root / hw / virtio-net.c @ 291c6ff9
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/*
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* Virtio Network Device
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*
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* Copyright IBM, Corp. 2007
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.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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*/
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#include "virtio.h" |
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#include "net.h" |
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#include "qemu-timer.h" |
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#include "virtio-net.h" |
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typedef struct VirtIONet |
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{ |
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VirtIODevice vdev; |
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uint8_t mac[6];
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uint16_t status; |
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VirtQueue *rx_vq; |
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VirtQueue *tx_vq; |
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VLANClientState *vc; |
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QEMUTimer *tx_timer; |
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int tx_timer_active;
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int mergeable_rx_bufs;
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} VirtIONet; |
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/* TODO
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* - we could suppress RX interrupt if we were so inclined.
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*/
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static VirtIONet *to_virtio_net(VirtIODevice *vdev)
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{ |
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return (VirtIONet *)vdev;
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} |
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static void virtio_net_update_config(VirtIODevice *vdev, uint8_t *config) |
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{ |
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VirtIONet *n = to_virtio_net(vdev); |
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struct virtio_net_config netcfg;
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netcfg.status = n->status; |
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memcpy(netcfg.mac, n->mac, 6);
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memcpy(config, &netcfg, sizeof(netcfg));
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} |
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static void virtio_net_set_link_status(VLANClientState *vc) |
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{ |
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VirtIONet *n = vc->opaque; |
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uint16_t old_status = n->status; |
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if (vc->link_down)
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n->status &= ~VIRTIO_NET_S_LINK_UP; |
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else
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n->status |= VIRTIO_NET_S_LINK_UP; |
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if (n->status != old_status)
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virtio_notify_config(&n->vdev); |
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} |
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static uint32_t virtio_net_get_features(VirtIODevice *vdev)
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{ |
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uint32_t features = (1 << VIRTIO_NET_F_MAC) | (1 << VIRTIO_NET_F_STATUS); |
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return features;
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} |
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static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features) |
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{ |
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VirtIONet *n = to_virtio_net(vdev); |
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n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
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} |
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/* RX */
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static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq) |
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{ |
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} |
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static int do_virtio_net_can_receive(VirtIONet *n, int bufsize) |
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{ |
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if (!virtio_queue_ready(n->rx_vq) ||
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!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) |
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return 0; |
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if (virtio_queue_empty(n->rx_vq) ||
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(n->mergeable_rx_bufs && |
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!virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
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virtio_queue_set_notification(n->rx_vq, 1);
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return 0; |
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} |
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virtio_queue_set_notification(n->rx_vq, 0);
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return 1; |
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} |
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static int virtio_net_can_receive(void *opaque) |
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{ |
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VirtIONet *n = opaque; |
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return do_virtio_net_can_receive(n, VIRTIO_NET_MAX_BUFSIZE);
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} |
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static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count) |
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{ |
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int offset, i;
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offset = i = 0;
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while (offset < count && i < iovcnt) {
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int len = MIN(iov[i].iov_len, count - offset);
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memcpy(iov[i].iov_base, buf + offset, len); |
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offset += len; |
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i++; |
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} |
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return offset;
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} |
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static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt, |
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const void *buf, size_t size, size_t hdr_len) |
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{ |
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struct virtio_net_hdr *hdr = iov[0].iov_base; |
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int offset = 0; |
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hdr->flags = 0;
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hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; |
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/* We only ever receive a struct virtio_net_hdr from the tapfd,
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* but we may be passing along a larger header to the guest.
