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virtio-net.c
1251 lines (1043 loc) · 37.8 KB
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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 "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 */
/*
* Unfortunately some guest virtio drivers are a little racy with respect to
* when they notify us and when they unmask their respective interrupts.
* Currently we have to work around this in QEMU. While OSes normally work
* around pathological devices, virtual devices here will have to work around
* virtual hardware. To put this more concretely, a Linux guest will notify the
* host to do processing work before it unmasks interrupts. Therefore, by the
* time that we get to virtio_notify interrupts on the available ring won't be
* unmasked so we won't inject the interrupt, but the guest will instead wait
* indefinitely for one. This leads to us losing data.
*
* We need to note whether or not we injected an interrupt during a
* virtio_notify. If we did not and either of the following conditions about the
* ring buffers are true:
*
* o The last available index processed equals the used index
* o The last available index processed does not equal the current
* available index
*
* If this is the case, then we set up a small timer that runs for 500 ticks,
* each tick is 10ms long. If we reach 500 ticks, then we just ignore it. This
* is actually a valid position because the guest could have transmitted a small
* amount of packets, but not enough to actually cause it to need injection. If
* we get notified, aka hit virtio_net_handle_tx_timer, then we stop the timer,
* because we're about to do processing that may inject an interrupt. Finally,
* if on a tick we check two different conditions. The first is to see if the
* last processed available ring index is not equal to the current available
* ring index. If that is true, then we effectively call virtqueue_flush as
* virtio_net_tx_timer would. Finally we check if the last available ring index
* is equal to the used ring index and interrupts are not masked. If this is the
* case, then we simply inject the interrupt and continue.
*
* This is summarized by the following rough state transition diagram:
*
* Otherwise +---+
* virtqueue_ --+ increment +---* |
* flush() | tick count \|/ | + avail ring
* finishes | +-------------+ | | index >
* without +---*-------------------->| |--+ | last avail
* injecting| | Timer | | index pro-
* an intr. | +-----*-------------| Active | | cessed
* | | | | |-----*-----------+
* | | | +-------------+ |
* | | +- 500 ticks | | |
* | | elapse | *--+ Avail ring |
* | \|/ | | unmasked |
* +-------------+ | | |
* | |<--*-----------+ | +--------+ |
* | Timer | | | | | |
* | Inactive | +- virtio_net_ +---->| Inject | |
* | | handle_tx_ | MSI/x | |
* +-------------+ timer() runs | | |
* ^ ^ +--------+ |
* | | +- always | |
* | | | | |
* | +-----------------------*------------+ |
* | |
* | +- always +------------------+ |
* | | | | |
* +---------------*---------------| Flush Virtqueues |<-----+
* | |
* +------------------+
*/
#define REINJECT_TICK_RATE (10000000) /* 10ms in ns */
#define REINJECT_DEADMAN 500 /* 5s in ticks */
typedef enum rein_act {
REIN_INJECT,
REIN_DEADMAN,
REIN_RUN
} rein_act_t;
#define REIN_RING_MAX 64
typedef struct rein_event {
rein_act_t re_act;
hrtime_t re_time;
uint64_t re_other;
struct timeval re_tval;
} rein_event_t;
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;
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;
QEMUTimer *rein_timer;
uint32_t rein_timer_ticks;
uint8_t rein_timer_act;
uint32_t rein_ring_idx;
rein_event_t rein_ring[REIN_RING_MAX];
uint64_t rein_n_dead;
uint64_t rein_n_inject;
uint64_t rein_n_rerun;
} VirtIONet;
static void virtio_net_handle_tx_timer(VirtIODevice *, VirtQueue *);
static void virtio_net_rein_event(VirtIONet *n, rein_act_t act, uint64_t other)
{
int index = n->rein_ring_idx;
n->rein_ring_idx = (n->rein_ring_idx + 1) % REIN_RING_MAX;
rein_event_t *rep = n->rein_ring + index;
rep->re_time = gethrtime();
rep->re_act = act;
rep->re_other = other;
(void) gettimeofday(&rep->re_tval, NULL);
}
static void virtio_net_rein_disable(VirtIONet *n)
{
qemu_del_timer(n->rein_timer);
n->rein_timer_act = 0;
}
static void virtio_net_rein_enable(VirtIONet *n)
{
n->rein_timer_ticks = 0;
qemu_mod_timer(n->rein_timer,
qemu_get_clock(vm_clock) + REINJECT_TICK_RATE);
n->rein_timer_act = 1;
}
static void virtio_net_rein_tick(void *opaque)
{
int ret;
VirtIONet *n = opaque;
assert(n->rein_timer_act);
n->rein_timer_ticks++;
/* Give up, this may be completely reasonable */
if (n->rein_timer_ticks > REINJECT_DEADMAN) {
virtio_net_rein_event(n, REIN_DEADMAN, n->rein_timer_ticks);
virtio_net_rein_disable(n);
n->rein_n_dead++;
return;
}
