On Fri, Apr 17, 2020 at 01:14:00PM +0800, ni.xun.in...@gmail.com wrote: > > From: Ni Xun <richar...@tencent.com> > > when reconnecting to vhost server, it doesn't send slave fd to vhost > as the slave fd is only sent in vhost_user_init. also resend the slave fd > in vhost reconnect. >
I don’t think that’s correct. See vhost_user_init() here: https://git.qemu.org/?p=qemu.git;a=blob;f=hw/virtio/vhost-user.c;h=08e7e63790e5bcfae6cd31bf9ccd32c3a7347f4e;hb=HEAD#l1898 Rather, vhost_setup_slave_channel() is called by vhost_user_backend_init(), which is called on every reconnect inside vhost_dev_init(). see vhost_user_blk_connect(): https://git.qemu.org/?p=qemu.git;a=blob;f=hw/block/vhost-user-blk.c;h=17df5338e77c684175a86e882b508849c246e78a;hb=HEAD#l297 and vhost_dev_init():https://git.qemu.org/?p=qemu.git;a=blob;f=hw/virtio/vhost.c;h=01ebe12f28e9d7e3150375dda6f55b6b8f04a42a;hb=HEAD#l1224 Note that the dev->vq_index is also set to 0 right before the vhost_dev_init() call. I tested myself and saw a VHOST_USER_SET_SLAVE_REQ_FD message sent on each reconnect with the vhost-user-blk sample. Are you seeing different behavior? If so, please provide more details on your setup? > > diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c > index 17df5338e7..59650a570b 100644 > --- a/hw/block/vhost-user-blk.c > +++ b/hw/block/vhost-user-blk.c > @@ -138,6 +138,12 @@ static int vhost_user_blk_start(VirtIODevice *vdev) > error_report("Error get inflight: %d", -ret); > goto err_guest_notifiers; > } What's the justification for sending the slave fd here? Please elaborate. > + } else { > + ret = vhost_setup_slave_channel(&s->dev); > + if (ret < 0) { > + error_report("Error setting vhost slave channel: %d", -ret); > + return ret; > + } > } > diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h > index 085450c6f8..cad60ad521 100644 > --- a/include/hw/virtio/vhost.h > +++ b/include/hw/virtio/vhost.h Why expose this through vhost.h? This is vhost-user specific. > @@ -100,6 +100,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice > *vdev); > void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev); > int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); > void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); > +int vhost_setup_slave_channel(struct vhost_dev *hdev); > > /* Test and clear masked event pending status. > * Should be called after unmask to avoid losing events. > -- > 2.24.1 (Apple Git-126) > >
