[vfio-users] Awful boot times, current OVMF to blame?

[Laszlo Ersek]

On 07/25/17 10:48, Hristo Iliev wrote:
> This sounds really a lot like that old kernel MTRR problem

Yes, it does.

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=879ae1880449c88db11c1ebdaedc2da79b2fe73f

(part of v4.4)

The symptoms described in this thread (matching the commit message
above) finger the phase of the firmware where all processors are started
up initially. Moving back to ancient OVMF builds might paper over the
symptom (it's possible that those OVMF builds don't even boot up the APs
at all). Either way, the time when all APs are executing in parallel in
the firmware shouldn't show as even a blip in anyone's favorite load
monitor.

This sounds like a really messy problem and I don't think I can give any
advice until I can log into a machine that reproduces this problem --
even then, KVM tracing looks necessary, interpreting which is usually
horribly difficult (to me anyway). So, I'm specifically not asking for
kernel versions, OVMF logs and the like.

Any chance you guys can use the most recent OVMF build from Gerd's repo,
and bisect the host kernel instead? Check out the most recent releases
of a few stable / longterm kernel streams first, I guess: 4.12.3,
4.11.12, 4.9.39, 4.4.78 ...

Thanks
Laszlo