VirtioFS shares unreliable

[zcutlip]

I'm finding folder sharing from the host into the guest to be unreliable using VirtIoFS, and I'm wondering if others are seeing this too.

Among the problems are changes to files are slow to propagate in both directions (changes made in the guest, as well as changes made from the host).

A particularly weird issue is that I can create a text file in the host that is readable in the guest. Then if I edit the file from the host in vim, then save, I can no longer cat the file, with the error "no such file or directory"

I assume this is because vim unlinks the original file and replaces it, resulting in a new inode, and for some reason this isn't being reflected inside the host.

This is happening for me in macOS 14.6 guests on a macOS 14.6 host, as well as macOS 15 guests on a macOS 15 host.