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qemu/hw/virtio-net.c
Michael S. Tsirkin ff3a8066e6 virtio-net: enable mrg buf header in tap on linux 
Modern linux supports arbitrary header size,
which makes it possible to pass mrg buf header
to tap directly without iovec mangling.
Use this capability when it is there.

This removes the need to deal with it in
vhost-net as we do now.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-10-29 18:25:23 +02:00

1103 lines
32 KiB
C
Raw Blame History

/*
* 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 "iov.h"
#include "virtio.h"
#include "net.h"
#include "net/checksum.h"
#include "net/tap.h"
#include "qemu-error.h"
#include "qemu-timer.h"
#include "virtio-net.h"
#include "vhost_net.h"
#define VIRTIO_NET_VM_VERSION 11
#define MAC_TABLE_ENTRIES 64
#define MAX_VLAN (1 << 12) /* Per 802.1Q definition */
typedef struct VirtIONet
{
VirtIODevice vdev;
uint8_t mac[ETH_ALEN];
uint16_t status;
VirtQueue *rx_vq;
VirtQueue *tx_vq;
VirtQueue *ctrl_vq;
NICState *nic;
QEMUTimer *tx_timer;
QEMUBH *tx_bh;
uint32_t tx_timeout;
int32_t tx_burst;
int tx_waiting;
uint32_t has_vnet_hdr;
size_t host_hdr_len;
size_t guest_hdr_len;
uint8_t has_ufo;
struct {
VirtQueueElement elem;
ssize_t len;
} async_tx;
int mergeable_rx_bufs;
uint8_t promisc;
uint8_t allmulti;
uint8_t alluni;
uint8_t nomulti;
uint8_t nouni;
uint8_t nobcast;
uint8_t vhost_started;
struct {
int in_use;
int first_multi;
uint8_t multi_overflow;
uint8_t uni_overflow;
uint8_t *macs;
} mac_table;
uint32_t *vlans;
DeviceState *qdev;
} 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_get_config(VirtIODevice *vdev, uint8_t *config)
{
VirtIONet *n = to_virtio_net(vdev);
struct virtio_net_config netcfg;
stw_p(&netcfg.status, n->status);
memcpy(netcfg.mac, n->mac, ETH_ALEN);
memcpy(config, &netcfg, sizeof(netcfg));
}
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
{
VirtIONet *n = to_virtio_net(vdev);
struct virtio_net_config netcfg;
memcpy(&netcfg, config, sizeof(netcfg));
if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
memcpy(n->mac, netcfg.mac, ETH_ALEN);
qemu_format_nic_info_str(&n->nic->nc, n->mac);
}
}
static bool virtio_net_started(VirtIONet *n, uint8_t status)
{
return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
(n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
}
static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
{
if (!n->nic->nc.peer) {
return;
}
if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
return;
}
if (!tap_get_vhost_net(n->nic->nc.peer)) {
return;
}
if (!!n->vhost_started == virtio_net_started(n, status) &&
!n->nic->nc.peer->link_down) {
return;
}
if (!n->vhost_started) {
int r;
if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer), &n->vdev)) {
return;
}
r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
if (r < 0) {
error_report("unable to start vhost net: %d: "
"falling back on userspace virtio", -r);
} else {
n->vhost_started = 1;
}
} else {
vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
n->vhost_started = 0;
}
}
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
{
VirtIONet *n = to_virtio_net(vdev);
virtio_net_vhost_status(n, status);
if (!n->tx_waiting) {
return;
}
if (virtio_net_started(n, status) && !n->vhost_started) {
if (n->tx_timer) {
qemu_mod_timer(n->tx_timer,
qemu_get_clock_ns(vm_clock) + n->tx_timeout);
} else {
qemu_bh_schedule(n->tx_bh);
}
} else {
if (n->tx_timer) {
qemu_del_timer(n->tx_timer);
} else {
qemu_bh_cancel(n->tx_bh);
}
}
}
static void virtio_net_set_link_status(NetClientState *nc)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
uint16_t old_status = n->status;
if (nc->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);
virtio_net_set_status(&n->vdev, n->vdev.status);
}
static void virtio_net_reset(VirtIODevice *vdev)
{
VirtIONet *n = to_virtio_net(vdev);
/* Reset back to compatibility mode */
n->promisc = 1;
n->allmulti = 0;
n->alluni = 0;
n->nomulti = 0;
n->nouni = 0;
n->nobcast = 0;
/* Flush any MAC and VLAN filter table state */
