[PATCH v9 00/20] Initial support for multi-process Qemu

[elena . ufimtseva]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Hello

This is the v9 of the patchset. Thank you very much for the
detailed feedback for v8. We appreciate your time. We believe
we have address all the comments for v8 in the current series.
Special thanks to Stefan Hajnoczi.

The v9 has the following changes:
- Communication channel. Qemu side uses blocking call to send
  and receive the message from the remote and cannot progress
  further until the remote side replies. Enhanced the
  communication channel by dropping iothread lock before blocking
  on Qemu end. Use the co-routines on the remote end to avoid
  blocking QMP monitor;
- removed the heartbeat functionality, it will be added later
  in a full extent;
- fixed leaked errors and similar fixes;
- eliminated bytestream passing over the channel;
- The build system had to be changed in order to accomodate the
  latest changes in Qemu to use Kconfig/mason.

To touch upon the history of this project, we posted the
Proof Of Concept patches before the BoF session in 2018.
Subsequently, we posted 8 versions on the qemu-devel mailist.
You can find them by following the links below ([1] - [8]).

Following people contributed to the design and
implementation of this project:
Jagannathan Raman <jag.raman@oracle.com>
Elena Ufimtseva <elena.ufimtseva@oracle.com>
John G Johnson <john.g.johnson@oracle.com>
Stefan Hajnoczi <stefanha@redhat.com>
Konrad Wilk <konrad.wilk@oracle.com>
Kanth Ghatraju <kanth.ghatraju@oracle.com>

We would like to thank QEMU community for your feedback in the
design and implementation of this project.

Qemu wiki page:
https://wiki.qemu.org/Features/MultiProcessQEMU

For the full concept writeup about QEMU multi-process, please refer to
docs/devel/qemu-multiprocess.rst. Also see docs/qemu-multiprocess.txt for
usage information.

We welcome all your ideas, concerns, and questions for this patchset.

[POC]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg566538.html
[1]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg602285.html
[2]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg624877.html
[3]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg642000.html
[4]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg655118.html
[5]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg682429.html
[6]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg697484.html
[7]: https://patchew.org/QEMU/cover.1593273671.git.elena.ufimtseva@oracle.com/
[8]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg727007.html

Elena Ufimtseva (8):
  multi-process: add qio channel function to transmit
  multi-process: define MPQemuMsg format and transmission functions
  multi-process: define transmission functions in remote
  multi-process: introduce proxy object
  multi-process: add proxy communication functions
  multi-process: Forward PCI config space acceses to the remote process
  multi-process: perform device reset in the remote process
  multi-process: add configure and usage information

Jagannathan Raman (11):
  memory: alloc RAM from file at offset
  multi-process: Add config option for multi-process QEMU
  multi-process: setup PCI host bridge for remote device
  multi-process: setup a machine object for remote device process
  multi-process: Initialize message handler in remote device
  multi-process: Associate fd of a PCIDevice with its object
  multi-process: setup memory manager for remote device
  multi-process: PCI BAR read/write handling for proxy & remote
    endpoints
  multi-process: Synchronize remote memory
  multi-process: create IOHUB object to handle irq
  multi-process: Retrieve PCI info from remote process

John G Johnson (1):
  multi-process: add the concept description to
    docs/devel/qemu-multiprocess

 MAINTAINERS                     |  26 +
 backends/hostmem-memfd.c        |   2 +-
 configure                       |  10 +
 docs/devel/index.rst            |   1 +
 docs/devel/multi-process.rst    | 966 ++++++++++++++++++++++++++++++++
 docs/multi-process.rst          |  67 +++
 exec.c                          |  11 +-
 hw/i386/meson.build             |   5 +
 hw/i386/remote-iohub.c          | 123 ++++
 hw/i386/remote-memory.c         |  58 ++
 hw/i386/remote-msg.c            | 263 +++++++++
 hw/i386/remote-obj.c            | 140 +++++
 hw/i386/remote.c                |  79 +++
 hw/misc/ivshmem.c               |   3 +-
 hw/pci-host/meson.build         |   1 +
 hw/pci-host/remote.c            |  75 +++
 hw/pci/memory-sync.c            | 210 +++++++
 hw/pci/meson.build              |   3 +
 hw/pci/proxy.c                  | 363 ++++++++++++
 include/exec/memory.h           |   2 +
 include/exec/ram_addr.h         |   2 +-
 include/hw/i386/remote-iohub.h  |  42 ++
 include/hw/i386/remote-memory.h |  19 +
 include/hw/i386/remote-obj.h    |  42 ++
 include/hw/i386/remote.h        |  35 ++
 include/hw/pci-host/remote.h    |  31 +
 include/hw/pci/memory-sync.h    |  27 +
 include/hw/pci/pci_ids.h        |   3 +
 include/hw/pci/proxy.h          |  54 ++
 include/io/channel.h            |  24 +
 include/io/mpqemu-link.h        | 110 ++++
 include/qemu/mmap-alloc.h       |   3 +-
 io/channel.c                    |  45 ++
 io/meson.build                  |   2 +
 io/mpqemu-link.c                | 347 ++++++++++++
 meson.build                     |   1 +
 scripts/mpqemu-launcher.py      |  49 ++
 softmmu/memory.c                |   3 +-
 util/mmap-alloc.c               |   7 +-
 util/oslib-posix.c              |   2 +-
 40 files changed, 3243 insertions(+), 13 deletions(-)
 create mode 100644 docs/devel/multi-process.rst
 create mode 100644 docs/multi-process.rst
 create mode 100644 hw/i386/remote-iohub.c
 create mode 100644 hw/i386/remote-memory.c
 create mode 100644 hw/i386/remote-msg.c
 create mode 100644 hw/i386/remote-obj.c
 create mode 100644 hw/i386/remote.c
 create mode 100644 hw/pci-host/remote.c
 create mode 100644 hw/pci/memory-sync.c
 create mode 100644 hw/pci/proxy.c
 create mode 100644 include/hw/i386/remote-iohub.h
 create mode 100644 include/hw/i386/remote-memory.h
 create mode 100644 include/hw/i386/remote-obj.h
 create mode 100644 include/hw/i386/remote.h
 create mode 100644 include/hw/pci-host/remote.h
 create mode 100644 include/hw/pci/memory-sync.h
 create mode 100644 include/hw/pci/proxy.h
 create mode 100644 include/io/mpqemu-link.h
 create mode 100644 io/mpqemu-link.c
 create mode 100755 scripts/mpqemu-launcher.py

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2.25.GIT