[v1] hw/i386/x86-iommu: Correctly set pt bit in extended capability register

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

Posted by no92 via qemu development 1 month ago

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>
---
 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

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

Posted by Yi Liu 1 month ago

On 6/23/26 00:21, no92 wrote:
> 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")

nit: c7b2e22bd957 12bits

> Signed-off-by: no92 <leo@managarm.org>
> ---
>   hw/i386/intel_iommu.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Yi Liu <yi.l.liu@intel.com>

> 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;

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

Posted by Clément MATHIEU--DRIF 1 month ago

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?).

https://patchew.org/QEMU/CAFFE2avrHDKZd5m7j3E3x5=F=pzn-3c9vzGWP3+9-AVPwQng7w@mail.gmail.com/

Thanks for the effort though ;)  

cmd


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
>

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

Posted by Michael S. Tsirkin 1 month ago

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
> >

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

Posted by Clément MATHIEU--DRIF 1 month ago


On Mon, 2026-06-22 at 15:44 -0400, Michael S. Tsirkin 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.
>
>
> 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.
>

Uh, indeed.

Pick whichever one you want, not a big deal.

In all cases:
Reviewed-by: Clement Mathieu--Drif <clement.mathieu--drif@bull.com>

Thanks Michael

>
>
> > [https://patchew.org/QEMU/CAFFE2avrHDKZd5m7j3E3x5=F=pzn-3c9vzGWP3+9-AVPwQng7w@mail.gmail.com/](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)](mailto:[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
> > >
> >
>
>