From 5669655aafdb88a8797c74a989dd0c0ebb1349fa Mon Sep 17 00:00:00 2001 From: Victor Kaplansky Date: Thu, 18 Feb 2016 16:12:23 +0200 Subject: vhost-user interrupt management fixes Since guest_mask_notifier can not be used in vhost-user mode due to buffering implied by unix control socket, force use_mask_notifier on virtio devices of vhost-user interfaces, and send correct callfd to the guest at vhost start. Using guest_notifier_mask function in vhost-user case may break interrupt mask paradigm, because mask/unmask is not really done when returning from guest_notifier_mask call, instead message is posted in a unix socket, and processed later. Add an option boolean flag 'use_mask_notifier' to disable the use of guest_notifier_mask in virtio pci. Signed-off-by: Didier Pallard Signed-off-by: Victor Kaplansky Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/net/vhost_net.c | 15 +++++++++++++-- hw/virtio/vhost.c | 9 +++++++++ hw/virtio/virtio-pci.c | 14 ++++++++------ hw/virtio/virtio.c | 1 + include/hw/virtio/virtio.h | 1 + 5 files changed, 32 insertions(+), 8 deletions(-) diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index b2428324b3..6e1032fc18 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -284,8 +284,19 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, } for (i = 0; i < total_queues; i++) { - vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2); - } + struct vhost_net *net; + + net = get_vhost_net(ncs[i].peer); + vhost_net_set_vq_index(net, i * 2); + + /* Suppress the masking guest notifiers on vhost user + * because vhost user doesn't interrupt masking/unmasking + * properly. + */ + if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) { + dev->use_guest_notifier_mask = false; + } + } r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true); if (r < 0) { diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 9f8ac38ccf..72d0c9e9ae 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -875,6 +875,14 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, /* Clear and discard previous events if any. */ event_notifier_test_and_clear(&vq->masked_notifier); + /* Init vring in unmasked state, unless guest_notifier_mask + * will do it later. + */ + if (!vdev->use_guest_notifier_mask) { + /* TODO: check and handle errors. */ + vhost_virtqueue_mask(dev, vdev, idx, false); + } + return 0; fail_kick: @@ -1167,6 +1175,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, struct vhost_vring_file file; if (mask) { + assert(vdev->use_guest_notifier_mask); file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); } else { file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 5494ff4a49..440776c06c 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -806,7 +806,7 @@ static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs) /* If guest supports masking, set up irqfd now. * Otherwise, delay until unmasked in the frontend. */ - if (k->guest_notifier_mask) { + if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) { ret = kvm_virtio_pci_irqfd_use(proxy, queue_no, vector); if (ret < 0) { kvm_virtio_pci_vq_vector_release(proxy, vector); @@ -822,7 +822,7 @@ undo: if (vector >= msix_nr_vectors_allocated(dev)) { continue; } - if (k->guest_notifier_mask) { + if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) { kvm_virtio_pci_irqfd_release(proxy, queue_no, vector); } kvm_virtio_pci_vq_vector_release(proxy, vector); @@ -849,7 +849,7 @@ static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs) /* If guest supports masking, clean up irqfd now. * Otherwise, it was cleaned when masked in the frontend. */ - if (k->guest_notifier_mask) { + if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) { kvm_virtio_pci_irqfd_release(proxy, queue_no, vector); } kvm_virtio_pci_vq_vector_release(proxy, vector); @@ -882,7 +882,7 @@ static int virtio_pci_vq_vector_unmask(VirtIOPCIProxy *proxy, /* If guest supports masking, irqfd is already setup, unmask it. * Otherwise, set it up now. */ - if (k->guest_notifier_mask) { + if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) { k->guest_notifier_mask(vdev, queue_no, false); /* Test after unmasking to avoid losing events. */ if (k->guest_notifier_pending && @@ -905,7 +905,7 @@ static void virtio_pci_vq_vector_mask(VirtIOPCIProxy *proxy, /* If guest supports masking, keep irqfd but mask it. * Otherwise, clean it up now. */ - if (k->guest_notifier_mask) { + if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) { k->guest_notifier_mask(vdev, queue_no, true); } else { kvm_virtio_pci_irqfd_release(proxy, queue_no, vector); @@ -1022,7 +1022,9 @@ static int virtio_pci_set_guest_notifier(DeviceState *d, int n, bool assign, event_notifier_cleanup(notifier); } - if (!msix_enabled(&proxy->pci_dev) && vdc->guest_notifier_mask) { + if (!msix_enabled(&proxy->pci_dev) && + vdev->use_guest_notifier_mask && + vdc->guest_notifier_mask) { vdc->guest_notifier_mask(vdev, n, !assign); } diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 90f25451d0..e365960bd7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1677,6 +1677,7 @@ void virtio_init(VirtIODevice *vdev, const char *name, vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, vdev); vdev->device_endian = virtio_default_endian(); + vdev->use_guest_notifier_mask = true; } hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 108cdb0f48..c38a2fef04 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -90,6 +90,7 @@ struct VirtIODevice VMChangeStateEntry *vmstate; char *bus_name; uint8_t device_endian; + bool use_guest_notifier_mask; QLIST_HEAD(, VirtQueue) *vector_queues; }; -- cgit v1.2.1