ret = virtqueue_stalled(n->tx_vq);
if (ret == 1) {
virtio_net_rein_event(n, REIN_INJECT, n->rein_timer_ticks);
virtio_net_rein_disable(n);
n->rein_n_inject++;
return;
} else if (ret == 2) {
virtio_net_rein_event(n, REIN_RUN, n->rein_timer_ticks);
virtio_net_rein_disable(n);
virtio_net_handle_tx_timer(&n->vdev, n->tx_vq);
n->rein_n_rerun++;
return;
}
assert(ret == 0);
qemu_mod_timer(n->rein_timer,
qemu_get_clock(vm_clock) + REINJECT_TICK_RATE);
}
/* 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_TYPE_TAP) {
return;
}
if (!tap_get_vhost_net(n->nic->nc.peer)) {
return;
}
if (!!n->vhost_started == virtio_net_started(n, status)) {
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(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(VLANClientState *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 int peer_has_vnet_hdr(VirtIONet *n)
{
if (!n->nic->nc.peer)
return 0;
if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
return 0;
n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
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 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)) {
tap_using_vnet_hdr(n->nic->nc.peer, 1);
} else {
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_TYPE_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);
n->mergeable_rx_bufs = !!(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_TYPE_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);
/* We now have RX buffers, signal to the IO thread to break out of the
* select to re-poll the tap file descriptor */
qemu_notify_event();
}
static int virtio_net_can_receive(VLANClientState *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,
const 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 */
/* FIXME this cast is evil */
net_checksum_calculate((uint8_t *)buf, size);
hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
}
}
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 = (struct virtio_net_hdr *)iov[0].iov_base;
int offset = 0;
hdr->flags = 0;
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
if (n->has_vnet_hdr) {
memcpy(hdr, buf, sizeof(*hdr));
offset = sizeof(*hdr);
work_around_broken_dhclient(hdr, buf + offset, size - offset);
}
/* 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 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;
if (n->has_vnet_hdr) {
ptr += sizeof(struct virtio_net_hdr);
}
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(VLANClientState *nc, const uint8_t *buf, size_t size)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
size_t guest_hdr_len, offset, i, host_hdr_len;
if (!virtio_net_can_receive(&n->nic->nc))
return -1;
/* hdr_len refers to the header we supply to the guest */
guest_hdr_len = n->mergeable_rx_bufs ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
return 0;
if (!receive_filter(n, buf, size))
return size;
offset = i = 0;
while (offset < size) {
VirtQueueElement elem;
int len, total;
struct iovec sg[VIRTQUEUE_MAX_SIZE];
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,
guest_hdr_len, 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 (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != guest_hdr_len) {
error_report("virtio-net header not in first element");
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, guest_hdr_len);
total += guest_hdr_len;
}
/* copy in packet. ugh */
len = iov_from_buf(sg, elem.in_num,
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, guest_hdr_len, host_hdr_len);
#endif
return size;
}
/* signal other side */
virtqueue_fill(n->rx_vq, &elem, total, i++);
}
if (mhdr) {
stw_p(&mhdr->num_buffers, i);
}
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(VLANClientState *nc, ssize_t len)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
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;
int32_t inject = 1;
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 = 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) {
error_report("virtio-net header not in first element");
exit(1);
}
/* ignore the header if GSO is not supported */
if (!n->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;
}
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, len);
inject = virtio_notify(&n->vdev, vq);
if (++num_packets >= n->tx_burst) {
break;
}
}
if (inject == 0 && virtqueue_handled(vq))
virtio_net_rein_enable(n);
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;
}
/*
* Kill the broken guest timer. The reason we are here is because the guest
* has kicked us to send packets therefore we don't need to go back and
* consider injecting it with interrupts because we will do that again
* naturally. We also don't reset
*/
if (n->rein_timer_act)
virtio_net_rein_disable(n);
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(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;