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Re: [Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read()
From: |
Marc-André Lureau |
Subject: |
Re: [Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read() |
Date: |
Wed, 9 Mar 2016 13:45:29 +0100 |
On Mon, Mar 7, 2016 at 8:25 PM, Markus Armbruster <address@hidden> wrote:
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
Reviewed-by: Marc-André Lureau <address@hidden>
> hw/misc/ivshmem.c | 172
> +++++++++++++++++++++++++++---------------------------
> 1 file changed, 87 insertions(+), 85 deletions(-)
>
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index 5d33be4..e568263 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -564,115 +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;
> + 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);
> - }
> - 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);
> - }
> + if (check_shm_size(s, fd, &err) == -1) {
> + error_report_err(err);
> + close(fd);
> 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);
> -
> + /* 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;
> }
> -
> - /* each peer has an associated array of eventfds, and we keep
> - * track of how many eventfds received so far */
> - /* get a new eventfd: */
> + memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
> + "ivshmem.bar2", s->ivshmem_size, ptr);
> + qemu_set_ram_fd(s->ivshmem.ram_addr, fd);
> + vmstate_register_ram(&s->ivshmem, DEVICE(s));
> + memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
> +}
> +
> +static void process_msg_disconnect(IVShmemState *s, uint16_t posn)
> +{
> + IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
> + close_peer_eventfds(s, 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(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;
> --
> 2.4.3
>
>
--
Marc-André Lureau
- [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name, (continued)
[Qemu-devel] [PATCH v2 16/42] ivshmem: Drop ivshmem_event() stub, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 23/42] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 24/42] ivshmem: Simplify rejection of invalid peer ID from server, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 36/42] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/07
- Re: [Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read(),
Marc-André Lureau <=
[Qemu-devel] [PATCH v2 40/42] ivshmem: Drop ivshmem property x-memdev, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 34/42] ivshmem: Simplify memory regions for BAR 2 (shared memory), Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 33/42] ivshmem: Implement shm=... with a memory backend, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 12/42] ivshmem: Rewrite specification document, Markus Armbruster, 2016/03/07