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

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 15 Nov 2021 11:57:43 -0500
Brian Rak <brak@vultr.com> wrote:

> Will this fix make it into 6.2?

yes,
it was just merged 2aa1842d6d79..7e6055c99f2f1f

PS:
Native PCIe hotplug fixes from Gerd were merged as well,
so if you'd like to use native hotplug, use 
  --global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off
to turn off ACPI hotplug.

> On 11/12/2021 3:51 PM, Igor Mammedov wrote:
> > 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
> >   https://patchew.org/QEMU/20211112110857.3116853-1-imammedo@redhat.com/
> >  
> >> Regards,
> >> Daniel  
>