[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported
From: |
Michael S. Tsirkin |
Subject: |
Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported |
Date: |
Thu, 9 Sep 2021 04:47:42 -0400 |
On Tue, Sep 07, 2021 at 02:22:24PM +0100, Daniel P. Berrangé wrote:
> On Tue, Sep 07, 2021 at 02:49:35PM +0200, Stefano Garzarella wrote:
> > Commit 1e08fd0a46 ("vhost-vsock: SOCK_SEQPACKET feature bit support")
> > enabled the SEQPACKET feature bit.
> > This commit is released with QEMU 6.1, so if we try to migrate a VM where
> > the host kernel supports SEQPACKET but machine type version is less than
> > 6.1, we get the following errors:
> >
> > Features 0x130000002 unsupported. Allowed features: 0x179000000
> > Failed to load virtio-vhost_vsock:virtio
> > error while loading state for instance 0x0 of device
> > '0000:00:05.0/virtio-vhost_vsock'
> > load of migration failed: Operation not permitted
> >
> > Let's disable the feature bit for machine types < 6.1, adding a
> > `features` field to VHostVSock to simplify the handling of upcoming
> > features we will support.
>
> IIUC, this will still leave migration broken for anyone migrating
> a >= 6.1 machine type between a kernel that supports SEQPACKET and
> a kernel lacking that, or vica-verca.
>
> If a feature is dependant on a host kernel feature we can't turn
> that on automatically as part of the machine type, as we need
> ABI stability across migration indepdant of kernel version.
>
>
> Regards,
> Daniel
This is a fundamental problem we have with kernel accelerators.
A higher level solution at management level is needed.
For now yes, we do turn features on by default,
consistent kernels on source and destination are assumed.
For downstreams not a problem at all as they update
userspace and kernel in concert.
> --
> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o- https://fstop138.berrange.com :|
> |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
- [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Stefano Garzarella, 2021/09/07
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Daniel P . Berrangé, 2021/09/07
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported,
Michael S. Tsirkin <=
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Daniel P . Berrangé, 2021/09/09
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Michael S. Tsirkin, 2021/09/10
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Stefano Garzarella, 2021/09/13
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Michael S. Tsirkin, 2021/09/13
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Stefano Garzarella, 2021/09/14
- Re: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported, Michael S. Tsirkin, 2021/09/14