diff options
| -rw-r--r-- | hw/block/vhost-user-blk.c | 41 | ||||
| -rw-r--r-- | hw/virtio/vhost-user-gpio.c | 11 | ||||
| -rw-r--r-- | hw/virtio/vhost-user.c | 71 | ||||
| -rw-r--r-- | include/hw/virtio/vhost-user.h | 18 |
4 files changed, 104 insertions, 37 deletions
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 1177064631..aff4d2b8cb 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -369,17 +369,10 @@ static void vhost_user_blk_disconnect(DeviceState *dev) vhost_user_blk_stop(vdev); vhost_dev_cleanup(&s->dev); -} -static void vhost_user_blk_chr_closed_bh(void *opaque) -{ - DeviceState *dev = opaque; - VirtIODevice *vdev = VIRTIO_DEVICE(dev); - VHostUserBlk *s = VHOST_USER_BLK(vdev); - - vhost_user_blk_disconnect(dev); + /* Re-instate the event handler for new connections */ qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, - NULL, opaque, NULL, true); + NULL, dev, NULL, true); } static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) @@ -398,33 +391,9 @@ static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) } break; case CHR_EVENT_CLOSED: - if (!runstate_check(RUN_STATE_SHUTDOWN)) { - /* - * A close event may happen during a read/write, but vhost - * code assumes the vhost_dev remains setup, so delay the - * stop & clear. - */ - AioContext *ctx = qemu_get_current_aio_context(); - - qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL, - NULL, NULL, false); - aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque); - - /* - * Move vhost device to the stopped state. The vhost-user device - * will be clean up and disconnected in BH. This can be useful in - * the vhost migration code. If disconnect was caught there is an - * option for the general vhost code to get the dev state without - * knowing its type (in this case vhost-user). - * - * FIXME: this is sketchy to be reaching into vhost_dev - * now because we are forcing something that implies we - * have executed vhost_dev_stop() but that won't happen - * until vhost_user_blk_stop() gets called from the bh. - * Really this state check should be tracked locally. - */ - s->dev.started = false; - } + /* defer close until later to avoid circular close */ + vhost_user_async_close(dev, &s->chardev, &s->dev, + vhost_user_blk_disconnect); break; case CHR_EVENT_BREAK: case CHR_EVENT_MUX_IN: diff --git a/hw/virtio/vhost-user-gpio.c b/hw/virtio/vhost-user-gpio.c index be9be08b4c..b7b82a1099 100644 --- a/hw/virtio/vhost-user-gpio.c +++ b/hw/virtio/vhost-user-gpio.c @@ -233,6 +233,8 @@ static int vu_gpio_connect(DeviceState *dev, Error **errp) return 0; } +static void vu_gpio_event(void *opaque, QEMUChrEvent event); + static void vu_gpio_disconnect(DeviceState *dev) { VirtIODevice *vdev = VIRTIO_DEVICE(dev); @@ -245,6 +247,11 @@ static void vu_gpio_disconnect(DeviceState *dev) vu_gpio_stop(vdev); vhost_dev_cleanup(&gpio->vhost_dev); + + /* Re-instate the event handler for new connections */ + qemu_chr_fe_set_handlers(&gpio->chardev, + NULL, NULL, vu_gpio_event, + NULL, dev, NULL, true); } static void vu_gpio_event(void *opaque, QEMUChrEvent event) @@ -262,7 +269,9 @@ static void vu_gpio_event(void *opaque, QEMUChrEvent event) } break; case CHR_EVENT_CLOSED: - vu_gpio_disconnect(dev); + /* defer close until later to avoid circular close */ + vhost_user_async_close(dev, &gpio->chardev, &gpio->vhost_dev, + vu_gpio_disconnect); break; case CHR_EVENT_BREAK: case CHR_EVENT_MUX_IN: diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index abe23d4ebe..8f635844af 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -21,6 +21,7 @@ #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "qemu/sockets.h" +#include "sysemu/runstate.h" #include "sysemu/cryptodev.h" #include "migration/migration.h" #include "migration/postcopy-ram.h" @@ -2670,6 +2671,76 @@ void vhost_user_cleanup(VhostUserState *user) user->chr = NULL; } + +typedef struct { + vu_async_close_fn cb; + DeviceState *dev; + CharBackend *cd; + struct vhost_dev *vhost; +} VhostAsyncCallback; + +static void vhost_user_async_close_bh(void *opaque) +{ + VhostAsyncCallback *data = opaque; + struct vhost_dev *vhost = data->vhost; + + /* + * If the vhost_dev has been cleared in the meantime there is + * nothing left to do as some other path has completed the + * cleanup. + */ + if (vhost->vdev) { + data->cb(data->dev); + } + + g_free(data); +} + +/* + * We only schedule the work if the machine is running. If suspended + * we want to keep all the in-flight data as is for migration + * purposes. + */ +void vhost_user_async_close(DeviceState *d, + CharBackend *chardev, struct vhost_dev *vhost, + vu_async_close_fn cb) +{ + if (!runstate_check(RUN_STATE_SHUTDOWN)) { + /* + * A close event may happen during a read/write, but vhost + * code assumes the vhost_dev remains setup, so delay the + * stop & clear. + */ + AioContext *ctx = qemu_get_current_aio_context(); + VhostAsyncCallback *data = g_new0(VhostAsyncCallback, 1); + + /* Save data for the callback */ + data->cb = cb; + data->dev = d; + data->cd = chardev; + data->vhost = vhost; + + /* Disable any further notifications on the chardev */ + qemu_chr_fe_set_handlers(chardev, + NULL, NULL, NULL, NULL, NULL, NULL, + false); + + aio_bh_schedule_oneshot(ctx, vhost_user_async_close_bh, data); + + /* + * Move vhost device to the stopped state. The vhost-user device + * will be clean up and disconnected in BH. This can be useful in + * the vhost migration code. If disconnect was caught there is an + * option for the general vhost code to get the dev state without + * knowing its type (in this case vhost-user). + * + * Note if the vhost device is fully cleared by the time we + * execute the bottom half we won't continue with the cleanup. + */ + vhost->started = false; + } +} + static int vhost_user_dev_start(struct vhost_dev *dev, bool started) { if (!virtio_has_feature(dev->protocol_features, diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h index c6e693cd3f..191216a74f 100644 --- a/include/hw/virtio/vhost-user.h +++ b/include/hw/virtio/vhost-user.h @@ -68,4 +68,22 @@ bool vhost_user_init(VhostUserState *user, CharBackend *chr, Error **errp); */ void vhost_user_cleanup(VhostUserState *user); +/** + * vhost_user_async_close() - cleanup vhost-user post connection drop + * @d: DeviceState for the associated device (passed to callback) + * @chardev: the CharBackend associated with the connection + * @vhost: the common vhost device + * @cb: the user callback function to complete the clean-up + * + * This function is used to handle the shutdown of a vhost-user + * connection to a backend. We handle this centrally to make sure we + * do all the steps and handle potential races due to VM shutdowns. + * Once the connection is disabled we call a backhalf to ensure + */ +typedef void (*vu_async_close_fn)(DeviceState *cb); + +void vhost_user_async_close(DeviceState *d, + CharBackend *chardev, struct vhost_dev *vhost, + vu_async_close_fn cb); + #endif |