On Mon, Jul 08, 2024 at 03:12:27PM +0800, Yi Liu wrote:
> On 2024/7/5 19:01, CLEMENT MATHIEU--DRIF wrote:
> > From: Clément Mathieu--Drif <clement.mathieu--d...@eviden.com>
> >
> > The mask we are trying to store into VTDIOTLBPageInvInfo.mask might not
> > fit in an uint8_t. Use uint64_t to avoid overflows
>
> Per the below code, it can overflow as am can be larger than 8 according
> to the CH 6.5.2.3 IOTLB Invalidate.
I don't understand what you are saying. What can overflow?
Are you suggesting text for commit log here?
> And you may want a fix tag as well.
why not.
> info.mask = ~((1 << am) - 1);
>
> CH 6.5.2.3 IOTLB Invalidate
>
> Address Mask (AM): For page-selective-within-domain invalidations, the
> Address Mask specifies
> the number of low order bits of the ADDR field that must be masked for the
> invalidation operation.
> This field enables software to request invalidation of contiguous mappings
> for size-aligned
> regions. Refer to Table 19 for encodings of this field. When invalidating a
> large-page translation,
> software must use the appropriate Address Mask value (0 for 4KByte page, 9
> for 2-MByte page,
> and 18 for 1-GByte page). Hardware implementations report the maximum
> supported address
> mask value through the Capability register
>
> > Signed-off-by: Clément Mathieu--Drif <clement.mathieu--d...@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 faea23e8d6..5f32c36943 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;
>
> --
> Regards,
> Yi Liu
