From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50954) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T0Tyz-0004MR-Pr for qemu-devel@nongnu.org; Sun, 12 Aug 2012 04:57:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T0Tyx-0007KU-EX for qemu-devel@nongnu.org; Sun, 12 Aug 2012 04:57:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T0Tyx-0007KQ-64 for qemu-devel@nongnu.org; Sun, 12 Aug 2012 04:57:11 -0400 Date: Sun, 12 Aug 2012 11:58:12 +0300 From: "Michael S. Tsirkin" Message-ID: <20120812085812.GA5137@redhat.com> References: <1344264970-25242-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1344264970-25242-1-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH] virtio: fix vhost handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, Stefan Hajnoczi , avi@redhat.com On Mon, Aug 06, 2012 at 04:56:10PM +0200, Paolo Bonzini wrote: > 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 > Signed-off-by: Paolo Bonzini Acked-by: Michael S. Tsirkin Anthony, could you pick this bugfix up please? > --- > The patch is a bit different from what I posted before, > so I didn't add Stefan's *-by tags. > > hw/virtio-pci.c | 14 +++++++------- > hw/virtio.c | 7 +++++-- > hw/virtio.h | 3 ++- > 3 file modificati, 14 inserzioni(+), 10 rimozioni(-) > > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c > index 3ab9747..6133626 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..89e6d6f 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..d6a8ea3 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 > -- > 1.7.11.2 >