From: Elena Ufimtseva <elena.ufimts...@oracle.com> 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> --- docs/qemu-multiprocess.txt | 104 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 docs/qemu-multiprocess.txt
diff --git a/docs/qemu-multiprocess.txt b/docs/qemu-multiprocess.txt new file mode 100644 index 0000000..b0428da --- /dev/null +++ b/docs/qemu-multiprocess.txt @@ -0,0 +1,104 @@ +/* + * Copyright 2019, Oracle and/or its affiliates. All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + + +Multi-process QEMU + +This document describes how to configure and use multi-process qemu. +For the design document refer to docs/devel/qemu-multiprocess. + +Configure + +To enable support for multi-process add --enable-mpqemu +to the list of options for configure. + +Usage + +Command line + +To start qemu with devices intended to run in the separate emulation +process, the following options are used: + + -rdevice, -rdrive: + this is similar to -device option, with only difference being + the "rid" option that identifies the remote process. + +For exmaple, for non multi-process qemu: + -device lsi53c895a,id=scsi0 device + -device scsi-hd,drive=drive0,bus=scsi0.0,scsi-id=0 + -drive id=drive0,file=data-disk.img + +and for multi-process qemu: + -rdevice lsi53c895a,id=scsi0,rid=0 + -rdevice scsi-hd,drive=drive0,bus=scsi0.0,scsi-id=0,rid=0 + -rdrive id=drive0,file=data-disk.img,rid=0 + + +The memorybackend object has to be specified on the command line: +-object memory-backend-file,id=mem,mem-path=/dev/shm/,size=4096M,share=on + + +Example of running scsi drive in the guest in separate qemu +process: + +qemu-system-x86_64 -enable-kvm -machine q35 -smp 4 -m 4096M -vnc :0 \ +-net nic -net user,hostfwd=tcp::5022-:22 -hda os.qcow2 \ +-rdevice lsi53c895a,rid=0,id=scsi0 \ +-rdevice scsi-hd,rid=0,drive=drive0,bus=scsi0.0,scsi-id=0 \ +-rdrive id=drive0,rid=0,file=data-disk.img \ +-object memory-backend-file,id=mem,mem-path=/dev/shm/,size=4096M,share=on -numa node,memdev=mem + +HMP commands + +For hotplugging in multi-process qemu the following commands +can be used: + +- rdevice_add; +- rdevice_del; +- rdrive_add; +- rdrive_del; +- remote_proc_list + +Example: + +qemu-system-x86_64 -enable-kvm -machine q35 -smp 4 -m 4096M -vnc :0 \ +-net nic -net user,hostfwd=tcp::5022-:22 \ +-drive file=/root/ol7.qcow2,format=raw \ +-rdevice lsi53c895a,rid=0,id=scsi0 \ +-object memory-backend-file,id=mem,mem-path=/dev/shm/,size=4096M,share=on \ +-numa node,memdev=mem \ +-monitor stdio + +(qemu) rdrive_add 0 drive0 file=/root/cirros-0.4.0-x86_64-disk.img +(qemu) rdevice_add 0 scsi-hd drive1 drive0 scsi0.0 +(qemu) remote_proc_list + PID RID QEMU ID PROCESS NAME + +00011079 0 drive0 qemu-scsi-dev +00011079 0 drive1 qemu-scsi-dev +00011079 0 0 qemu-scsi-dev + +After running rescan_scsi_bus.sh -a, guest will be able to identify newly +added devices. + + + -- 1.8.3.1
