[v3,00/33] tools: enable xenstore-stubdom to use 9pfs

Message

Jürgen Groß Jan. 4, 2024, 9 a.m. UTC

This series is adding 9pfs support to Xenstore-stubdom, enabling it
to do logging to a dom0 directory.

This is a prerequisite for the final goal to add live update support
to Xenstore-stubdom, as it enables the stubdom to store its state in
a dom0 file.

The 9pfs backend is a new daemon written from scratch. Using a
dedicated 9pfs daemon has several advantages:

- it is using much less resources than a full blown qemu process
- it can serve multiple guests (the idea is to use it for other
  infrastructure domains, like qemu-stubdom or driver domains, too)
- it is designed to support several security enhancements, like
  limiting the number of files for a guest, or limiting the allocated
  file system space
- it doesn't support file links (neither hard nor soft links) or
  referencing parent directories via "..", minimizing the risk that
  a guest can "escape" from its home directory

Note that for now the daemon only contains the minimal needed
functionality to do logging from Xenstore-stubdom. I didn't want to
add all the 9pfs commands and security add-ons in the beginning, in
order to avoid needless efforts in case the idea of the daemon is
being rejected.

Changes in V3:
- new patches 1, 23-25
- addressed review comments

Changes in V2:
- support of multiple rings per device
- xenlogd->xen-9pfsd rename
- addressed review comments
- fixed some bugs

Juergen Gross (33):
  tools: add access macros for unaligned data
  xen/public: add some more 9pfs xenstore paths
  tools: add a new xen logging daemon
  tools/xenlogd: connect to frontend
  tools/xenlogd: add transport layer
  tools/xenlogd: add 9pfs response generation support
  tools/xenlogd: add 9pfs version request support
  tools/xenlogd: add 9pfs attach request support
  tools/xenlogd: add 9pfs walk request support
  tools/xenlogd: add 9pfs open request support
  tools/xenlogd: add 9pfs clunk request support
  tools/xenlogd: add 9pfs create request support
  tools/xenlogd: add 9pfs stat request support
  tools/xenlogd: add 9pfs write request support
  tools/xenlogd: add 9pfs read request support
  tools/libs/light: add backend type for 9pfs PV devices
  tools/xl: support new 9pfs backend xen-9pfsd
  tools/helpers: allocate xenstore event channel for xenstore stubdom
  tools/xenstored: rename xenbus_evtchn()
  stubdom: extend xenstore stubdom configs
  tools: add 9pfs device to xenstore-stubdom
  tools/xenstored: add early_init() function
  tools/xenstored: move systemd handling to posix.c
  tools/xenstored: move all log-pipe handling into posix.c
  tools/xenstored: move all socket handling into posix.c
  tools/xenstored: get own domid in stubdom case
  tools/xenstored: rework ring page (un)map functions
  tools/xenstored: split domain_init()
  tools/xenstored: map stubdom interface
  tools/xenstored: mount 9pfs device in stubdom
  tools/xenstored: add helpers for filename handling
  tools/xenstored: support complete log capabilities in stubdom
  tools/xenstored: have a single do_control_memreport()

