Comment 6 for bug 1877716

On Mon, May 11, 2020 at 10:12 AM Stefan Hajnoczi <email address hidden> wrote:
> On Sat, May 9, 2020 at 9:16 AM Xavier <email address hidden> wrote:
> >
> > Public bug reported:
> >
> > On Arch Linux, the recent qemu package update seems to misbehave on some
> > systems. In my case, my Windows 10 guest runs fine for around 5 minutes
> > and then start to get really sluggish, even unresponsive. It needs to be
> > forced off. I could reproduce this on a minimal VM with no passthrough,
> > although my current testing setup involves an nvme pcie passthrough.
> >
> > I bisected it to the following commit which rapidly starts to run sluggishly on my setup:
> > https://github.com/qemu/qemu/commit/73fd282e7b6dd4e4ea1c3bbb3d302c8db51e4ccf
>
> Thanks for bisecting this bug! Arch Linux can work around it in the
> short term by building with ./configure --disable-linux-io-uring
> and/or removing the liburing build dependency.

Hmm...a brief look at the Arch Linux package source suggests QEMU is
not being built with io_uring enabled. Anatol, please confirm whether
this is correct.

If io_uring is not enabled then this bug may affect most existing
users on Linux. Initially I thought it was because Arch Linux had
enabled the new io_uring feature but I was probably mistaken.