n->mac_table.in_use = 0;
n->mac_table.first_multi = 0;
n->mac_table.multi_overflow = 0;
n->mac_table.uni_overflow = 0;
memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
memset(n->vlans, 0, MAX_VLAN >> 3);
}
static void peer_test_vnet_hdr(VirtIONet *n)
{
if (!n->nic->nc.peer)
return;
if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP)
return;
n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
}
static int peer_has_vnet_hdr(VirtIONet *n)
{
return n->has_vnet_hdr;
}
static int peer_has_ufo(VirtIONet *n)
{
if (!peer_has_vnet_hdr(n))
return 0;
n->has_ufo = tap_has_ufo(n->nic->nc.peer);
return n->has_ufo;
}
static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs)
{
n->mergeable_rx_bufs = mergeable_rx_bufs;
n->guest_hdr_len = n->mergeable_rx_bufs ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
if (peer_has_vnet_hdr(n) &&
tap_has_vnet_hdr_len(n->nic->nc.peer, n->guest_hdr_len)) {
tap_set_vnet_hdr_len(n->nic->nc.peer, n->guest_hdr_len);
n->host_hdr_len = n->guest_hdr_len;
}
}
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
{
VirtIONet *n = to_virtio_net(vdev);
features |= (1 << VIRTIO_NET_F_MAC);
if (!peer_has_vnet_hdr(n)) {
features &= ~(0x1 << VIRTIO_NET_F_CSUM);
features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
}
if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
}
if (!n->nic->nc.peer ||
n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
return features;
}
if (!tap_get_vhost_net(n->nic->nc.peer)) {
return features;
}
return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
}
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
{
uint32_t features = 0;
/* Linux kernel 2.6.25. It understood MAC (as everyone must),
* but also these: */
features |= (1 << VIRTIO_NET_F_MAC);
features |= (1 << VIRTIO_NET_F_CSUM);
features |= (1 << VIRTIO_NET_F_HOST_TSO4);
features |= (1 << VIRTIO_NET_F_HOST_TSO6);
features |= (1 << VIRTIO_NET_F_HOST_ECN);
return features;
}
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
{
VirtIONet *n = to_virtio_net(vdev);
virtio_net_set_mrg_rx_bufs(n, !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF)));
if (n->has_vnet_hdr) {
tap_set_offload(n->nic->nc.peer,
(features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
(features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
(features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
(features >> VIRTIO_NET_F_GUEST_ECN) & 1,
(features >> VIRTIO_NET_F_GUEST_UFO) & 1);
}
if (!n->nic->nc.peer ||
n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
return;
}
if (!tap_get_vhost_net(n->nic->nc.peer)) {
return;
}
vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
}
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
VirtQueueElement *elem)
{
uint8_t on;
if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
error_report("virtio-net ctrl invalid rx mode command");
exit(1);
}
on = ldub_p(elem->out_sg[1].iov_base);
if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
n->promisc = on;
else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
n->allmulti = on;
else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
n->alluni = on;
else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
n->nomulti = on;
else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
n->nouni = on;
else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
n->nobcast = on;
else
return VIRTIO_NET_ERR;
return VIRTIO_NET_OK;
}
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
VirtQueueElement *elem)
{
struct virtio_net_ctrl_mac mac_data;
if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
elem->out_sg[1].iov_len < sizeof(mac_data) ||
elem->out_sg[2].iov_len < sizeof(mac_data))
return VIRTIO_NET_ERR;
n->mac_table.in_use = 0;
n->mac_table.first_multi = 0;
n->mac_table.uni_overflow = 0;
n->mac_table.multi_overflow = 0;
memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
mac_data.entries = ldl_p(elem->out_sg[1].iov_base);
if (sizeof(mac_data.entries) +
(mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
return VIRTIO_NET_ERR;
