On Fri, Feb 14, 2025 at 11:07:17AM +0000, Daniel P. Berrangé wrote: > On Fri, Feb 14, 2025 at 03:03:20AM -0800, Andrea Bolognani wrote: > > How does passt know where the backing file is located in the first > > place? It's not passed on its command line, and I didn't spot any > > logic to hand the information over. This part clearly works, I just > > don't understand how :) > > IIUC the vhost user protocol passes over a pre-opened FD for > the memory region(s). In the audit log (there are some known AVC denials due to the SELinux policy not having been updated yet) I'm seeing the full path to the file, which I assume wouldn't be there if passt was only provided an FD. But QEMU does indeed know the path, so it sounds reasonable that it would be the one handing that information over to the passt process as part of setting up the vhost-user connection. -- Andrea Bolognani / Red Hat / Virtualization