From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53385) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLouT-0001h6-IB for qemu-devel@nongnu.org; Fri, 07 Mar 2014 02:09:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WLouL-0002eB-87 for qemu-devel@nongnu.org; Fri, 07 Mar 2014 02:09:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45634) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLouL-0002dn-0B for qemu-devel@nongnu.org; Fri, 07 Mar 2014 02:09:25 -0500 From: Jason Wang Date: Fri, 7 Mar 2014 15:09:07 +0800 Message-Id: <1394176147-12608-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH V3] virtio-net: calculate proper msix vectors on init List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: aliguori@amazon.com, mst@redhat.com, qemu-devel@nongnu.org Cc: Paolo Bonzini , Jason Wang 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 Cc: Michael S. Tsirkin Signed-off-by: Jason Wang --- Changes from V2: - add compat flag to avoid breaking the migration Changes from V1: - remove the debug line --- hw/virtio/virtio-pci.c | 8 +++++++- include/hw/i386/pc.h | 5 +++++ 2 files changed, 12 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, diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index 9010246..ea71d1c 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -270,6 +270,11 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); .driver = "PIIX4_PM",\ .property = "acpi-pci-hotplug-with-bridge-support",\ .value = "off",\ + },\ + {\ + .driver = "virtio-net-pci", \ + .property = "vectors",\ + .value = stringify(3),\ } #define PC_COMPAT_1_6 \ -- 1.8.3.2