On (Sat) 27 Apr 2013 [21:15:54], Richard W.M. Jones wrote:
On Tue, Apr 23, 2013 at 11:27:09AM +0530, Amit Shah wrote:
> Hello,
>
> Fedora has carried flow control patches for qemu chardevs since a very
> long time now. They weren't upstream, and they were required for
> spice, usb-redir to work properly and not freeze the guest.
>
> Upstream qemu has now merged an alternative implementation of the same
> concept, and most of the bugs have been shaken out upstream (we don't
> know of any known bugs now). So I'm of the view we should replace
> the older patches in F19's qemu with the backport of the newer,
> upstream ones.
>
> Is this fine? I can work with Cole / Hans who have been keeping the
> older patches uptodate on Fedora to replace the patches.
Would this affect virtio-serial (ie. libguestfs)?
Yes, it affects everything that uses chardevs, including
virtio-serial. Without the flow control patches, guest writes to
virtio-serial ports could freeze the guest. We've carried
non-upstream patches in Fedora for a long time now.
Amit