[pve-devel] [PATCH cluster/guest-common/docs/qemu-server/manager v15 0/12] virtiofs

[Daniel Kral]

On 4/3/25 12:34, Markus Frank wrote:
> Virtio-fs is a shared file system that enables sharing a directory
> between host and guest VMs. It takes advantage of the locality of
> virtual machines and the hypervisor to get a higher throughput than
> the 9p remote file system protocol.
> 
> build-order:
> 1. cluster
> 2. guest-common
> 3. docs
> 4. qemu-server
> 5. manager
> 
> I did not get virtiofsd to run with run_command without creating
> zombie processes after stutdown. So I replaced run_command with exec
> for now. Maybe someone can find out why this happens.
> 
> changes in v15:
> * removed announce-submounts option altogether and always set it for
>   virtiofsd.
> * added die if both memory hotplug and virtiofs are enabled
> * added fstab entry example in the docs
> * assert_valid_map_list: only run assert_valid for the mappings on the
>   current node
> * see individual patches

Gave this another look and spin with the same setup as yesterday (single 
node and the three mentioned Debian/Fedora/Win11 VMs) and a 3 node test 
cluster to also test the remaining parts in a cluster setting with 
migration.

=== Migration tests ===

Tested that offline migration and live migration is blocked correctly, 
if the resource is not available on another node, i.e. whether there is 
a dir mapping on another node.

If I try to live migrate a VM from one node to another, where the target 
does not have a dir mapping defined, I get the following precondition 
errors in the WebGUI:

- Can't migrate VM with local resources: virtiofs
- Can't migrate running VM with mapped resources: virtiofs0, virtiofs1
- Mapped Resources (virtiofs1) not available on selected target

And on the CLI:

- can't migrate VM which uses local devices: virtiofs

If I try to migrate a VM from one node to another, where the target does 
not have a dir mapping defined, I get the following precondition errors 
in the WebGUI:

- Mapped Resources (virtiofs1) not available on selected target

And on the CLI:

- can't migrate to 'node2': missing mapped devices virtiofs1

=== Config tests ===

Otherwise, I did the same tests with xattr / POSIX ACLs as before and 
this worked just as before. Also the existence of the dir mapping path 
on the current node is asserted correctly, but in a multi-node setting 
this could still be improved, see my comments inline.

Otherwise, there were some undefined variables warnings and some 
warnings that could be improved, I also noted them in my comments inline.