[vfio-users] Qemu 2.3 slow

[Alex Williamson]

On Thu, 2015-08-13 at 22:05 +0300, José Ramón Muñoz Pekkarinen wrote:
> 	Hi,
> 
> 	Do anyone use qemu-2.3 for vfio passthrough? I tried it and it 
> considerably slowdown the startup of the machine at unusable point, so I don't 
> really know if it's just my setup.

Unless something is incredibly wrong, like not enabling KVM, the
performance of an assigned device is fairly well independent of QEMU.
The whole idea of device assignment is to have as little interaction
with the hypervisor as possible.  If the slowdown is unrelated to the
assigned device, you should try QEMU 2.4 and report the issue to the
QEMU lists.  Thanks,

Alex