 docs/man/xl.cfg.5.pod.in                      |   36 +-
 stubdom/xenstore-minios.cfg                   |    2 +-
 stubdom/xenstorepvh-minios.cfg                |    2 +-
 tools/Makefile                                |    1 +
 tools/golang/xenlight/helpers.gen.go          |   10 +
 tools/golang/xenlight/types.gen.go            |   12 +
 tools/helpers/init-xenstore-domain.c          |    9 +
 .../Linux/init.d/sysconfig.xencommons.in      |    1 -
 tools/hotplug/Linux/launch-xenstore.in        |    1 +
 tools/include/libxl.h                         |   17 +
 tools/include/xen-tools/common-macros.h       |   17 +
 tools/libs/light/libxl_9pfs.c                 |  174 +-
 tools/libs/light/libxl_create.c               |    4 +-
 tools/libs/light/libxl_dm.c                   |    2 +-
 tools/libs/light/libxl_types.idl              |   11 +
 tools/libs/light/libxl_types_internal.idl     |    1 +
 tools/xen-9pfsd/.gitignore                    |    1 +
 tools/xen-9pfsd/Makefile                      |   38 +
 tools/xen-9pfsd/io.c                          | 1467 +++++++++++++++++
 tools/xen-9pfsd/xen-9pfsd.c                   |  798 +++++++++
 tools/xen-9pfsd/xen-9pfsd.h                   |   99 ++
 tools/xenstored/Makefile.common               |    4 -
 tools/xenstored/control.c                     |   29 +-
 tools/xenstored/core.c                        |  250 +--
 tools/xenstored/core.h                        |   35 +-
 tools/xenstored/domain.c                      |   81 +-
 tools/xenstored/domain.h                      |    2 +
 tools/xenstored/lu_daemon.c                   |    4 +-
 tools/xenstored/minios.c                      |   93 +-
 tools/xenstored/posix.c                       |  251 ++-
 tools/xl/xl_parse.c                           |   36 +
 xen/include/public/io/9pfs.h                  |   34 +
 32 files changed, 3197 insertions(+), 325 deletions(-)
 create mode 100644 tools/xen-9pfsd/.gitignore
 create mode 100644 tools/xen-9pfsd/Makefile
 create mode 100644 tools/xen-9pfsd/io.c
 create mode 100644 tools/xen-9pfsd/xen-9pfsd.c
 create mode 100644 tools/xen-9pfsd/xen-9pfsd.h

Comments

Andrew Cooper Jan. 5, 2024, 3:20 p.m. UTC | #1

On 04/01/2024 9:00 am, Juergen Gross wrote:
>   tools: add a new xen logging daemon
>   tools/xenlogd: connect to frontend
>   tools/xenlogd: add transport layer
>   tools/xenlogd: add 9pfs response generation support
>   tools/xenlogd: add 9pfs version request support
>   tools/xenlogd: add 9pfs attach request support
>   tools/xenlogd: add 9pfs walk request support
>   tools/xenlogd: add 9pfs open request support
>   tools/xenlogd: add 9pfs clunk request support
>   tools/xenlogd: add 9pfs create request support
>   tools/xenlogd: add 9pfs stat request support
>   tools/xenlogd: add 9pfs write request support
>   tools/xenlogd: add 9pfs read request support

These all need s/logd/9pfsd/, although I think mostly in the subject only.

Can be fixed on commit, because some of them look like they're otherwise
ready to go in.

~Andrew

Anthony PERARD Jan. 15, 2024, 3:42 p.m. UTC | #2

On Fri, Jan 05, 2024 at 03:20:11PM +0000, Andrew Cooper wrote:
> On 04/01/2024 9:00 am, Juergen Gross wrote:
> >   tools: add a new xen logging daemon
> >   tools/xenlogd: connect to frontend
> >   tools/xenlogd: add transport layer
> >   tools/xenlogd: add 9pfs response generation support
> >   tools/xenlogd: add 9pfs version request support
> >   tools/xenlogd: add 9pfs attach request support
> >   tools/xenlogd: add 9pfs walk request support
> >   tools/xenlogd: add 9pfs open request support
> >   tools/xenlogd: add 9pfs clunk request support
> >   tools/xenlogd: add 9pfs create request support
> >   tools/xenlogd: add 9pfs stat request support
> >   tools/xenlogd: add 9pfs write request support
> >   tools/xenlogd: add 9pfs read request support
> 
> These all need s/logd/9pfsd/, although I think mostly in the subject only.
> 
> Can be fixed on commit, because some of them look like they're otherwise
> ready to go in.

For all these patch, with the subject fixed:
Acked-by: Anthony PERARD <[e-mail]>

Cheers,