From 9b6022b8f7b2f9c32b55887ceef7835ccedc4416 Mon Sep 17 00:00:00 2001 From: Asias He Date: Sat, 7 May 2011 10:34:20 +0800 Subject: [PATCH] kvm tools: Respect VRING_AVAIL_F_NO_INTERRUPT Do not inject IRQ when guest suppress it. This can reduce IRQ injection further and bumps host to guest bandwitdh to 6178.78 Mbps(cpu 63.96%). Signed-off-by: Asias He Signed-off-by: Pekka Enberg --- virtio/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/virtio/core.c b/virtio/core.c index 0734984..2b3503d 100644 --- a/virtio/core.c +++ b/virtio/core.c @@ -60,6 +60,9 @@ u16 virt_queue__get_iov(struct virt_queue *queue, struct iovec iov[], u16 *out, void virt_queue__trigger_irq(struct virt_queue *vq, int irq, u8 *isr, struct kvm *kvm) { + if (vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) + return; + if (*isr == VIRTIO_IRQ_LOW) { *isr = VIRTIO_IRQ_HIGH; kvm__irq_line(kvm, irq, VIRTIO_IRQ_HIGH);