cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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multi-process.rst (2089B)

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