]>
Commit | Line | Data |
---|---|---|
2c46bc24 AB |
1 | .. _Multi-process QEMU: |
2 | ||
639090d8 EU |
3 | Multi-process QEMU |
4 | ================== | |
5 | ||
6 | This document describes how to configure and use multi-process qemu. | |
7771e8b8 | 7 | For the design document refer to docs/devel/multi-process.rst. |
639090d8 EU |
8 | |
9 | 1) Configuration | |
10 | ---------------- | |
11 | ||
12 | multi-process is enabled by default for targets that enable KVM | |
13 | ||
14 | ||
15 | 2) Usage | |
16 | -------- | |
17 | ||
18 | Multi-process QEMU requires an orchestrator to launch. | |
19 | ||
20 | Following is a description of command-line used to launch mpqemu. | |
21 | ||
22 | * Orchestrator: | |
23 | ||
24 | - The Orchestrator creates a unix socketpair | |
25 | ||
26 | - It launches the remote process and passes one of the | |
27 | sockets to it via command-line. | |
28 | ||
29 | - It then launches QEMU and specifies the other socket as an option | |
30 | to the Proxy device object | |
31 | ||
32 | * Remote Process: | |
33 | ||
34 | - QEMU can enter remote process mode by using the "remote" machine | |
35 | option. | |
36 | ||
37 | - The orchestrator creates a "remote-object" with details about | |
38 | the device and the file descriptor for the device | |
39 | ||
40 | - The remaining options are no different from how one launches QEMU with | |
41 | devices. | |
42 | ||
43 | - Example command-line for the remote process is as follows: | |
44 | ||
45 | /usr/bin/qemu-system-x86_64 \ | |
46 | -machine x-remote \ | |
47 | -device lsi53c895a,id=lsi0 \ | |
48 | -drive id=drive_image2,file=/build/ol7-nvme-test-1.qcow2 \ | |
49 | -device scsi-hd,id=drive2,drive=drive_image2,bus=lsi0.0,scsi-id=0 \ | |
45b09cb1 | 50 | -object x-remote-object,id=robj1,devid=lsi0,fd=4, |
639090d8 EU |
51 | |
52 | * QEMU: | |
53 | ||
54 | - Since parts of the RAM are shared between QEMU & remote process, a | |
55 | memory-backend-memfd is required to facilitate this, as follows: | |
56 | ||
57 | -object memory-backend-memfd,id=mem,size=2G | |
58 | ||
59 | - A "x-pci-proxy-dev" device is created for each of the PCI devices emulated | |
60 | in the remote process. A "socket" sub-option specifies the other end of | |
61 | unix channel created by orchestrator. The "id" sub-option must be specified | |
62 | and should be the same as the "id" specified for the remote PCI device | |
63 | ||
64 | - Example commandline for QEMU is as follows: | |
65 | ||
66 | -device x-pci-proxy-dev,id=lsi0,socket=3 |