if (mac_data.entries <= MAC_TABLE_ENTRIES) {
memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
mac_data.entries * ETH_ALEN);
n->mac_table.in_use += mac_data.entries;
} else {
n->mac_table.uni_overflow = 1;
}
n->mac_table.first_multi = n->mac_table.in_use;
mac_data.entries = ldl_p(elem->out_sg[2].iov_base);
if (sizeof(mac_data.entries) +
(mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
return VIRTIO_NET_ERR;
if (mac_data.entries) {
if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
elem->out_sg[2].iov_base + sizeof(mac_data),
mac_data.entries * ETH_ALEN);
n->mac_table.in_use += mac_data.entries;
} else {
n->mac_table.multi_overflow = 1;
}
}
return VIRTIO_NET_OK;
}
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
VirtQueueElement *elem)
{
uint16_t vid;
if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
error_report("virtio-net ctrl invalid vlan command");
return VIRTIO_NET_ERR;
}
vid = lduw_p(elem->out_sg[1].iov_base);
if (vid >= MAX_VLAN)
return VIRTIO_NET_ERR;
if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
else
return VIRTIO_NET_ERR;
return VIRTIO_NET_OK;
}
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
struct virtio_net_ctrl_hdr ctrl;
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
VirtQueueElement elem;
while (virtqueue_pop(vq, &elem)) {
if ((elem.in_num < 1) || (elem.out_num < 1)) {
error_report("virtio-net ctrl missing headers");
exit(1);
}
if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
error_report("virtio-net ctrl header not in correct element");
exit(1);
}
ctrl.class = ldub_p(elem.out_sg[0].iov_base);
ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
virtqueue_push(vq, &elem, sizeof(status));
virtio_notify(vdev, vq);
}
}
/* RX */
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
qemu_flush_queued_packets(&n->nic->nc);
}
static int virtio_net_can_receive(NetClientState *nc)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
if (!n->vdev.vm_running) {
return 0;
}
if (!virtio_queue_ready(n->rx_vq) ||
!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
return 0;
return 1;
}
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
{
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);
/* To avoid a race condition where the guest has made some buffers
* available after the above check but before notification was
* enabled, check for available buffers again.
*/
if (virtio_queue_empty(n->rx_vq) ||
(n->mergeable_rx_bufs &&
!virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
return 0;
}
virtio_queue_set_notification(n->rx_vq, 0);
return 1;
}
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
* it never finds out that the packets don't have valid checksums. This
* causes dhclient to get upset. Fedora's carried a patch for ages to
* fix this with Xen but it hasn't appeared in an upstream release of
* dhclient yet.
*
* To avoid breaking existing guests, we catch udp packets and add
* checksums. This is terrible but it's better than hacking the guest
* kernels.
*
* N.B. if we introduce a zero-copy API, this operation is no longer free so
* we should provide a mechanism to disable it to avoid polluting the host
* cache.
*/
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
uint8_t *buf, size_t size)
{
if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
(size > 27 && size < 1500) && /* normal sized MTU */
(buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
(buf[23] == 17) && /* ip.protocol == UDP */
(buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
net_checksum_calculate(buf, size);
hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
}
}
static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
const void *buf, size_t size)
{
if (n->has_vnet_hdr) {
/* FIXME this cast is evil */
void *wbuf = (void *)buf;
work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
size - n->host_hdr_len);
iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
} else {
struct virtio_net_hdr hdr = {
.flags = 0,
.gso_type = VIRTIO_NET_HDR_GSO_NONE
};
iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
