diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 703b3bff4cea4002be7312702dcebbb444eb0a11..d8d363e9ac322a3b960c5736bd44ba4f5d5e04a5 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -564,114 +564,115 @@ 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; + void *ptr; - if (!fifo_update_and_get_i64(s, buf, size, &incoming_posn)) { + if (memory_region_is_mapped(&s->ivshmem)) { + error_report("shm already initialized"); + close(fd); 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); - } + if (check_shm_size(s, fd, &err) == -1) { + error_report_err(err); + close(fd); return; } - if (incoming_posn >= s->nb_peers) { - resize_peers(s, incoming_posn + 1); + /* mmap the region and map into the BAR2 */ + 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(fd); + return; } + memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), + "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)); + memory_region_add_subregion(&s->bar, 0, &s->ivshmem); +} - peer = &s->peers[incoming_posn]; +static void process_msg_disconnect(IVShmemState *s, uint16_t posn) +{ + IVSHMEM_DPRINTF("posn %d has gone away\n", posn); + close_peer_eventfds(s, 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); - } +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(fd); return; } + vector = peer->nb_eventfds++; - /* 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; - } + 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 */ - /* 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(memory_region_get_ram_addr(&s->ivshmem), - incoming_fd); - vmstate_register_ram(&s->ivshmem, DEVICE(s)); + if (posn == s->vm_id) { + setup_interrupt(s, vector); + } - IVSHMEM_DPRINTF("guest h/w addr = %p, size = %" PRIu64 "\n", - map_ptr, s->ivshmem_size); + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + ivshmem_add_eventfd(s, posn, vector); + } +} - memory_region_add_subregion(&s->bar, 0, &s->ivshmem); +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; } - /* 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); + if (msg == -1) { + process_msg_shmem(s, 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 (msg >= s->nb_peers) { + resize_peers(s, msg + 1); + } - if (incoming_posn == s->vm_id) { - setup_interrupt(s, new_eventfd); + 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); } +} - if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { - ivshmem_add_eventfd(s, incoming_posn, new_eventfd); +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)