From 26b9b5fe17cc1b6be2e8bf8b9d16094f420bb8ad Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 6 Aug 2012 15:26:14 +0200 Subject: [PATCH] virtio: fix vhost handling Commit b1f416aa8d870fab71030abc9401cfc77b948e8e breaks vhost_net because it always registers the virtio_pci_host_notifier_read() handler function on the ioeventfd, even when vhost_net.ko is using the ioeventfd. The result is both QEMU and vhost_net.ko polling on the same eventfd and the virtio_net.ko guest driver seeing inconsistent results: # ifconfig eth0 192.168.0.1 netmask 255.255.255.0 virtio_net virtio0: output:id 0 is not a head! To fix this, proceed the same as we do for irqfd: add a parameter to virtio_queue_set_host_notifier_fd_handler and in that case only set the notifier, not the handler. Cc: Stefan Hajnoczi Tested-by: Stefan Hajnoczi Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Signed-off-by: Anthony Liguori --- hw/virtio-pci.c | 14 +++++++------- hw/virtio.c | 7 +++++-- hw/virtio.h | 3 ++- 3 files changed, 14 insertions(+), 10 deletions(-) diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c index 3ab9747..125eded 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -160,7 +160,7 @@ static int virtio_pci_load_queue(void * opaque, int n, QEMUFile *f) } static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy, - int n, bool assign) + int n, bool assign, bool set_handler) { VirtQueue *vq = virtio_get_queue(proxy->vdev, n); EventNotifier *notifier = virtio_queue_get_host_notifier(vq); @@ -173,13 +173,13 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy, __func__, r); return r; } - virtio_queue_set_host_notifier_fd_handler(vq, true); + virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler); memory_region_add_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2, true, n, notifier); } else { memory_region_del_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2, true, n, notifier); - virtio_queue_set_host_notifier_fd_handler(vq, false); + virtio_queue_set_host_notifier_fd_handler(vq, false, false); event_notifier_cleanup(notifier); } return r; @@ -200,7 +200,7 @@ static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy) continue; } - r = virtio_pci_set_host_notifier_internal(proxy, n, true); + r = virtio_pci_set_host_notifier_internal(proxy, n, true, true); if (r < 0) { goto assign_error; } @@ -214,7 +214,7 @@ assign_error: continue; } - r = virtio_pci_set_host_notifier_internal(proxy, n, false); + r = virtio_pci_set_host_notifier_internal(proxy, n, false, false); assert(r >= 0); } proxy->ioeventfd_started = false; @@ -235,7 +235,7 @@ static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy) continue; } - r = virtio_pci_set_host_notifier_internal(proxy, n, false); + r = virtio_pci_set_host_notifier_internal(proxy, n, false, false); assert(r >= 0); } proxy->ioeventfd_started = false; @@ -683,7 +683,7 @@ static int virtio_pci_set_host_notifier(void *opaque, int n, bool assign) * currently only stops on status change away from ok, * reset, vmstop and such. If we do add code to start here, * need to check vmstate, device state etc. */ - return virtio_pci_set_host_notifier_internal(proxy, n, assign); + return virtio_pci_set_host_notifier_internal(proxy, n, assign, false); } static void virtio_pci_vmstate_change(void *opaque, bool running) diff --git a/hw/virtio.c b/hw/virtio.c index d146f86..209c763 100644 --- a/hw/virtio.c +++ b/hw/virtio.c @@ -1021,13 +1021,16 @@ static void virtio_queue_host_notifier_read(EventNotifier *n) } } -void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign) +void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign, + bool set_handler) { - if (assign) { + if (assign && set_handler) { event_notifier_set_handler(&vq->host_notifier, virtio_queue_host_notifier_read); } else { event_notifier_set_handler(&vq->host_notifier, NULL); + } + if (!assign) { /* Test and clear notifier before after disabling event, * in case poll callback didn't have time to run. */ virtio_queue_host_notifier_read(&vq->host_notifier); diff --git a/hw/virtio.h b/hw/virtio.h index f8b5535..7a4f564 100644 --- a/hw/virtio.h +++ b/hw/virtio.h @@ -233,7 +233,8 @@ EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, bool with_irqfd); EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); -void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign); +void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign, + bool set_handler); void virtio_queue_notify_vq(VirtQueue *vq); void virtio_irq(VirtQueue *vq); #endif -- 1.7.10.4