From 6eaf0e612b415877d1c411b95bed2ecb53b546bb Mon Sep 17 00:00:00 2001 From: Li Feng Date: Thu, 16 May 2024 10:57:46 +0800 Subject: [PATCH] vhost-user: fix lost reconnect again 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 fail 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. We need to ensure that even if vhost_dev_init initialization fails, the event handler still needs to be reinstalled when s->connected is false. All vhost-user devices have this issue, including vhost-user-blk/scsi. Fixes: 71e076a07d ("hw/virtio: generalise CHR_EVENT_CLOSED handling") Signed-off-by: Li Feng Message-Id: <20240516025753.130171-3-fengli@smartx.com> Reviewed-by: Raphael Norwitz Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/block/vhost-user-blk.c | 3 ++- hw/scsi/vhost-user-scsi.c | 3 ++- hw/virtio/vhost-user-base.c | 3 ++- hw/virtio/vhost-user.c | 10 +--------- 4 files changed, 7 insertions(+), 12 deletions(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 15cc24d017..fdbc30b9ce 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -354,7 +354,7 @@ static void vhost_user_blk_disconnect(DeviceState *dev) VHostUserBlk *s = VHOST_USER_BLK(vdev); if (!s->connected) { - return; + goto done; } s->connected = false; @@ -362,6 +362,7 @@ static void vhost_user_blk_disconnect(DeviceState *dev) vhost_dev_cleanup(&s->dev); +done: /* Re-instate the event handler for new connections */ qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, NULL, dev, NULL, true); diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c index 421cd654f8..cc91ade525 100644 --- a/hw/scsi/vhost-user-scsi.c +++ b/hw/scsi/vhost-user-scsi.c @@ -182,7 +182,7 @@ static void vhost_user_scsi_disconnect(DeviceState *dev) VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev); if (!s->connected) { - return; + goto done; } s->connected = false; @@ -190,6 +190,7 @@ static void vhost_user_scsi_disconnect(DeviceState *dev) vhost_dev_cleanup(&vsc->dev); +done: /* Re-instate the event handler for new connections */ qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, vhost_user_scsi_event, NULL, dev, NULL, true); diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c index 4b54255682..11e72b1e3b 100644 --- a/hw/virtio/vhost-user-base.c +++ b/hw/virtio/vhost-user-base.c @@ -225,13 +225,14 @@ static void vub_disconnect(DeviceState *dev) VHostUserBase *vub = VHOST_USER_BASE(vdev); if (!vub->connected) { - return; + goto done; } vub->connected = false; vub_stop(vdev); vhost_dev_cleanup(&vub->vhost_dev); +done: /* Re-instate the event handler for new connections */ qemu_chr_fe_set_handlers(&vub->chardev, NULL, NULL, vub_event, diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index c929097e87..c407ea8939 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -2781,16 +2781,8 @@ typedef struct { 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); - } + data->cb(data->dev); g_free(data); } -- 2.30.2