On Tue Feb 10, 2026 at 11:27 PM EST, Paul Vixie wrote: > Do both p9fs and virtiofs both support mmap() such that two or more guests, > and the host, can all map a file on the host for read/write access, and each > see writes made by the others? This is my pain point with nfs and smb. >
The virtiofs protocol supports this, it was one of its initial selling points. However, I'm planning on implementing the extention after the base driver is merged. So not now but soon, there will be the ability to directly map data directly into the guest and work on it. A nice description of how the protocol actually does the mapping is in the commit for the Linux virtiofs kernel driver: https://lwn.net/Articles/813807/ > Is either one as lightweight as zvol and ufs, such that I could consider > using it for the os? > People have used it as a root mount but I don't have concrete numbers to be honest. I will get some this weekend and get back to you. > I appreciate all the effort both teams have put in. Thank you! > Paul Vixie
