From 51a81a2118df0c70988f00d61647da9e298483a4 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Mon, 8 Mar 2021 12:49:19 +0800 Subject: virtio-net: calculating proper msix vectors on init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 calculating the number of vectors on realize. Consider we have N queues, the number of vectors needed is 2*N + 2 (#queue pairs + 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. Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Stefan Hajnoczi Signed-off-by: Jason Wang --- hw/core/machine.c | 1 + hw/virtio/virtio-net-pci.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index 4386f57..979133f 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -39,6 +39,7 @@ GlobalProperty hw_compat_5_2[] = { { "ICH9-LPC", "smm-compat", "on"}, { "PIIX4_PM", "smm-compat", "on"}, + { "virtio-net-pci", "vectors", "3"}, }; const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2); diff --git a/hw/virtio/virtio-net-pci.c b/hw/virtio/virtio-net-pci.c index 292d13d..aa0b3ca 100644 --- a/hw/virtio/virtio-net-pci.c +++ b/hw/virtio/virtio-net-pci.c @@ -41,7 +41,8 @@ struct VirtIONetPCI { static Property virtio_net_properties[] = { DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true), - DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3), + DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, + DEV_NVECTORS_UNSPECIFIED), DEFINE_PROP_END_OF_LIST(), }; @@ -50,6 +51,13 @@ static void virtio_net_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) DeviceState *qdev = DEVICE(vpci_dev); VirtIONetPCI *dev = VIRTIO_NET_PCI(vpci_dev); DeviceState *vdev = DEVICE(&dev->vdev); + VirtIONet *net = VIRTIO_NET(vdev); + + if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { + vpci_dev->nvectors = 2 * MAX(net->nic_conf.peers.queues, 1) + + 1 /* Config interrupt */ + + 1 /* Control vq */; + } virtio_net_set_netclient_name(&dev->vdev, qdev->id, object_get_typename(OBJECT(qdev))); -- cgit v1.1