Re: [PATCH v3 0/6] intel_iommu: Enable PRQ support for passthrough device

On Mon, 2026-08-10 at 10:49 +0000, Duan, Zhenzhong wrote:
> Caution: External email. Do not open attachments or click links, unless this email comes from a known sender and you know the content is safe.
> 
> 
> Hi Clement,
> 
> 
> > -----Original Message-----
> > From: Clément MATHIEU--DRIF <[[email protected]](mailto:[email protected])>
> > Subject: Re: [PATCH v3 0/6] intel_iommu: Enable PRQ support for passthrough
> > device
> > 
> > Hi Zhenzhong,
> > 
> > I will read this series early next week.
> > thanks for the respin!
> > 
> > btw, related to this work: have ever seen
> > vfio_device_get_aw_bits returning 47 whereas
> > the iommu supports 48? This leads the following
> > aw test to fail:
> > 
> > ```
> > ret = hiodc->get_cap(hiod, HOST_IOMMU_DEVICE_CAP_AW_BITS, errp);
> > if (ret < 0) {
> >    return false;
> > }
> > if (s->aw_bits > ret) {
> >    error_setg(errp, "aw-bits %d > host aw-bits %d", s->aw_bits, ret);
> >    return false;
> > }
> > ```
> > 
> > I got this when trying to nest VMs.
> 
> 
> I am trying to reproduce, what device did you passthrough?

I used edu for testing.  
An I had aw-bits=48 on both vms.  

> 
> Thanks  
> Zhenzhong