Re: [PATCH 0/9] vhost-user: support any POSIX system (tested on macOS and FreeBSD)

[Stefano Garzarella]

I just noticed that I forgot to add RFC tag and fix Author to match
SOB in some patches, sorry!

Stefano

On Wed, Feb 28, 2024 at 12:48 PM Stefano Garzarella <sgarzare@redhat.com> wrote:
>
> The vhost-user protocol is not really Linux-specific, so let's try support
> QEMU's frontends and backends (including libvhost-user) in any POSIX system
> with this series. The main use case is to be able to use virtio devices that
> we don't have built-in in QEMU (e.g. virtiofsd, vhost-user-vsock, etc.) even
> in non-Linux systems.
>
> The first 5 patches are more like fixes discovered at runtime on macOS or
> FreeBSD that could go even independently of this series.
>
> Patches 6, 7, and 8 enable building of frontends and backends (including
> libvhost-user) with associated code changes to succeed in compilation.
>
> The latest patch (9) adds support for the POSIX shm_open() API to create
> shared memory which is identified by an fd that can be shared with vhost-user
> backends. This is useful on those systems (like macOS) where we don't have
> memfd_create() or special filesystems like "/dev/shm".
>
> I put the whole series in RFC because I have some questions especially in
> patch 6 and 9, but in general any comment/suggestion/test are really welcome.
>
> Maybe the first 5 patches can go separately, but I only discovered those
> problems after testing patches 6 - 9, so I have included them in this series
> for now. Please let me know if you prefer that I send them separately.
>
> For now I tested this series using vhost-user-blk and QSD on
> macOS Sonoma 14.3.1 (aarch64), FreeBSD 14 (x86_64), and Fedora 39 (x86_64)
> in this way:
>
> - Start vhost-user-blk or QSD (same commands for all systems)
>
>   vhost-user-blk -s /tmp/vhost.socket \
>     -b Fedora-Cloud-Base-39-1.5.x86_64.raw
>
>   qemu-storage-daemon \
>     --blockdev 
> file,filename=Fedora-Cloud-Base-39-1.5.x86_64.qcow2,node-name=file \
>     --blockdev qcow2,file=file,node-name=qcow2 \
>     --export 
> vhost-user-blk,addr.type=unix,addr.path=/tmp/vhost.socket,id=vub,num-queues=1,node-name=qcow2,writable=on
>
> - macOS (aarch64): start QEMU (using hvf accelerator)
>
>   qemu-system-aarch64 -smp 2 -cpu host -M virt,accel=hvf,memory-backend=mem \
>     -drive 
> file=./build/pc-bios/edk2-aarch64-code.fd,if=pflash,format=raw,readonly=on \
>     -device virtio-net-device,netdev=net0 -netdev user,id=net0 \
>     -device ramfb -device usb-ehci -device usb-kbd \
>     -object 
> memory-backend-file,mem-path="/mem0",shm=on,share=on,id=mem,size=512M \
>     -device vhost-user-blk-pci,num-queues=1,disable-legacy=on,chardev=char0 \
>     -chardev socket,id=char0,path=/tmp/vhost.socket
>
> - FreeBSD (x86_64): start QEMU (no accelerators available)
>
>   qemu-system-x86_64 -smp 2 -M q35,memory-backend=mem \
>     -object 
> memory-backend-file,mem-path="/mem0",shm=on,share=on,id=mem,size="512M" \
>     -device vhost-user-blk-pci,num-queues=1,chardev=char0 \
>     -chardev socket,id=char0,path=/tmp/vhost.socket
>
> - Fedora (x86_64): start QEMU (using kvm accelerator)
>
>   qemu-system-x86_64 -smp 2 -M q35,accel=kvm,memory-backend=mem \
>     -object 
> memory-backend-file,mem-path="/mem0",shm=on,share=on,id=mem,size="512M" \
>     -device vhost-user-blk-pci,num-queues=1,chardev=char0 \
>     -chardev socket,id=char0,path=/tmp/vhost.socket
>
> Thanks,
> Stefano
>
> Stefano Garzarella (9):
>   libvhost-user: set msg.msg_control to NULL when it is empty
>   libvhost-user: fail vu_message_write() if sendmsg() is failing
>   libvhost-user: mask F_INFLIGHT_SHMFD if memfd is not supported
>   vhost-user-server: don't abort if we can't set fd non-blocking
>   contrib/vhost-user-blk: fix bind() using the right size of the address
>   vhost-user: enable frontends on any POSIX system
>   libvhost-user: enable it on any POSIX system
>   contrib/vhost-user-blk: enabled it on any POSIX system
>   hostmem-file: support POSIX shm_open()
>
>  meson.build                               |  5 +-
>  qapi/qom.json                             |  4 ++
>  subprojects/libvhost-user/libvhost-user.h |  2 +-
>  backends/hostmem-file.c                   | 57 ++++++++++++++++-
>  contrib/vhost-user-blk/vhost-user-blk.c   | 23 +++++--
>  hw/net/vhost_net.c                        |  8 ++-
>  subprojects/libvhost-user/libvhost-user.c | 76 ++++++++++++++++++++++-
>  util/vhost-user-server.c                  |  6 +-
>  backends/meson.build                      |  2 +-
>  hw/block/Kconfig                          |  2 +-
>  qemu-options.hx                           | 10 ++-
>  util/meson.build                          |  4 +-
>  12 files changed, 179 insertions(+), 20 deletions(-)
>
> --
> 2.43.2
>