Hi Jagannathan, On 10/15/20 8:05 PM, Jagannathan Raman wrote: > From: Elena Ufimtseva <elena.ufimts...@oracle.com>
Documentation is scarce ;) > > Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com> > Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com> > Signed-off-by: John G Johnson <john.g.john...@oracle.com> > Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > MAINTAINERS | 2 ++ > docs/multi-process.rst | 67 > ++++++++++++++++++++++++++++++++++++++++++++++ > scripts/mpqemu-launcher.py | 49 +++++++++++++++++++++++++++++++++ > 3 files changed, 118 insertions(+) > create mode 100644 docs/multi-process.rst > create mode 100755 scripts/mpqemu-launcher.py > > diff --git a/MAINTAINERS b/MAINTAINERS > index 9a911e0..d12aba7 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -3118,6 +3118,8 @@ F: include/hw/pci/memory-sync.h > F: hw/i386/remote-iohub.c > F: include/hw/i386/remote-iohub.h > F: docs/devel/multi-process.rst > +F: scripts/mpqemu-launcher.py > +F: scripts/mpqemu-launcher-perf-mode.py This one was in v7, Stefan asked about it, then the script disappeared in v8 =) https://www.mail-archive.com/qemu-devel@nongnu.org/msg718984.html > > Build and test automation > ------------------------- > diff --git a/docs/multi-process.rst b/docs/multi-process.rst > new file mode 100644 > index 0000000..c4b022c > --- /dev/null > +++ b/docs/multi-process.rst > @@ -0,0 +1,67 @@ > +Multi-process QEMU > +================== > + > +This document describes how to configure and use multi-process qemu. > +For the design document refer to docs/devel/qemu-multiprocess. > + > +1) Configuration > +---------------- > + > +To enable support for multi-process add --enable-mpqemu > +to the list of options for the "configure" script. > + > + > +2) Usage > +-------- > + > +Multi-process QEMU requires an orchestrator to launch. Please refer to a > +light-weight python based orchestrator for mpqemu in > +scripts/mpqemu-launcher.py to lauch QEMU in multi-process mode. > + > +Following is a description of command-line used to launch mpqemu. > + > +* Orchestrator: > + > + - The Orchestrator creates a unix socketpair > + > + - It launches the remote process and passes one of the > + sockets to it via command-line. > + > + - It then launches QEMU and specifies the other socket as an option > + to the Proxy device object > + > +* Remote Process: > + > + - QEMU can enter remote process mode by using the "remote" machine > + option. > + > + - The orchestrator creates a "remote-object" with details about > + the device and the file descriptor for the device > + > + - The remaining options are no different from how one launches QEMU with > + devices. > + > + - Example command-line for the remote process is as follows: > + > + /usr/bin/qemu-system-x86_64 \ > + -machine x-remote \ > + -device lsi53c895a,id=lsi0 \ > + -drive id=drive_image2,file=/build/ol7-nvme-test-1.qcow2 \ > + -device scsi-hd,id=drive2,drive=drive_image2,bus=lsi0.0,scsi-id=0 \ > + -object x-remote-object,id=robj1,devid=lsi1,fd=4, > + > +* QEMU: > + > + - Since parts of the RAM are shared between QEMU & remote process, a > + memory-backend-memfd is required to facilitate this, as follows: > + > + -object memory-backend-memfd,id=mem,size=2G > + > + - A "x-pci-proxy-dev" device is created for each of the PCI devices > emulated > + in the remote process. A "socket" sub-option specifies the other end of > + unix channel created by orchestrator. The "id" sub-option must be > specified > + and should be the same as the "id" specified for the remote PCI device > + > + - Example commandline for QEMU is as follows: > + > + -device x-pci-proxy-dev,id=lsi0,socket=3 > diff --git a/scripts/mpqemu-launcher.py b/scripts/mpqemu-launcher.py > new file mode 100755 > index 0000000..6e0ef22 > --- /dev/null > +++ b/scripts/mpqemu-launcher.py > @@ -0,0 +1,49 @@ > +#!/usr/bin/env python3 > +import socket > +import os > +import subprocess > +import time > + > +PROC_QEMU='/usr/bin/qemu-system-x86_64' If this is a (multiarch) test, then ... > + > +proxy, remote = socket.socketpair(socket.AF_UNIX, socket.SOCK_STREAM) > + > +remote_cmd = [ PROC_QEMU, > \ > + '-machine', 'x-remote', > \ > + '-device', 'lsi53c895a,id=lsi1', > \ ... I'd move it to tests/integration/multiproc-x86-lsi53c895a.py ... > + '-drive', > 'id=drive_image1,file=/build/ol7-nvme-test-1.qcow2', \ ... use avocado.utils.vmimage (see tests/acceptance/boot_linux.py) to download a prebuilt image, ... > + '-device', 'scsi-hd,id=drive1,drive=drive_image1,bus=lsi1.0,' > \ > + 'scsi-id=0', > \ > + '-object', > \ > + > 'x-remote-object,id=robj1,devid=lsi1,fd='+str(remote.fileno()), \ > + '-nographic', > \ > + ] > + > +proxy_cmd = [ PROC_QEMU, > \ > + '-name', 'OL7.4', > \ > + '-machine', 'q35,accel=kvm', > \ > + '-smp', 'sockets=1,cores=1,threads=1', > \ > + '-m', '2048', > \ > + '-object', 'memory-backend-memfd,id=sysmem-file,size=2G', > \ > + '-numa', 'node,memdev=sysmem-file', > \ > + '-device', 'virtio-scsi-pci,id=virtio_scsi_pci0', > \ > + '-drive', 'id=drive_image1,if=none,format=qcow2,' > \ > + 'file=/home/ol7-hdd-1.qcow2', > \ > + '-device', 'scsi-hd,id=image1,drive=drive_image1,' > \ > + 'bus=virtio_scsi_pci0.0', > \ > + '-boot', 'd', > \ > + '-vnc', ':0', > \ > + '-device', 'x-pci-proxy-dev,id=lsi1,fd='+str(proxy.fileno()), > \ > + ] > + > + > +pid = os.fork(); > + > +if pid: > + # In Proxy > + print('Launching QEMU with Proxy object'); > + process = subprocess.Popen(proxy_cmd, pass_fds=[proxy.fileno()]) > +else: > + # In remote > + print('Launching Remote process'); > + process = subprocess.Popen(remote_cmd, pass_fds=[remote.fileno()]) > ... and do something within the guest to be sure MultiProc works :) Regards, Phil.