static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp)
{
int64_t msg;
int n, ret;
n = 0;
do {
ret = qemu_chr_fe_read_all(s->server_chr, (uint8_t *)&msg + n,
sizeof(msg) - n);
if (ret < 0 && ret != -EINTR) {
error_setg_errno(errp, -ret, "read from server failed");
return INT64_MIN;
}
n += ret;
} while (n < sizeof(msg));
*pfd = qemu_chr_fe_get_msgfd(s->server_chr);
return msg;
}
static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size)
{
IVShmemState *s = opaque;
int tmp;
int64_t version;
if (!fifo_update_and_get_i64(s, buf, size, &version)) {
return;
}
tmp = qemu_chr_fe_get_msgfd(s->server_chr);
if (tmp != -1 || version != IVSHMEM_PROTOCOL_VERSION) {
fprintf(stderr, "incompatible version, you are connecting to a ivshmem-"
"server using a different protocol please check your setup\n");
qemu_chr_delete(s->server_chr);
s->server_chr = NULL;
return;
}
IVSHMEM_DPRINTF("version check ok, switch to real chardev handler\n");
qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
ivshmem_event, s);
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
Error *err = NULL;
int fd;
int64_t msg;
assert(size >= 0 && s->msg_buffered_bytes + size <= sizeof(s->msg_buf));
memcpy((unsigned char *)&s->msg_buf + s->msg_buffered_bytes, buf, size);
s->msg_buffered_bytes += size;
if (s->msg_buffered_bytes < sizeof(s->msg_buf)) {
return;
}
msg = le64_to_cpu(s->msg_buf);
s->msg_buffered_bytes = 0;
fd = qemu_chr_fe_get_msgfd(&s->server_chr);
process_msg(s, msg, fd, &err);
if (err) {
error_report_err(err);
}
}
static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
{
IVShmemState *s = opaque;
int incoming_fd, tmp_fd;
int guest_max_eventfd;
long incoming_posn;
memcpy(&incoming_posn, buf, sizeof(long));
/* pick off s->server_chr->msgfd and store it, posn should accompany msg */
tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd);
/* make sure we have enough space for this guest */
if (incoming_posn >= s->nb_peers) {
increase_dynamic_storage(s, incoming_posn);
}
if (tmp_fd == -1) {
/* if posn is positive and unseen before then this is our posn*/
if ((incoming_posn >= 0) &&
(s->peers[incoming_posn].eventfds == NULL)) {
/* receive our posn */
s->vm_id = incoming_posn;
return;
} else {
/* otherwise an fd == -1 means an existing guest has gone away */
IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn);
close_guest_eventfds(s, incoming_posn);
return;
}
}
/* because of the implementation of get_msgfd, we need a dup */
incoming_fd = dup(tmp_fd);
if (incoming_fd == -1) {
fprintf(stderr, "could not allocate file descriptor %s\n",
strerror(errno));
return;
}
/* if the position is -1, then it's shared memory region fd */
if (incoming_posn == -1) {
void * map_ptr;
s->max_peer = 0;
if (check_shm_size(s, incoming_fd) == -1) {
exit(-1);
}
/* mmap the region and map into the BAR2 */
map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
incoming_fd, 0);
memory_region_init_ram_ptr(&s->ivshmem,
"ivshmem.bar2", s->ivshmem_size, map_ptr);
vmstate_register_ram(&s->ivshmem, &s->dev.qdev);
IVSHMEM_DPRINTF("guest h/w addr = %" PRIu64 ", size = %" PRIu64 "\n",
s->ivshmem_offset, s->ivshmem_size);
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
/* only store the fd if it is successfully mapped */
s->shm_fd = incoming_fd;
return;
}
/* each guest has an array of eventfds, and we keep track of how many
* guests for each VM */
guest_max_eventfd = s->peers[incoming_posn].nb_eventfds;
if (guest_max_eventfd == 0) {
/* one eventfd per MSI vector */
s->peers[incoming_posn].eventfds = g_new(EventNotifier, s->vectors);
