qemu/hw/virtio-net.c

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