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authorElena Ufimtseva <elena.ufimtseva@oracle.com>2021-01-29 11:46:03 -0500
committerStefan Hajnoczi <stefanha@redhat.com>2021-02-09 20:53:56 +0000
commit639090d85057e7e8251e2509fa136f1a2384f131 (patch)
tree84687e83b3ffcbd7cbbe2e62a8e5aecb2f3f1ceb /docs
parent8684f1be6f2235a7672a9256b4494cb5d3ef292b (diff)
multi-process: add configure and usage information
Adds documentation explaining the command-line arguments needed to use multi-process. Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Signed-off-by: John G Johnson <john.g.johnson@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 49f757a84e5dd6fae14b22544897d1124c5fdbad.1611938319.git.jag.raman@oracle.com [Move orphan docs/multi-process.rst document into docs/system/ and add it to index.rst to prevent Sphinx "document isn't included in any toctree" error. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'docs')
-rw-r--r--docs/system/index.rst1
-rw-r--r--docs/system/multi-process.rst64
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diff --git a/docs/system/index.rst b/docs/system/index.rst
index d40f72c92b..625b494372 100644
--- a/docs/system/index.rst
+++ b/docs/system/index.rst
@@ -34,6 +34,7 @@ Contents:
pr-manager
targets
security
+ multi-process
deprecated
removed-features
build-platforms
diff --git a/docs/system/multi-process.rst b/docs/system/multi-process.rst
new file mode 100644
index 0000000000..46bb0cafc2
--- /dev/null
+++ b/docs/system/multi-process.rst
@@ -0,0 +1,64 @@
+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
+----------------
+
+multi-process is enabled by default for targets that enable KVM
+
+
+2) Usage
+--------
+
+Multi-process QEMU requires an orchestrator to launch.
+
+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