}
}
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
{
static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
static const uint8_t vlan[] = {0x81, 0x00};
uint8_t *ptr = (uint8_t *)buf;
int i;
if (n->promisc)
return 1;
ptr += n->host_hdr_len;
if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
return 0;
}
if (ptr[0] & 1) { // multicast
if (!memcmp(ptr, bcast, sizeof(bcast))) {
return !n->nobcast;
} else if (n->nomulti) {
return 0;
} else if (n->allmulti || n->mac_table.multi_overflow) {
return 1;
}
for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
return 1;
}
}
} else { // unicast
if (n->nouni) {
return 0;
} else if (n->alluni || n->mac_table.uni_overflow) {
return 1;
} else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
return 1;
}
for (i = 0; i < n->mac_table.first_multi; i++) {
if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
return 1;
}
}
}
return 0;
}
static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
struct virtio_net_hdr_mrg_rxbuf mhdr;
unsigned mhdr_cnt = 0;
size_t offset, i, guest_offset;
if (!virtio_net_can_receive(&n->nic->nc))
return -1;
/* hdr_len refers to the header we supply to the guest */
if (!virtio_net_has_buffers(n, size + n->guest_hdr_len - n->host_hdr_len))
return 0;
if (!receive_filter(n, buf, size))
return size;
offset = i = 0;
while (offset < size) {
VirtQueueElement elem;
int len, total;
const struct iovec *sg = elem.in_sg;
total = 0;
if (virtqueue_pop(n->rx_vq, &elem) == 0) {
if (i == 0)
return -1;
error_report("virtio-net unexpected empty queue: "
"i %zd mergeable %d offset %zd, size %zd, "
"guest hdr len %zd, host hdr len %zd guest features 0x%x",
i, n->mergeable_rx_bufs, offset, size,
n->guest_hdr_len, n->host_hdr_len, n->vdev.guest_features);
exit(1);
}
if (elem.in_num < 1) {
error_report("virtio-net receive queue contains no in buffers");
exit(1);
}
if (i == 0) {
assert(offset == 0);
if (n->mergeable_rx_bufs) {
mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
sg, elem.in_num,
offsetof(typeof(mhdr), num_buffers),
sizeof(mhdr.num_buffers));
}
receive_header(n, sg, elem.in_num, buf, size);
offset = n->host_hdr_len;
total += n->guest_hdr_len;
guest_offset = n->guest_hdr_len;
} else {
guest_offset = 0;
}
/* copy in packet. ugh */
len = iov_from_buf(sg, elem.in_num, guest_offset,
buf + offset, size - offset);
total += len;
offset += len;
/* If buffers can't be merged, at this point we
* must have consumed the complete packet.
* Otherwise, drop it. */
if (!n->mergeable_rx_bufs && offset < size) {
#if 0
error_report("virtio-net truncated non-mergeable packet: "
"i %zd mergeable %d offset %zd, size %zd, "
"guest hdr len %zd, host hdr len %zd",
i, n->mergeable_rx_bufs,
offset, size, n->guest_hdr_len, n->host_hdr_len);
#endif
return size;
}
/* signal other side */
virtqueue_fill(n->rx_vq, &elem, total, i++);
}
if (mhdr_cnt) {
stw_p(&mhdr.num_buffers, i);
iov_from_buf(mhdr_sg, mhdr_cnt,
0,
&mhdr.num_buffers, sizeof mhdr.num_buffers);
}
virtqueue_flush(n->rx_vq, i);
virtio_notify(&n->vdev, n->rx_vq);
return size;
}
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
virtqueue_push(n->tx_vq, &n->async_tx.elem, 0);
virtio_notify(&n->vdev, n->tx_vq);
n->async_tx.elem.out_num = n->async_tx.len = 0;
virtio_queue_set_notification(n->tx_vq, 1);
virtio_net_flush_tx(n, n->tx_vq);
}
/* TX */
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
{
VirtQueueElement elem;
int32_t num_packets = 0;
if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return num_packets;
}
assert(n->vdev.vm_running);
if (n->async_tx.elem.out_num) {
virtio_queue_set_notification(n->tx_vq, 0);
return num_packets;
}
while (virtqueue_pop(vq, &elem)) {
ssize_t ret, len;
unsigned int out_num = elem.out_num;
struct iovec *out_sg = &elem.out_sg[0];
struct iovec sg[VIRTQUEUE_MAX_SIZE];
if (out_num < 1) {
error_report("virtio-net header not in first element");
exit(1);
}
/*
* If host wants to see the guest header as is, we can
* pass it on unchanged. Otherwise, copy just the parts
* that host is interested in.
