From f02a4b8e6431598612466f76aac64ab492849abf Mon Sep 17 00:00:00 2001 From: Li Feng Date: Mon, 9 Oct 2023 12:47:01 +0800 Subject: [PATCH] vhost-user: fix lost reconnect When the vhost-user is reconnecting to the backend, and if the vhost-user fails at the get_features in vhost_dev_init(), then the reconnect will fail and it will not be retriggered forever. The reason is: When the vhost-user fails at get_features, the vhost_dev_cleanup will be called immediately. vhost_dev_cleanup calls 'memset(hdev, 0, sizeof(struct vhost_dev))'. The reconnect path is: vhost_user_blk_event vhost_user_async_close(.. vhost_user_blk_disconnect ..) qemu_chr_fe_set_handlers <----- clear the notifier callback schedule vhost_user_async_close_bh The vhost->vdev is null, so the vhost_user_blk_disconnect will not be called, then the event fd callback will not be reinstalled. All vhost-user devices have this issue, including vhost-user-blk/scsi. With this patch, if the vdev->vdev is null, the fd callback will still be reinstalled. Fixes: 71e076a07d ("hw/virtio: generalise CHR_EVENT_CLOSED handling") Signed-off-by: Li Feng Reviewed-by: Raphael Norwitz Message-Id: <20231009044735.941655-6-fengli@smartx.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/block/vhost-user-blk.c | 2 +- hw/scsi/vhost-user-scsi.c | 3 ++- hw/virtio/vhost-user-gpio.c | 2 +- hw/virtio/vhost-user.c | 10 ++++++++-- include/hw/virtio/vhost-user.h | 3 ++- 5 files changed, 14 insertions(+), 6 deletions(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 3c69fa47d5..95c758200d 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -391,7 +391,7 @@ static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) case CHR_EVENT_CLOSED: /* defer close until later to avoid circular close */ vhost_user_async_close(dev, &s->chardev, &s->dev, - vhost_user_blk_disconnect); + vhost_user_blk_disconnect, vhost_user_blk_event); break; case CHR_EVENT_BREAK: case CHR_EVENT_MUX_IN: diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c index 258fba5c69..4486500cac 100644 --- a/hw/scsi/vhost-user-scsi.c +++ b/hw/scsi/vhost-user-scsi.c @@ -212,7 +212,8 @@ static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event) case CHR_EVENT_CLOSED: /* defer close until later to avoid circular close */ vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev, - vhost_user_scsi_disconnect); + vhost_user_scsi_disconnect, + vhost_user_scsi_event); 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 fc784e4213..aff2d7eff6 100644 --- a/hw/virtio/vhost-user-gpio.c +++ b/hw/virtio/vhost-user-gpio.c @@ -289,7 +289,7 @@ static void vu_gpio_event(void *opaque, QEMUChrEvent event) case CHR_EVENT_CLOSED: /* defer close until later to avoid circular close */ vhost_user_async_close(dev, &gpio->chardev, &gpio->vhost_dev, - vu_gpio_disconnect); + vu_gpio_disconnect, vu_gpio_event); 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 f9414f03de..b8a7b5542d 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -2756,6 +2756,7 @@ typedef struct { DeviceState *dev; CharBackend *cd; struct vhost_dev *vhost; + IOEventHandler *event_cb; } VhostAsyncCallback; static void vhost_user_async_close_bh(void *opaque) @@ -2770,7 +2771,10 @@ static void vhost_user_async_close_bh(void *opaque) */ if (vhost->vdev) { data->cb(data->dev); - } + } else if (data->event_cb) { + qemu_chr_fe_set_handlers(data->cd, NULL, NULL, data->event_cb, + NULL, data->dev, NULL, true); + } g_free(data); } @@ -2782,7 +2786,8 @@ static void vhost_user_async_close_bh(void *opaque) */ void vhost_user_async_close(DeviceState *d, CharBackend *chardev, struct vhost_dev *vhost, - vu_async_close_fn cb) + vu_async_close_fn cb, + IOEventHandler *event_cb) { if (!runstate_check(RUN_STATE_SHUTDOWN)) { /* @@ -2798,6 +2803,7 @@ void vhost_user_async_close(DeviceState *d, data->dev = d; data->cd = chardev; data->vhost = vhost; + data->event_cb = event_cb; /* Disable any further notifications on the chardev */ qemu_chr_fe_set_handlers(chardev, diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h index 9f9ddf878d..6b06ecb1bd 100644 --- a/include/hw/virtio/vhost-user.h +++ b/include/hw/virtio/vhost-user.h @@ -106,6 +106,7 @@ 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); + vu_async_close_fn cb, + IOEventHandler *event_cb); #endif