On Mon, Nov 27, 2023 at 05:25:42PM -0300, Fabiano Rosas wrote: > Hi, > > In this v3: > > Added support for the "file:/dev/fdset/" syntax to receive multiple > file descriptors. This allows the management layer to open the > migration file beforehand and pass the file descriptors to QEMU. We > need more than one fd to be able to use O_DIRECT concurrently with > unaligned writes. > > Dropped the auto-pause capability. That discussion was kind of > stuck. We can revisit optimizations for non-live scenarios once the > series is more mature/merged. > > Changed the multifd incoming side to use a more generic data structure > instead of MultiFDPages_t. This allows multifd to restore the ram > using larger chunks. > > The rest are minor changes, I have noted them in the patches > themselves.
Fabiano, Could you always keep a section around in the cover letter (and also in the upcoming doc file fixed-ram.rst) on the benefits of this feature? Please bare with me - I can start to ask silly questions. I thought it was about "keeping the snapshot file small". But then when I was thinking the use case, iiuc fixed-ram migration should always suggest the user to stop the VM first before migration starts, then if the VM is stopped the ultimate image shouldn't be large either. Or is it about performance only? Where did I miss? Thanks, -- Peter Xu
