Re: [PATCH v2 0/2] s390x: support virtio-mem-pci

[David Hildenbrand <david@redhat.com>]

On 21.02.25 09:26, David Hildenbrand wrote:
> On 21.02.25 00:24, Michael S. Tsirkin wrote:
>> On Tue, Jan 28, 2025 at 07:57:03PM +0100, David Hildenbrand wrote:
>>> This is based-on [1], which adds MSI-X support to virtio-balloon-pci,
>>> but can be applied independently.
>>>
>>> Turns out it is fairly easy to get virtio-mem-pci running on s390x. We
>>> only have to add MSI-X support to virtio-mem-pci, and wire-up the
>>> (un)plugging in the machine.
>>>
>>> Tried some simple stuff (hotplug/hotunplug/resize/reboot), and all seems
>>> to be working as expected.
>>>
>>> The kernel in the VM needs both, CONFIG_VIRTIO_PCI and CONFIG_VIRTIO_MEM
>>> for it to work.
>>>
>>> [1] https://lkml.kernel.org/r/20250115161425.246348-1-arbab@linux.ibm.com
>>
>>
>> Fails CI:
>>
>> https://gitlab.com/mstredhat/qemu/-/jobs/9202574981
> 
> Hm, I thought the CI was happy when Thomas sent it upstream.
> 
> CRITICAL: log: qemu-system-i386: -device virtio-mem-pci: can't apply
> global virtio-mem-pci.vectors=0: Property 'virtio-mem-pci.vectors' not found
> 
> And the same for the virtio-balloon devices with a similar change.
> 
> Trying to run one offending cmdline on current upstream:
> 
> ./qemu-system-i386 -display none -vga none -S -machine
> pc-q35-8.0,accel=tcg -device virtio-mem-pci
> qemu-system-i386: -device virtio-mem-pci: the configuration is not
> prepared for memory devices (e.g., for memory hotplug), consider
> specifying the maxmem option
> 
> 
> So I am not sure what is happening here? Is some commit in the pipeline
> breaking this?

Note that these two patches, and the virtio-balloon-pci MSI-X
one are already upstream, Thomas included them in his s390 MR. I see 
that you have them included on your branch:

https://gitlab.com/mstredhat/qemu/-/commits/v03b-20-02-2025?ref_type=heads

The following commit in that tree is messed up:

* virtio-mem-pci: Allow setting nvectors, so we can use MSI-X

Likely, you can just drop these two patches from your tree; they are 
alreayd upstream.

-- 
Cheers,

David / dhildenb