Re: [PATCH 0/2] Enable virtio-fs on s390x

[Dr. David Alan Gilbert]

* Michael S. Tsirkin (mst@redhat.com) wrote:
> On Thu, Jul 30, 2020 at 04:07:29PM +0200, Marc Hartmayer wrote:
> > This patch series is about enabling virtio-fs on s390x. For that we need
> >  + some shim code (first patch), and we need
> >  + libvhost-user to deal with virtio endiannes for non-legacy virtio
> >    devices as mandated by the spec.
> > 
> > How to use?
> > 
> > For general instructions how to use virtio-fs (on x86) please have a
> > look at https://virtio-fs.gitlab.io/howto-qemu.html. Most of the
> > instructions can also be applied on s390x.
> > 
> > In short:
> > 
> > 1. Install self-compiled QEMU with this patch series applied
> > 2. Prepare host and guest kernel so they support virtio-fs
> > 
> > Start virtiofsd on the host
> > 
> >  $ virtiofsd -f --socket-path=/tmp/vhostqemu -o source=/tmp/shared
> > 
> > Now you can start QEMU in a separate shell on the host:
> > 
> >  $ qemu-system-s390x -machine 
> > type=s390-ccw-virtio,accel=kvm,memory-backend=mem \
> >    -object 
> > memory-backend-file,id=mem,size=2G,mem-path=/dev/shm/virtiofs,share=on,prealloc=on,prealloc-threads=1
> >  \
> >    -chardev socket,id=char0,path=/tmp/vhostqemu -device 
> > vhost-user-fs-ccw,queue-size=1024,chardev=char0,tag=myfs \
> >    -drive if=virtio,file=disk.qcow2 \
> >    -m 2G -smp 2 -nographic
> > 
> > Log into the guest and mount it
> > 
> >  $ mount -t virtiofs myfs /mnt
> 
> Who's merging this? My tree?

I think so; it seems either generic virtio or s390 more than actually
virtiofs specific in most of it.

Dave

> > Changelog:
> >  RFC v2 -> v1:
> >  - patch 1:
> >   + Added `force_revision_1 = true` (Conny)
> >   + I didn't add the r-b from Stefan Hajnoczi as I've added the
> >     changes suggested by Conny
> >  - squashed patches 2 and 3:
> >   + removed assertion in performance critical code path (Stefan)
> >   + dropped all dead code (Stefan)
> >   + removed libvhost-access.h
> >   
> >  RFC v1 -> RFC v2:
> >   + rebased
> >   + drop patch "libvhost-user: print invalid address on vu_panic" as it's 
> > not related to this series
> >   + drop patch "[RFC 4/4] HACK: Hard-code the libvhost-user.o-cflags for 
> > s390x"
> >   + patch "virtio: add vhost-user-fs-ccw device": replace 
> > qdev_set_parent_bus and object_property_set_bool by qdev_realize
> >   + patch "libvhost-user: handle endianness as mandated by the spec":
> >     Drop support for legacy virtio devices
> >   + add patch to fence legacy virtio devices
> > *** BLURB HERE ***
> > 
> > Halil Pasic (1):
> >   virtio: add vhost-user-fs-ccw device
> > 
> > Marc Hartmayer (1):
> >   libvhost-user: handle endianness as mandated by the spec
> > 
> >  contrib/libvhost-user/libvhost-user.c | 77 +++++++++++++++------------
> >  hw/s390x/Makefile.objs                |  1 +
> >  hw/s390x/vhost-user-fs-ccw.c          | 75 ++++++++++++++++++++++++++
> >  3 files changed, 119 insertions(+), 34 deletions(-)
> >  create mode 100644 hw/s390x/vhost-user-fs-ccw.c
> > 
> > -- 
> > 2.25.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK