Re: [PATCH] intel-iommu: fix Read DMAR IQA REG DW

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

On Thu, Jul 04, 2024 at 02:54:00PM +0800, Yee Li wrote:
> Sorry, the patch missing "((  ))"
> Replace "& VTD_IQA_QS" with "& (VTD_IQA_QS | VTD_IQA_DW_MASK))" is correct.
> Revised patch as follows,
> 

So submit it properly.
Also, how did you test the patch?

> Signed-off-by: yeeli <seven.yi.lee@gmail.com>




> ---
>  hw/i386/intel_iommu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 37c21a0aec..23562ba26b 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2938,7 +2938,8 @@ static uint64_t vtd_mem_read(void *opaque,
> hwaddr addr, unsigned size)
> 
>      /* Invalidation Queue Address Register, 64-bit */
>      case DMAR_IQA_REG:
> -        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & VTD_IQA_QS);
> +        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & (VTD_IQA_QS
> +                    | VTD_IQA_DW_MASK));


This is a very messy way to write this.
Align things properly pls.

>          if (size == 4) {
>              val = val & ((1ULL << 32) - 1);
>          }
> -- 
> 2.34.1
> 
> YeeLi <seven.yi.lee@gmail.com> 于2024年7月4日周四 11:53写道：
> >
> > From: yeeli <seven.yi.lee@gmail.com>
> >
> > When dmar_readq or devmem2 read the DW of IQA always 0UL because
> > "& VTD_IQA_QS". So, try to fix it.
> >
> > case:
> > after vtd_mem_write
> > IQA val: 0x100206801
> >
> > after vtd_mem_read
> > IQA val: 0x100206001
> >
> > Signed-off-by: yeeli <seven.yi.lee@gmail.com>
> > ---
> >  hw/i386/intel_iommu.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> > index 37c21a0aec..e230a45940 100644
> > --- a/hw/i386/intel_iommu.c
> > +++ b/hw/i386/intel_iommu.c
> > @@ -2938,7 +2938,8 @@ static uint64_t vtd_mem_read(void *opaque, hwaddr addr, unsigned size)
> >
> >      /* Invalidation Queue Address Register, 64-bit */
> >      case DMAR_IQA_REG:
> > -        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & VTD_IQA_QS);
> > +        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & VTD_IQA_QS
> > +                | VTD_IQA_DW_MASK);
> >          if (size == 4) {
> >              val = val & ((1ULL << 32) - 1);
> >          }
> > --
> > 2.34.1
> >