Support backend guest notifier masking in vhost-net: create eventfd at device init, when masked, make vhost use that as eventfd instead of sending an interrupt. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
259 lines
6.5 KiB
C
259 lines
6.5 KiB
C
/*
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* vhost-net support
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*
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* Copyright Red Hat, Inc. 2010
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*
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* Authors:
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* Michael S. Tsirkin <mst@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "net/net.h"
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#include "net/tap.h"
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#include "virtio-net.h"
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#include "vhost_net.h"
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#include "qemu/error-report.h"
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#include "config.h"
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#ifdef CONFIG_VHOST_NET
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#include <linux/vhost.h>
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#include <sys/socket.h>
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#include <linux/kvm.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <linux/virtio_ring.h>
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#include <netpacket/packet.h>
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#include <net/ethernet.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <stdio.h>
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#include "vhost.h"
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struct vhost_net {
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struct vhost_dev dev;
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struct vhost_virtqueue vqs[2];
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int backend;
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NetClientState *nc;
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};
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unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
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{
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/* Clear features not supported by host kernel. */
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if (!(net->dev.features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY))) {
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features &= ~(1 << VIRTIO_F_NOTIFY_ON_EMPTY);
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}
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if (!(net->dev.features & (1 << VIRTIO_RING_F_INDIRECT_DESC))) {
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features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
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}
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if (!(net->dev.features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
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features &= ~(1 << VIRTIO_RING_F_EVENT_IDX);
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}
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if (!(net->dev.features & (1 << VIRTIO_NET_F_MRG_RXBUF))) {
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features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
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}
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return features;
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}
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void vhost_net_ack_features(struct vhost_net *net, unsigned features)
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{
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net->dev.acked_features = net->dev.backend_features;
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if (features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) {
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net->dev.acked_features |= (1 << VIRTIO_F_NOTIFY_ON_EMPTY);
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}
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if (features & (1 << VIRTIO_RING_F_INDIRECT_DESC)) {
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net->dev.acked_features |= (1 << VIRTIO_RING_F_INDIRECT_DESC);
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}
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if (features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
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net->dev.acked_features |= (1 << VIRTIO_RING_F_EVENT_IDX);
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}
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if (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
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net->dev.acked_features |= (1 << VIRTIO_NET_F_MRG_RXBUF);
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}
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}
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static int vhost_net_get_fd(NetClientState *backend)
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{
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switch (backend->info->type) {
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case NET_CLIENT_OPTIONS_KIND_TAP:
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return tap_get_fd(backend);
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default:
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fprintf(stderr, "vhost-net requires tap backend\n");
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return -EBADFD;
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}
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}
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struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
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bool force)
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{
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int r;
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struct vhost_net *net = g_malloc(sizeof *net);
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if (!backend) {
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fprintf(stderr, "vhost-net requires backend to be setup\n");
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goto fail;
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}
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r = vhost_net_get_fd(backend);
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if (r < 0) {
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goto fail;
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}
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net->nc = backend;
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net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
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(1 << VHOST_NET_F_VIRTIO_NET_HDR);
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net->backend = r;
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net->dev.nvqs = 2;
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net->dev.vqs = net->vqs;
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r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", force);
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if (r < 0) {
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goto fail;
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}
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if (!tap_has_vnet_hdr_len(backend,
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sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
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net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
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}
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if (~net->dev.features & net->dev.backend_features) {
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fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n",
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(uint64_t)(~net->dev.features & net->dev.backend_features));
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vhost_dev_cleanup(&net->dev);
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goto fail;
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}
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/* Set sane init value. Override when guest acks. */
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vhost_net_ack_features(net, 0);
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return net;
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fail:
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g_free(net);
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return NULL;
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}
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bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
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{
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return vhost_dev_query(&net->dev, dev);
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}
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int vhost_net_start(struct vhost_net *net,
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VirtIODevice *dev)
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{
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struct vhost_vring_file file = { };
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int r;
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r = vhost_dev_enable_notifiers(&net->dev, dev);
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if (r < 0) {
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goto fail_notifiers;
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}
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r = vhost_dev_start(&net->dev, dev);
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if (r < 0) {
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goto fail_start;
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}
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net->nc->info->poll(net->nc, false);
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qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
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file.fd = net->backend;
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for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
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r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
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if (r < 0) {
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r = -errno;
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goto fail;
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}
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}
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return 0;
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fail:
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file.fd = -1;
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while (file.index-- > 0) {
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int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
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assert(r >= 0);
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}
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net->nc->info->poll(net->nc, true);
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vhost_dev_stop(&net->dev, dev);
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fail_start:
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vhost_dev_disable_notifiers(&net->dev, dev);
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fail_notifiers:
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return r;
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}
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void vhost_net_stop(struct vhost_net *net,
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VirtIODevice *dev)
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{
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struct vhost_vring_file file = { .fd = -1 };
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for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
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int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
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assert(r >= 0);
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}
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net->nc->info->poll(net->nc, true);
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vhost_dev_stop(&net->dev, dev);
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vhost_dev_disable_notifiers(&net->dev, dev);
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}
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void vhost_net_cleanup(struct vhost_net *net)
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{
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vhost_dev_cleanup(&net->dev);
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g_free(net);
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}
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bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
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{
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return vhost_virtqueue_pending(&net->dev, idx);
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}
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void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
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int idx, bool mask)
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{
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vhost_virtqueue_mask(&net->dev, dev, idx, mask);
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}
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#else
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struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
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bool force)
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{
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error_report("vhost-net support is not compiled in");
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return NULL;
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}
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bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
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{
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return false;
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}
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int vhost_net_start(struct vhost_net *net,
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VirtIODevice *dev)
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{
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return -ENOSYS;
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}
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void vhost_net_stop(struct vhost_net *net,
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VirtIODevice *dev)
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{
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}
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void vhost_net_cleanup(struct vhost_net *net)
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{
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}
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unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
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{
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return features;
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}
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void vhost_net_ack_features(struct vhost_net *net, unsigned features)
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{
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}
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bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
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{
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return -ENOSYS;
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}
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void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
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int idx, bool mask)
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{
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}
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#endif
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