Add Liu Changpeng.
On Thu, Oct 14, 2021 at 8:49 PM Li Feng <fen...@smartx.com> wrote: > > Thanks, > Feng Li > > On Thu, Oct 14, 2021 at 8:28 PM Maxime Coquelin > <maxime.coque...@redhat.com> wrote: > > > > > > > > On 10/14/21 14:12, Li Feng wrote: > > > On Thu, Oct 14, 2021 at 8:01 PM Maxime Coquelin > > > <maxime.coque...@redhat.com> wrote: > > >> > > >> Hi Li, > > >> > > >> The commit message is not compliant with the contributors guidelines: > > >> https://doc.dpdk.org/guides/contributing/patches.html#commit-messages-subject-line > > > OK, I got it. > > >> > > >> On 9/3/21 10:02, Li Feng wrote: > > >>> Vhost-user client must send the mem table, kick fd, call fd on all > > >>> virtqueues, then the device will be VIRTIO_DEV_RUNNING. > > >>> > > >>> If the vhost-user communication is initialized partly, e.g. > > >>> - When initializing the vhost-user, try to restart the vhost-user > > >>> backend; > > >>> - Seabios only initialized the vhost-scsi req vq. > > >>> The device is not with flags VIRTIO_DEV_RUNNING.. > > >>> > > >>> Root Cause: > > >>> The vhost session has been created, and added the scsi/blk requestq > > >>> poller into reactor, but when destroying the device, the requestq is not > > >>> unregistered. > > >>> > > >>> Reproduce the crash on spdk vhost-user backend: > > >>> 1. Create a VM; > > >>> 2. Mount a ISO to a VM, start the VM, don't install the OS; > > >>> 3. Restart the spdk_tgt; > > >>> > > >>> Another discusstion is in seabiso: > > >>> https://patchew.org/Seabios/20210831122339.2591585-1-fen...@smartx.com/ > > >> > > >> This is a fix, so you need to add the Fixes tag and cc stable. > > > Acked. > > > > > >> > > >>> Signed-off-by: Li Feng <fen...@smartx.com> > > >>> --- > > >>> v2: > > >>> Fix the commit msg typo: vas -> virtqueues. > > >>> -- > > >>> lib/vhost/vhost.c | 2 +- > > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > > >>> > > >>> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c > > >>> index 355ff37651..191ba82c41 100644 > > >>> --- a/lib/vhost/vhost.c > > >>> +++ b/lib/vhost/vhost.c > > >>> @@ -710,8 +710,8 @@ vhost_destroy_device_notify(struct virtio_net *dev) > > >>> if (vdpa_dev) > > >>> vdpa_dev->ops->dev_close(dev->vid); > > >>> dev->flags &= ~VIRTIO_DEV_RUNNING; > > >>> - dev->notify_ops->destroy_device(dev->vid); > > >>> } > > >>> + dev->notify_ops->destroy_device(dev->vid); > > >> > > >> .destroy_device() is the counter-part of .new_device(). > > >> VIRTIO_DEV_RUNNING is set only when .new_device() has been called with > > >> success, and cleared when .destroy_device() is called. > > >> > > >> So I disagree with the fix, we want to keep the correlation between > > >> VIRTIO_DEV_RUNNING and .new_device()/.destroy_device(). Doing otherwise > > >> could lead to regressions with other applications than yours. > > >> > > >> What is not clear from the commit message or the discussion you link is > > >> where does it crash exactly. Is it in SPDK, in DPDK? > > > > > > The crash is in SPDK, the poller is still running in the reactor, > > > however, the device is freed. > > > > > > I really don't have a good method to handle this partly initialized virt > > > queues. > > > This is another patch I prepared to fix this issue: > > > > > > From 63142ec60088d08b27b9657640b82e837557b5d4 Mon Sep 17 00:00:00 2001 > > > From: Li Feng <fen...@smartx.com> > > > Date: Wed, 1 Sep 2021 16:51:44 +0800 > > > Subject: [PATCH] vhost: fix vhost session crash > > > > > > If any vq is inited well, treat the dev is RUNNING status. > > > > > > Root Cause: > > > The session has been created, and added the requestq poller into > > > reactor, but when destroying the device, the requestq is not > > > unregistered. > > > The seabios only initialized the req vq(idx = 2), ignore the controlq > > > and eventq vq. > > > > > > Reproduce: > > > 1. Create a VM; > > > 2. Mount a ISO to a VM, start the VM, don't install the OS; > > > 3. Restart the zbs-chunkd; > > > > > > Signed-off-by: Li Feng <fen...@smartx.com> > > > Change-Id: I21292e58b0b08237b5d105359095ec6a31907752 > > > --- > > > lib/librte_vhost/vhost_user.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c > > > index f211ec8..a80e9f4 100644 > > > --- a/lib/librte_vhost/vhost_user.c > > > +++ b/lib/librte_vhost/vhost_user.c > > > @@ -1394,9 +1394,11 @@ virtio_is_ready(struct virtio_net *dev) > > > "kickfd: %d callfd: %d enabled: %d\n", > > > dev->ifname, vq, i, vq->desc, vq->avail, > > > vq->used, vq->kickfd, vq->callfd, vq->enabled); > > > - if (!vq_is_ready(dev, vq)) > > > - return 0; > > > + if (vq_is_ready(dev, vq)) > > > + break; > > > } > > > + if (i == nr_vring) > > > + return 0; > > > > > > /* If supported, ensure the frontend is really done with config */ > > > if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)) > > > > > > > Above patch will also cause regression, as networking backends work > > with queue pairs. > > > > So your issue is that SPDK is processing vrings while DPDK considers the > > device as not running. Instead of working around that issue, maybe what > > you should do is to introduce a new API and mechanism to help DPDK > > determine whether it should consider the device ready based on the > > backend type. IIUC, in your Vhost-scsi case, it should be as soon as VQ > > 2 is ready? > > Yes, VQ 2 is ready, the vhost-iscsi device should be ready. > I had this idea months ago, if it's acceptable, I will try to do it. > > Thanks. > > > > > > > > >
