Re: [PATCH v2 2/4] virtio-iommu: Default to bypass during boot

[Michael S. Tsirkin]

On Tue, Feb 08, 2022 at 06:42:57PM +0100, Cornelia Huck wrote:
> On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote:
> 
> > @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState 
> > *dev, Error **errp)
> >      virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE);
> >      virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE);
> >      virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP);
> > -    virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS);
> >      virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO);
> >      virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE);
> > +    virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG);
> 
> Hm. In the other patch, you say that you don't support cross-version
> migration (I assume across QEMU versions?)

I missed that ... where does it say this?

> Because changing the feature
> set will be guest-visible, and would need some compat handling if you
> plan to support this.