v1: https://patchew.org/QEMU/20240228114759.44758-1-sgarz...@redhat.com/
v2: https://patchew.org/QEMU/20240326133936.125332-1-sgarz...@redhat.com/
v3: https://patchew.org/QEMU/20240404122330.92710-1-sgarz...@redhat.com/
v4:
- rebased on master (commit e116b92d01c2cd75957a9f8ad1d4932292867b81)
- added patch 6 to move using QEMU bswap helper functions in a separate
patch (Phil)
- fail if we find "share=off" in shm_backend_memory_alloc() (David)
- added Phil's R-b and David's A-b
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, 8, and 9 enable building of frontends and backends (including
libvhost-user) with associated code changes to succeed in compilation.
Patch 10 adds `memory-backend-shm` that uses 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".
Patches 11 and 12 use `memory-backend-shm` in some vhost-user tests.
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.
I tested this series using vhost-user-blk and QSD on macOS Sonoma 14.4
(aarch64), FreeBSD 14 (x86_64), OpenBSD 7.4 (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-shm,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/OpenBSD (x86_64): start QEMU (no accelerators available)
qemu-system-x86_64 -smp 2 -M q35,memory-backend=mem \
-object memory-backend-shm,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-shm,size="512M" \
-device vhost-user-blk-pci,num-queues=1,chardev=char0 \
-chardev socket,id=char0,path=/tmp/vhost.socket
Branch pushed (and CI started) at
https://gitlab.com/sgarzarella/qemu/-/tree/macos-vhost-user?ref_type=heads
Thanks,
Stefano
Stefano Garzarella (12):
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: do not set memory fd non-blocking
contrib/vhost-user-blk: fix bind() using the right size of the address
contrib/vhost-user-*: use QEMU bswap helper functions
vhost-user: enable frontends on any POSIX system
libvhost-user: enable it on any POSIX system
contrib/vhost-user-blk: enable it on any POSIX system
hostmem: add a new memory backend based on POSIX shm_open()
tests/qtest/vhost-user-blk-test: use memory-backend-shm
tests/qtest/vhost-user-test: add a test case for memory-backend-shm
docs/system/devices/vhost-user.rst | 5 +-
meson.build | 5 +-
qapi/qom.json | 17 +++
subprojects/libvhost-user/libvhost-user.h | 2 +-
backends/hostmem-shm.c | 123 ++++++++++++++++++++++
contrib/vhost-user-blk/vhost-user-blk.c | 27 +++--
contrib/vhost-user-input/main.c | 16 +--
hw/net/vhost_net.c | 5 +
subprojects/libvhost-user/libvhost-user.c | 76 ++++++++++++-
tests/qtest/vhost-user-blk-test.c | 2 +-
tests/qtest/vhost-user-test.c | 23 ++++
util/vhost-user-server.c | 12 +++
backends/meson.build | 1 +
hw/block/Kconfig | 2 +-
qemu-options.hx | 13 +++
util/meson.build | 4 +-
16 files changed, 305 insertions(+), 28 deletions(-)
create mode 100644 backends/hostmem-shm.c
--
2.45.0
