Re: [PATCH] hw/i386/x86-iommu: Correctly set pt bit in extended capability register

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jun 22, 2026 at 05:31:01PM +0000, Clément MATHIEU--DRIF wrote:
> Hi,
> 
> I think I have seen this patch at least twice in the list o.O
> 
> It seems it has not been merged into master yet (@Michael, do you want me to send a rebased version?).

rebased or not, I was not CC'd.


> https://patchew.org/QEMU/CAFFE2avrHDKZd5m7j3E3x5=F=pzn-3c9vzGWP3+9-AVPwQng7w@mail.gmail.com/
> 
> Thanks for the effort though ;)  
> 
> cmd

i can pick this one or wait for your patch.

> 
> On Mon, 2026-06-22 at 18:21 +0200, no92 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.
> > 
> > 
> > With the changes in c7b2e22bd957, the `pt` bit was set in the (wrong)  
> > capability register, instead of the (correct) extended capability  
> > register.
> > 
> > Fixes: c7b2e22bd95710e404c393e9f563cfe7404220c1 ("hw/i386/x86-iommu: Remove X86IOMMUState::pt_supported field")  
> > Signed-off-by: no92 <[leo@managarm.org](mailto:leo@managarm.org)>  
> > ---  
> >  hw/i386/intel_iommu.c | 4 ++--  
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c  
> > index 744cdfd2e6..d1af7a3135 100644  
> > --- a/hw/i386/intel_iommu.c  
> > +++ b/hw/i386/intel_iommu.c  
> > @@ -4988,7 +4988,7 @@ static void vtd_cap_init(IntelIOMMUState *s)  
> >  {  
> >      X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
> > 
> > -    s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND | VTD_ECAP_PT |  
> > +    s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND |  
> >               VTD_CAP_MAMV | VTD_CAP_PSI | VTD_CAP_SSLPS | VTD_CAP_DRAIN |  
> >               VTD_CAP_ESRTPS | VTD_CAP_MGAW(s->aw_bits);  
> >      if (x86_iommu->dma_translation) {  
> > @@ -4999,7 +4999,7 @@ static void vtd_cap_init(IntelIOMMUState *s)  
> >                      s->cap |= VTD_CAP_SAGAW_48bit;  
> >              }  
> >      }  
> > -    s->ecap = VTD_ECAP_QI | VTD_ECAP_IRO;  
> > +    s->ecap = VTD_ECAP_QI | VTD_ECAP_IRO | VTD_ECAP_PT;
> > 
> >      if (x86_iommu_ir_supported(x86_iommu)) {  
> >          s->ecap |= VTD_ECAP_IR | VTD_ECAP_MHMV;  
> > --  
> > 2.54.0
> >