This RFC 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.
libvhost-access.h is based on hw/virtio/virtio-access.h. 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 Changelog: v1->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 Halil Pasic (1): virtio: add vhost-user-fs-ccw device Marc Hartmayer (2): libvhost-user: handle endianness as mandated by the spec libvhost-user: fence legacy virtio devices contrib/libvhost-user/libvhost-access.h | 71 ++++++++++++++ contrib/libvhost-user/libvhost-user.c | 125 +++++++++++++----------- hw/s390x/Makefile.objs | 1 + hw/s390x/vhost-user-fs-ccw.c | 73 ++++++++++++++ 4 files changed, 211 insertions(+), 59 deletions(-) create mode 100644 contrib/libvhost-user/libvhost-access.h create mode 100644 hw/s390x/vhost-user-fs-ccw.c -- 2.25.4
