When the host fails to complete the shake hand due to various reasons. e.g, for PCI and MMIO, if 0 is written as the PFN, it implies the host has given up and simply don't take any action. Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> --- virtio/mmio.c | 14 ++++++++------ virtio/pci.c | 10 ++++++---- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/virtio/mmio.c b/virtio/mmio.c index f0af4bd..ba02358 100644 --- a/virtio/mmio.c +++ b/virtio/mmio.c @@ -188,12 +188,14 @@ static void virtio_mmio_config_out(struct kvm_cpu *vcpu, break; case VIRTIO_MMIO_QUEUE_PFN: val = ioport__read32(data); - virtio_mmio_init_ioeventfd(vmmio->kvm, vdev, vmmio->hdr.queue_sel); - vdev->ops->init_vq(vmmio->kvm, vmmio->dev, - vmmio->hdr.queue_sel, - vmmio->hdr.guest_page_size, - vmmio->hdr.queue_align, - val); + if (val) { + virtio_mmio_init_ioeventfd(vmmio->kvm, vdev, vmmio->hdr.queue_sel); + vdev->ops->init_vq(vmmio->kvm, vmmio->dev, + vmmio->hdr.queue_sel, + vmmio->hdr.guest_page_size, + vmmio->hdr.queue_align, + val); + } break; case VIRTIO_MMIO_QUEUE_NOTIFY: val = ioport__read32(data); diff --git a/virtio/pci.c b/virtio/pci.c index 4ce1111..3c694c2 100644 --- a/virtio/pci.c +++ b/virtio/pci.c @@ -271,10 +271,12 @@ static bool virtio_pci__io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 break; case VIRTIO_PCI_QUEUE_PFN: val = ioport__read32(data); - virtio_pci__init_ioeventfd(kvm, vdev, vpci->queue_selector); - vdev->ops->init_vq(kvm, vpci->dev, vpci->queue_selector, - 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT, - VIRTIO_PCI_VRING_ALIGN, val); + if (val) { + virtio_pci__init_ioeventfd(kvm, vdev, vpci->queue_selector); + vdev->ops->init_vq(kvm, vpci->dev, vpci->queue_selector, + 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT, + VIRTIO_PCI_VRING_ALIGN, val); + } break; case VIRTIO_PCI_QUEUE_SEL: vpci->queue_selector = ioport__read16(data); -- 2.13.6