}
/* this is an eventfd for a particular guest VM */
IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
guest_max_eventfd, incoming_fd);
event_notifier_init_fd(&s->peers[incoming_posn].eventfds[guest_max_eventfd],
incoming_fd);
/* increment count for particular guest */
s->peers[incoming_posn].nb_eventfds++;
/* keep track of the maximum VM ID */
if (incoming_posn > s->max_peer) {
s->max_peer = incoming_posn;
}
if (incoming_posn == s->vm_id) {
s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s,
&s->peers[s->vm_id].eventfds[guest_max_eventfd],
guest_max_eventfd);
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
ivshmem_add_eventfd(s, incoming_posn, guest_max_eventfd);
}
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
int incoming_fd;
int new_eventfd;
int64_t incoming_posn;
Error *err = NULL;
Peer *peer;
if (!fifo_update_and_get_i64(s, buf, size, &incoming_posn)) {
return;
}
if (incoming_posn < -1) {
IVSHMEM_DPRINTF("invalid incoming_posn %" PRId64 "\n", incoming_posn);
return;
}
/* pick off s->server_chr->msgfd and store it, posn should accompany msg */
incoming_fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n",
incoming_posn, incoming_fd);
/* make sure we have enough space for this peer */
if (incoming_posn >= s->nb_peers) {
if (resize_peers(s, incoming_posn + 1) < 0) {
error_report("failed to resize peers array");
if (incoming_fd != -1) {
close(incoming_fd);
}
return;
}
}
peer = &s->peers[incoming_posn];
if (incoming_fd == -1) {
/* if posn is positive and unseen before then this is our posn*/
if (incoming_posn >= 0 && s->vm_id == -1) {
/* receive our posn */
s->vm_id = incoming_posn;
} else {
/* otherwise an fd == -1 means an existing peer has gone away */
IVSHMEM_DPRINTF("posn %" PRId64 " has gone away\n", incoming_posn);
close_peer_eventfds(s, incoming_posn);
}
return;
}
/* if the position is -1, then it's shared memory region fd */
if (incoming_posn == -1) {
void * map_ptr;
if (memory_region_is_mapped(&s->ivshmem)) {
error_report("shm already initialized");
close(incoming_fd);
return;
}
if (check_shm_size(s, incoming_fd, &err) == -1) {
error_report_err(err);
close(incoming_fd);
return;
}
/* mmap the region and map into the BAR2 */
map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
incoming_fd, 0);
if (map_ptr == MAP_FAILED) {
error_report("Failed to mmap shared memory %s", strerror(errno));
close(incoming_fd);
return;
}
memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
"ivshmem.bar2", s->ivshmem_size, map_ptr);
qemu_set_ram_fd(s->ivshmem.ram_addr, incoming_fd);
vmstate_register_ram(&s->ivshmem, DEVICE(s));
IVSHMEM_DPRINTF("guest h/w addr = %p, size = %" PRIu64 "\n",
map_ptr, s->ivshmem_size);
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
return;
}
/* each peer has an associated array of eventfds, and we keep
* track of how many eventfds received so far */
/* get a new eventfd: */
if (peer->nb_eventfds >= s->vectors) {
error_report("Too many eventfd received, device has %d vectors",
s->vectors);
close(incoming_fd);
return;
}
new_eventfd = peer->nb_eventfds++;
/* this is an eventfd for a particular peer VM */
IVSHMEM_DPRINTF("eventfds[%" PRId64 "][%d] = %d\n", incoming_posn,
new_eventfd, incoming_fd);
event_notifier_init_fd(&peer->eventfds[new_eventfd], incoming_fd);
fcntl_setfl(incoming_fd, O_NONBLOCK); /* msix/irqfd poll non block */
if (incoming_posn == s->vm_id) {
setup_interrupt(s, new_eventfd);
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
ivshmem_add_eventfd(s, incoming_posn, new_eventfd);
}
}