Re: Guests wont start with 15 pcie-root-port devices

[Igor Mammedov]

On Fri, 12 Nov 2021 17:53:42 +0000
Daniel P. Berrangé <berrange@redhat.com> wrote:

> On Fri, Nov 12, 2021 at 12:35:07PM -0500, Brian Rak wrote:
> > In 6.1, a guest with 15 empty pcie-root-port devices will not boot properly
> > - it just hangs on "Guest has not initialized the display (yet).".  As soon
> > as I remove the last pcie-root-port, the guest begins starting up normally. 
> >   
> 
> Yes, QEMU 6.1 has a regression
> 
>   https://gitlab.com/qemu-project/qemu/-/issues/641 
> 
> 
> > commit e2a6290aab578b2170c1f5909fa556385dc0d820
> > Author: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> > Date:   Mon Aug 2 12:00:57 2021 +0300
> > 
> >     hw/pcie-root-port: Fix hotplug for PCI devices requiring IO
> > 
> > Although I can't say I really understand why that commit triggered it.  
> 
> It caused the firmware to always allocate I/O space for every port
> and there's limited total I/O space, so it runs out at 15 devices.

alternatively instead of reverting to native PCIe hotplug as in the issue
Daniel's mentioned, you can apply following fix
 20211112110857.3116853-1-imammedo@redhat.com/">https://patchew.org/QEMU/20211112110857.3116853-1-imammedo@redhat.com/

> 
> Regards,
> Daniel