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ivshmem: Disentangle ivshmem_read()

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Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-24-git-send-email-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2016-03-15 19:34:38 +01:00
parent cd9953f720
commit ca0b7566cc
1 changed files with 84 additions and 83 deletions
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153
hw/misc/ivshmem.c
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@ -564,116 +564,117 @@ static void setup_interrupt(IVShmemState *s, int vector)
}
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
static void process_msg_shmem(IVShmemState *s, int fd)
{
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;
}
incoming_fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n",
incoming_posn, incoming_fd);
if (incoming_posn < -1 || incoming_posn > IVSHMEM_MAX_PEERS) {
error_report("server sent invalid message %" PRId64,
incoming_posn);
if (incoming_fd != -1) {
close(incoming_fd);
}
return;
}
if (incoming_posn >= s->nb_peers) {
resize_peers(s, incoming_posn + 1);
}
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;
void *ptr;
if (memory_region_is_mapped(&s->ivshmem)) {
error_report("shm already initialized");
close(incoming_fd);
close(fd);
return;
}
if (check_shm_size(s, incoming_fd, &err) == -1) {
if (check_shm_size(s, fd, &err) == -1) {
error_report_err(err);
close(incoming_fd);
close(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) {
ptr = mmap(0, s->ivshmem_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (ptr == MAP_FAILED) {
error_report("Failed to mmap shared memory %s", strerror(errno));
close(incoming_fd);
close(fd);
return;
}
memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
"ivshmem.bar2", s->ivshmem_size, map_ptr);
qemu_set_ram_fd(memory_region_get_ram_addr(&s->ivshmem),
incoming_fd);
"ivshmem.bar2", s->ivshmem_size, ptr);
qemu_set_ram_fd(memory_region_get_ram_addr(&s->ivshmem), 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;
}
static void process_msg_disconnect(IVShmemState *s, uint16_t posn)
{
IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
close_peer_eventfds(s, posn);
}
/* each peer has an associated array of eventfds, and we keep
* track of how many eventfds received so far */
/* get a new eventfd: */
static void process_msg_connect(IVShmemState *s, uint16_t posn, int fd)
{
Peer *peer = &s->peers[posn];
int vector;
/*
* The N-th connect message for this peer comes with the file
* descriptor for vector N-1. Count messages to find the vector.
*/
if (peer->nb_eventfds >= s->vectors) {
error_report("Too many eventfd received, device has %d vectors",
s->vectors);
close(incoming_fd);
close(fd);
return;
}
vector = peer->nb_eventfds++;
new_eventfd = peer->nb_eventfds++;
IVSHMEM_DPRINTF("eventfds[%d][%d] = %d\n", posn, vector, fd);
event_notifier_init_fd(&peer->eventfds[vector], fd);
fcntl_setfl(fd, O_NONBLOCK); /* msix/irqfd poll non block */
/* 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 (posn == s->vm_id) {
setup_interrupt(s, vector);
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
ivshmem_add_eventfd(s, incoming_posn, new_eventfd);
ivshmem_add_eventfd(s, posn, vector);
}
}
static void process_msg(IVShmemState *s, int64_t msg, int fd)
{
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
error_report("server sent invalid message %" PRId64, msg);
close(fd);
return;
}
if (msg == -1) {
process_msg_shmem(s, fd);
return;
}
if (msg >= s->nb_peers) {
resize_peers(s, msg + 1);
}
if (fd >= 0) {
process_msg_connect(s, msg, fd);
} else if (s->vm_id == -1) {
s->vm_id = msg;
} else {
process_msg_disconnect(s, msg);
}
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
int fd;
int64_t msg;
if (!fifo_update_and_get_i64(s, buf, size, &msg)) {
return;
}
fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
process_msg(s, msg, fd);
}
static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size)
{
IVShmemState *s = opaque;