[pve-devel] [PATCH cluster/guest-common/qemu-server/manager v6 0/11] virtiofs

[Friedrich Weber]

Tested the following:

* created a mapping on a 3-node cluster, added mapping to PVE8 VM,
offline-migrated VM between cluster nodes, checked that `mount` inside
the VM mounts the correct host directory

* checked that `xattr=1` makes xattrs available in the guest, and
`acl=1` makes acls available in the guest

* added a non-privileged user with different combinations of
Mapping.Audit/Use/Modify and played around with modifying/using
directory mappings

Overall, it's working fine and I did not encounter major issues. Here
are a few things I noticed (somewhat sorted by priority in descending
order):

* after having started and stopped a VM with a shared filesystem a few
times, I noticed quite some zombie virtiofsd processes, I guess they
would need to be cleaned up:

```
root       11121  0.0  3.5 251260 140924 ?       S    14:23   0:00 task
UPID:cl2:00002B6C:00056BEE:64B68425:qmstart:100:fred at pve:
root       11125  0.0  0.0      0     0 ?        Z    14:23   0:00  \_
[virtiofsd] <defunct>
root       12064  0.0  3.5 251180 140980 ?       S    14:28   0:00 task
UPID:cl2:00002F1D:0005E581:64B6855D:qmstart:100:fred at pve:
root       12067  0.0  0.0      0     0 ?        Z    14:28   0:00  \_
[virtiofsd] <defunct>
...
```

* is it intended that the virtiofsd process is started as a child of the
qmstart task process, causing the task process to stay around as long as
the VM is up? This seemed a bit unexpected to me when I first read the
`ps` output, but also I don't know if there is a good alternative.

* in the GUI, the Add->Shared Filesystem button is greyed out if I do
not have the Sys.Console privilege, but via the API I can create the
shared filesystem without Sys.Console and with just (I think)
VM.Config.Disk and Mapping.Use. I'm not sure, but it seems like the GUI
permission check is too strict and Sys.Console should not be required?

* in the GUI, I can add multiple shared directories with the same tag
but different dirids to a VM. In a quick test, it looked like the first
one took precedence. Not sure if there should be some kind of validation
logic here checking that no two virtiofs entries use the same tag?

* in the GUI, if I add a shared filesystem, the dialog title is "Add:
Filesystem passthrough", this should probably be "Add: Shared
Filesystem" for consistency with the button text.

On 06/07/2023 12:54, Markus Frank wrote:
> cluster:
> 
> Markus Frank (1):
>   add mapping/dir.cfg for resource mapping
> 
>  src/PVE/Cluster.pm  | 1 +
>  src/pmxcfs/status.c | 1 +
>  2 files changed, 2 insertions(+)
> 
> 
> guest-common:
> 
> Markus Frank (1):
>   add DIR mapping config
> 
>  src/Makefile           |   1 +
>  src/PVE/Mapping/DIR.pm | 175 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 176 insertions(+)
>  create mode 100644 src/PVE/Mapping/DIR.pm
> 
> 
> qemu-server:
> 
> v6:
>  * added virtiofsd dependency
>  * 2 new patches:
>     * Permission check for virtiofs directory access
>     * check_local_resources: virtiofs
> 
> v5:
>  * allow numa settings with virtio-fs
>  * added direct-io & cache settings
>  * changed to rust implementation of virtiofsd
>  * made double fork and closed all file descriptor so that the lockfile
>  gets released.
> 
> v3:
>  * created own socket and get file descriptor for virtiofsd
>  so there is no race between starting virtiofsd & qemu
>  * added TODO to replace virtiofsd with rust implementation in bookworm
>  (I packaged the rust implementation for bookworm & the C implementation
>  in qemu will be removed in qemu 8.0)
> 
> v2:
>  * replaced sharedfiles_fmt path in qemu-server with dirid:
>  * user can use the dirid to specify the directory without requiring root access
> 
> Markus Frank (3):
>   feature #1027: virtio-fs support
>   Permission check for virtiofs directory access
>   check_local_resources: virtiofs
> 
>  PVE/API2/Qemu.pm         |  18 +++++
>  PVE/QemuServer.pm        | 167 ++++++++++++++++++++++++++++++++++++++-
>  PVE/QemuServer/Memory.pm |  25 ++++--
>  debian/control           |   1 +
>  4 files changed, 204 insertions(+), 7 deletions(-)
> 
> 
> manager:
> 
> v6: completly new except "ui: added options to add virtio-fs to qemu config"
> 
> Markus Frank (5):
>   api: add resource map api endpoints for directories
>   ui: add edit window for dir mappings
>   ui: ResourceMapTree for DIR
>   ui: form: add DIRMapSelector
>   ui: added options to add virtio-fs to qemu config
> 
>  PVE/API2/Cluster/Mapping.pm         |   7 +
>  PVE/API2/Cluster/Mapping/DIR.pm     | 299 ++++++++++++++++++++++++++++
>  PVE/API2/Cluster/Mapping/Makefile   |   3 +-
>  www/manager6/Makefile               |   4 +
>  www/manager6/Utils.js               |   1 +
>  www/manager6/dc/Config.js           |  10 +
>  www/manager6/dc/DIRMapView.js       |  50 +++++
>  www/manager6/form/DIRMapSelector.js |  63 ++++++
>  www/manager6/qemu/HardwareView.js   |  19 ++
>  www/manager6/qemu/VirtiofsEdit.js   | 120 +++++++++++
>  www/manager6/window/DIRMapEdit.js   | 186 +++++++++++++++++
>  11 files changed, 761 insertions(+), 1 deletion(-)
>  create mode 100644 PVE/API2/Cluster/Mapping/DIR.pm
>  create mode 100644 www/manager6/dc/DIRMapView.js
>  create mode 100644 www/manager6/form/DIRMapSelector.js
>  create mode 100644 www/manager6/qemu/VirtiofsEdit.js
>  create mode 100644 www/manager6/window/DIRMapEdit.js
>