> -----Original Message----- > From: qemu-devel-bounces+arei.gonglei=huawei....@nongnu.org > [mailto:qemu-devel-bounces+arei.gonglei=huawei....@nongnu.org] On > Behalf Of Jason Wang > Sent: Friday, February 21, 2014 5:05 PM > To: aligu...@amazon.com; m...@redhat.com; qemu-devel@nongnu.org > Cc: Paolo Bonzini; Jason Wang > Subject: [Qemu-devel] [PATCH V2] virtio-net: calculate proper msix vectors on > init > > Currently, the default msix vectors for virtio-net-pci is 3 which is > obvious not suitable for multiqueue guest, so we depends on the user > or management tools to pass a correct vectors parameter. In fact, we > can simplifying this by calculate the number of vectors on init. > > Consider we have N queues, the number of vectors needed is 2*N + 2 > (plus one config interrupt and control vq). We didn't check whether or > not host support control vq because it was added unconditionally by > qemu to avoid breaking legacy guests such as Minix. > > Cc: Paolo Bonzini <pbonz...@redhat.com> > Cc: Michael S. Tsirkin <m...@redhat.com> > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > hw/virtio/virtio-pci.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 7b91841..3b3b0e2 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1416,7 +1416,8 @@ static const TypeInfo virtio_serial_pci_info = { > static Property virtio_net_properties[] = { > DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, > VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, false), > - DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3), > + DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, > + DEV_NVECTORS_UNSPECIFIED), > DEFINE_VIRTIO_NET_FEATURES(VirtIOPCIProxy, host_features), > DEFINE_NIC_PROPERTIES(VirtIONetPCI, vdev.nic_conf), > DEFINE_VIRTIO_NET_PROPERTIES(VirtIONetPCI, vdev.net_conf), > @@ -1428,6 +1429,11 @@ static int virtio_net_pci_init(VirtIOPCIProxy > *vpci_dev) > DeviceState *qdev = DEVICE(vpci_dev); > VirtIONetPCI *dev = VIRTIO_NET_PCI(vpci_dev); > DeviceState *vdev = DEVICE(&dev->vdev); > + VirtIONet *net = VIRTIO_NET(&dev->vdev); > + > + if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { > + vpci_dev->nvectors = 2 * MAX(net->nic_conf.queues, 1) + 2; > + } > > virtio_net_set_config_size(&dev->vdev, vpci_dev->host_features); > virtio_net_set_netclient_name(&dev->vdev, qdev->id, > -- > 1.8.3.2 >
Good catch. Reviewed-by: Gonglei <arei.gong...@huawei.com> Best regards, -Gonglei