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*/
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iov[0].iov_base += hdr_len;
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iov[0].iov_len -= hdr_len;
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return offset;
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} |
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static void virtio_net_receive(void *opaque, const uint8_t *buf, int size) |
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{ |
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VirtIONet *n = opaque; |
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struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL; |
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size_t hdr_len, offset, i; |
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if (!do_virtio_net_can_receive(n, size))
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return;
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/* hdr_len refers to the header we supply to the guest */
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hdr_len = n->mergeable_rx_bufs ? |
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sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); |
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offset = i = 0;
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while (offset < size) {
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VirtQueueElement elem; |
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int len, total;
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struct iovec sg[VIRTQUEUE_MAX_SIZE];
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len = total = 0;
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if ((i != 0 && !n->mergeable_rx_bufs) || |
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virtqueue_pop(n->rx_vq, &elem) == 0) {
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if (i == 0) |
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return;
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fprintf(stderr, "virtio-net truncating packet\n");
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exit(1);
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} |
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if (elem.in_num < 1) { |
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fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
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exit(1);
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} |
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if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) { |
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fprintf(stderr, "virtio-net header not in first element\n");
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exit(1);
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} |
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memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num); |
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if (i == 0) { |
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if (n->mergeable_rx_bufs)
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mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base; |
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offset += receive_header(n, sg, elem.in_num, |
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buf + offset, size - offset, hdr_len); |
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total += hdr_len; |
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} |
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/* copy in packet. ugh */
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len = iov_fill(sg, elem.in_num, |
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buf + offset, size - offset); |
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total += len; |
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/* signal other side */
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virtqueue_fill(n->rx_vq, &elem, total, i++); |
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offset += len; |
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} |
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if (mhdr)
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mhdr->num_buffers = i; |
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virtqueue_flush(n->rx_vq, i); |
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virtio_notify(&n->vdev, n->rx_vq); |
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} |
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/* TX */
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static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq) |
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{ |
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VirtQueueElement elem; |
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int has_vnet_hdr = 0; |
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if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
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return;
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while (virtqueue_pop(vq, &elem)) {
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ssize_t len = 0;
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unsigned int out_num = elem.out_num; |
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struct iovec *out_sg = &elem.out_sg[0]; |
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unsigned hdr_len;
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/* hdr_len refers to the header received from the guest */
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hdr_len = n->mergeable_rx_bufs ? |
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sizeof(struct virtio_net_hdr_mrg_rxbuf) : |
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sizeof(struct virtio_net_hdr); |
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if (out_num < 1 || out_sg->iov_len != hdr_len) { |
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fprintf(stderr, "virtio-net header not in first element\n");
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exit(1);
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} |
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/* ignore the header if GSO is not supported */
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if (!has_vnet_hdr) {
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out_num--; |
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out_sg++; |
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len += hdr_len; |
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} else if (n->mergeable_rx_bufs) { |
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/* tapfd expects a struct virtio_net_hdr */
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hdr_len -= sizeof(struct virtio_net_hdr); |
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out_sg->iov_len -= hdr_len; |
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len += hdr_len; |
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} |
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len += qemu_sendv_packet(n->vc, out_sg, out_num); |
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virtqueue_push(vq, &elem, len); |
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virtio_notify(&n->vdev, vq); |
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} |
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} |
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static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq) |
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{ |
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VirtIONet *n = to_virtio_net(vdev); |
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if (n->tx_timer_active) {
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virtio_queue_set_notification(vq, 1);
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qemu_del_timer(n->tx_timer); |
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n->tx_timer_active = 0;
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virtio_net_flush_tx(n, vq); |
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} else {
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qemu_mod_timer(n->tx_timer, |
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qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL); |
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n->tx_timer_active = 1;
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virtio_queue_set_notification(vq, 0);
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} |
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} |
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static void virtio_net_tx_timer(void *opaque) |
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{ |
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VirtIONet *n = opaque; |
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n->tx_timer_active = 0;
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/* Just in case the driver is not ready on more */
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if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
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return;
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virtio_queue_set_notification(n->tx_vq, 1);
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virtio_net_flush_tx(n, n->tx_vq); |
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} |
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static void virtio_net_save(QEMUFile *f, void *opaque) |
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{ |
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VirtIONet *n = opaque; |
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virtio_save(&n->vdev, f); |
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qemu_put_buffer(f, n->mac, 6);
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qemu_put_be32(f, n->tx_timer_active); |
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qemu_put_be32(f, n->mergeable_rx_bufs); |
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} |
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static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) |
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{ |
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VirtIONet *n = opaque; |
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if (version_id != 2) |
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return -EINVAL;
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virtio_load(&n->vdev, f); |
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qemu_get_buffer(f, n->mac, 6);
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n->tx_timer_active = qemu_get_be32(f); |
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n->mergeable_rx_bufs = qemu_get_be32(f); |
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if (n->tx_timer_active) {
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qemu_mod_timer(n->tx_timer, |
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qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL); |
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} |
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return 0; |
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} |
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void virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn) |
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{ |
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VirtIONet *n; |
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static int virtio_net_id; |
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n = (VirtIONet *)virtio_init_pci(bus, "virtio-net", 6900, 0x1000, |
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0, VIRTIO_ID_NET,
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0x02, 0x00, 0x00, |
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sizeof(struct virtio_net_config), |
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sizeof(VirtIONet));
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if (!n)
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return;
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n->vdev.get_config = virtio_net_update_config; |
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n->vdev.get_features = virtio_net_get_features; |
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n->vdev.set_features = virtio_net_set_features; |
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n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
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n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
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memcpy(n->mac, nd->macaddr, 6);
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n->status = VIRTIO_NET_S_LINK_UP; |
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n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name, |
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virtio_net_receive, virtio_net_can_receive, n); |
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n->vc->link_status_changed = virtio_net_set_link_status; |
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qemu_format_nic_info_str(n->vc, n->mac); |
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n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n); |
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n->tx_timer_active = 0;
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n->mergeable_rx_bufs = 0;
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register_savevm("virtio-net", virtio_net_id++, 2, |
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virtio_net_save, virtio_net_load, n); |
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} |