq_state, cpuid,
- irq->irq, !!irq->level);
- vgic_update_state(kvm);
- updated_state = true;
+ if (!((!is_edge && (state ^ level)) ||
+ (is_edge && !state && level))) {
+ spin_unlock_irqrestore(&dist->lock, flags);
+ return false;
+ }
+
+ vgic_bitmap_set_irq_val(&dist->irq_state, cpuid, irq->irq, level);
+
+ enabled = vgic_bitmap_get_irq_val(&dist->irq_enabled, cpuid, irq->irq);
+ pend = level && enabled;
+
+ if (irq->irq >= 32) {
+ cpuid = dist->irq_spi_cpu[irq->irq - 32];
+ pend &= vgic_bitmap_get_irq_val(&dist->irq_spi_target[cpuid],
+ 0, irq->irq);
}
+
+ kvm_debug("Inject IRQ%d level %d CPU%d\n", irq->irq, level, cpuid);
+
+ vcpu = kvm_get_vcpu(kvm, cpuid);
+ if (pend) {
+ set_bit(irq->irq, vcpu->arch.vgic_cpu.pending);
+ set_bit(cpuid, &dist->irq_pending_on_cpu);
+ } else
+ clear_bit(irq->irq, vcpu->arch.vgic_cpu.pending);
+
spin_unlock_irqrestore(&dist->lock, flags);
- if (updated_state)
+ return true;
+}
+
+int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, const struct kvm_irq_level *irq)
+{
+ int nrcpus = atomic_read(&kvm->online_vcpus);
+
+ if (cpuid >= nrcpus)
+ return -EINVAL;
+
+ /* Only PPIs or SPIs */
+ if (irq->irq >= VGIC_NR_IRQS || irq->irq < 16)
+ return -EINVAL;
+
+ if (vgic_update_irq_state(kvm, cpuid, irq))
vgic_kick_vcpus(kvm);
return 0;
--
1.7.12
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