nested 9p filesystem with security_model=mapped-xattr

[Daniel Haid]

I do not know whether this is a bug or a feature request, but on a 9p virtfs with security_model=mapped-xattr, access to extended attributes starting with "user.virtfs" coming from the guest seem to be silently ignored. Would it not be more correct to use some sort of "escaping", say map to "user.virtfs.x" on guest to "user.virtfs.virtfs.x" on host or something like that, so that the guest can use arbitrary attributes.

In particular, this would allow nested virtual machines to use nested 9p virtfs with security_model=mapped-xattr.

[Daniel Haid (d-haid)]

After looking at the code, it seems that disabling the user.virtfs namespace was the intended behaviour. I have created a patch implementing nesting instead of disabling.

I do not know if this is the right way to do it, but I did some limited testing and it seemed ok.

[Enrico Weigelt, metux IT consult (metux-its)]

Interesting approach. But maybe it should be configurable (eg. specify the mapping prefix).

[Thomas Huth (th-huth)]

Looking through old bug tickets... is this still an issue with the latest version of QEMU? Or could we close this ticket nowadays?

[Christian Schoenebeck (schoenebeck)]

The status of this issue is unchanged in QEMU, i.e. user.virtfs.* is still filtered out.

If someone wants to see this changed, please use the common way for sending the patch via ML:
https://wiki.qemu.org/Contribute/SubmitAPatch

[Thomas Huth (th-huth)]

This is an automated cleanup. This bug report has been moved to QEMU's
new bug tracker on gitlab.com and thus gets marked as 'expired' now.
Please continue with the discussion here:

 https://gitlab.com/qemu-project/qemu/-/issues/117