Re: [PATCH v3 2/3] intel_iommu: fix type of the mask field in VTDIOTLBPageInvInfo

[CLEMENT MATHIEU--DRIF]

On 05/07/2024 10:51, Michael S. Tsirkin wrote:

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> On Fri, Jul 05, 2024 at 05:03:17AM +0000, CLEMENT MATHIEU--DRIF wrote:
> > From: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>
> >
> > VTDIOTLBPageInvInfo.mask might not fit in an uint8_t.
> I think what you mean is that is assigned values that might not
> fit .... it's u8 ATM so of course it fits.
What about :
"The mask stored into VTDIOTLBPageInvInfo.mask might not fit in an uint8_t. Use uint64_t to avoid overflows"

> > Moreover, this field is used in binary operations with 64-bit addresses.
> So what?
I thing the first part of the message is enough, the issue comes from the fact that the mask does not fit into the type
> > Signed-off-by: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>
> > ---
> >  hw/i386/intel_iommu_internal.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> > index cbc4030031..5fcbe2744f 100644
> > --- a/hw/i386/intel_iommu_internal.h
> > +++ b/hw/i386/intel_iommu_internal.h
> > @@ -436,7 +436,7 @@ struct VTDIOTLBPageInvInfo {
> >      uint16_t domain_id;
> >      uint32_t pasid;
> >      uint64_t addr;
> > -    uint8_t mask;
> > +    uint64_t mask;
> >  };
> >  typedef struct VTDIOTLBPageInvInfo VTDIOTLBPageInvInfo;
> >
> > --
> > 2.45.2