*/
assert(n->host_hdr_len <= n->guest_hdr_len);
if (n->host_hdr_len != n->guest_hdr_len) {
unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
out_sg, out_num,
0, n->host_hdr_len);
sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
out_sg, out_num,
n->guest_hdr_len, -1);
out_num = sg_num;
out_sg = sg;
}
len = n->guest_hdr_len;
ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
virtio_net_tx_complete);
if (ret == 0) {
virtio_queue_set_notification(n->tx_vq, 0);
n->async_tx.elem = elem;
n->async_tx.len = len;
return -EBUSY;
}
len += ret;
virtqueue_push(vq, &elem, 0);
virtio_notify(&n->vdev, vq);
if (++num_packets >= n->tx_burst) {
break;
}
}
return num_packets;
}
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
/* This happens when device was stopped but VCPU wasn't. */
if (!n->vdev.vm_running) {
n->tx_waiting = 1;
return;
}
if (n->tx_waiting) {
virtio_queue_set_notification(vq, 1);
qemu_del_timer(n->tx_timer);
n->tx_waiting = 0;
virtio_net_flush_tx(n, vq);
} else {
qemu_mod_timer(n->tx_timer,
qemu_get_clock_ns(vm_clock) + n->tx_timeout);
n->tx_waiting = 1;
virtio_queue_set_notification(vq, 0);
}
}
static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
if (unlikely(n->tx_waiting)) {
return;
}
n->tx_waiting = 1;
/* This happens when device was stopped but VCPU wasn't. */
if (!n->vdev.vm_running) {
return;
}
virtio_queue_set_notification(vq, 0);
qemu_bh_schedule(n->tx_bh);
}
static void virtio_net_tx_timer(void *opaque)
{
VirtIONet *n = opaque;
assert(n->vdev.vm_running);
n->tx_waiting = 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_tx_bh(void *opaque)
{
VirtIONet *n = opaque;
int32_t ret;
assert(n->vdev.vm_running);
n->tx_waiting = 0;
/* Just in case the driver is not ready on more */
if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
return;
ret = virtio_net_flush_tx(n, n->tx_vq);
if (ret == -EBUSY) {
return; /* Notification re-enable handled by tx_complete */
}
/* If we flush a full burst of packets, assume there are
* more coming and immediately reschedule */
if (ret >= n->tx_burst) {
qemu_bh_schedule(n->tx_bh);
n->tx_waiting = 1;
return;
}
/* If less than a full burst, re-enable notification and flush
* anything that may have come in while we weren't looking. If
* we find something, assume the guest is still active and reschedule */
virtio_queue_set_notification(n->tx_vq, 1);
if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
virtio_queue_set_notification(n->tx_vq, 0);
qemu_bh_schedule(n->tx_bh);
n->tx_waiting = 1;
}
}
static void virtio_net_save(QEMUFile *f, void *opaque)
{
VirtIONet *n = opaque;
/* At this point, backend must be stopped, otherwise
* it might keep writing to memory. */
assert(!n->vhost_started);
virtio_save(&n->vdev, f);
qemu_put_buffer(f, n->mac, ETH_ALEN);
qemu_put_be32(f, n->tx_waiting);
qemu_put_be32(f, n->mergeable_rx_bufs);
qemu_put_be16(f, n->status);
qemu_put_byte(f, n->promisc);
qemu_put_byte(f, n->allmulti);
qemu_put_be32(f, n->mac_table.in_use);
qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
qemu_put_be32(f, n->has_vnet_hdr);
qemu_put_byte(f, n->mac_table.multi_overflow);
qemu_put_byte(f, n->mac_table.uni_overflow);
qemu_put_byte(f, n->alluni);
qemu_put_byte(f, n->nomulti);
qemu_put_byte(f, n->nouni);
qemu_put_byte(f, n->nobcast);
qemu_put_byte(f, n->has_ufo);
}
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
{
VirtIONet *n = opaque;
int i;
int ret;
if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
return -EINVAL;
ret = virtio_load(&n->vdev, f);
if (ret) {
return ret;
}
qemu_get_buffer(f, n->mac, ETH_ALEN);
n->tx_waiting = qemu_get_be32(f);
virtio_net_set_mrg_rx_bufs(n, qemu_get_be32(f));
if (version_id >= 3)
n->status = qemu_get_be16(f);
if (version_id >= 4) {
if (version_id < 8) {
n->promisc = qemu_get_be32(f);
n->allmulti = qemu_get_be32(f);
} else {
n->promisc = qemu_get_byte(f);
n->allmulti = qemu_get_byte(f);
}
}
if (version_id >= 5) {
n->mac_table.in_use = qemu_get_be32(f);
/* MAC_TABLE_ENTRIES may be different from the saved image */
if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
qemu_get_buffer(f, n->mac_table.macs,
n->mac_table.in_use * ETH_ALEN);
} else if (n->mac_table.in_use) {
uint8_t *buf = g_malloc0(n->mac_table.in_use);
qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
g_free(buf);
n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
n->mac_table.in_use = 0;
}
}
if (version_id >= 6)
qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
if (version_id >= 7) {
if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
error_report("virtio-net: saved image requires vnet_hdr=on");
return -1;
}
if (n->has_vnet_hdr) {
tap_set_offload(n->nic->nc.peer,
(n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
(n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
(n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
(n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN) & 1,
(n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO) & 1);
}
}
if (version_id >= 9) {
n->mac_table.multi_overflow = qemu_get_byte(f);
n->mac_table.uni_overflow = qemu_get_byte(f);
}
if (version_id >= 10) {
n->alluni = qemu_get_byte(f);
n->nomulti = qemu_get_byte(f);
n->nouni = qemu_get_byte(f);
n->nobcast = qemu_get_byte(f);
}
if (version_id >= 11) {
if (qemu_get_byte(f) && !peer_has_ufo(n)) {
error_report("virtio-net: saved image requires TUN_F_UFO support");
return -1;
}
}
/* Find the first multicast entry in the saved MAC filter */
for (i = 0; i < n->mac_table.in_use; i++) {
if (n->mac_table.macs[i * ETH_ALEN] & 1) {
break;
}
}
n->mac_table.first_multi = i;
/* nc.link_down can't be migrated, so infer link_down according
* to link status bit in n->status */
n->nic->nc.link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
return 0;
}
static void virtio_net_cleanup(NetClientState *nc)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
n->nic = NULL;
}
static NetClientInfo net_virtio_info = {
.type = NET_CLIENT_OPTIONS_KIND_NIC,
.size = sizeof(NICState),
.can_receive = virtio_net_can_receive,
.receive = virtio_net_receive,
.cleanup = virtio_net_cleanup,
.link_status_changed = virtio_net_set_link_status,
};
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
virtio_net_conf *net)
{
VirtIONet *n;
n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
sizeof(struct virtio_net_config),
sizeof(VirtIONet));
n->vdev.get_config = virtio_net_get_config;
n->vdev.set_config = virtio_net_set_config;
n->vdev.get_features = virtio_net_get_features;
n->vdev.set_features = virtio_net_set_features;
n->vdev.bad_features = virtio_net_bad_features;
n->vdev.reset = virtio_net_reset;
n->vdev.set_status = virtio_net_set_status;
n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
error_report("virtio-net: "
"Unknown option tx=%s, valid options: \"timer\" \"bh\"",
net->tx);
error_report("Defaulting to \"bh\"");
}
if (net->tx && !strcmp(net->tx, "timer")) {
n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
n->tx_timeout = net->txtimer;
} else {
n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
}
n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
qemu_macaddr_default_if_unset(&conf->macaddr);
memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
n->status = VIRTIO_NET_S_LINK_UP;
n->nic = qemu_new_nic(&net_virtio_info, conf, object_get_typename(OBJECT(dev)), dev->id, n);
peer_test_vnet_hdr(n);
if (peer_has_vnet_hdr(n)) {
tap_using_vnet_hdr(n->nic->nc.peer, 1);
n->host_hdr_len = sizeof(struct virtio_net_hdr);
} else {
n->host_hdr_len = 0;
}
qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
n->tx_waiting = 0;
n->tx_burst = net->txburst;
virtio_net_set_mrg_rx_bufs(n, 0);
n->promisc = 1; /* for compatibility */
n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
n->vlans = g_malloc0(MAX_VLAN >> 3);
n->qdev = dev;
register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
virtio_net_save, virtio_net_load, n);
add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
return &n->vdev;
}
void virtio_net_exit(VirtIODevice *vdev)
{
VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
/* This will stop vhost backend if appropriate. */
virtio_net_set_status(vdev, 0);
qemu_purge_queued_packets(&n->nic->nc);
unregister_savevm(n->qdev, "virtio-net", n);
g_free(n->mac_table.macs);
g_free(n->vlans);
if (n->tx_timer) {
qemu_del_timer(n->tx_timer);
qemu_free_timer(n->tx_timer);
} else {
qemu_bh_delete(n->tx_bh);
}
qemu_del_net_client(&n->nic->nc);
virtio_cleanup(&n->vdev);
}
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