Re: [PATCH] intel_iommu: Check address mask before using it in pasid-based iotlb invalidation

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

On Fri, Jul 24, 2026 at 08:08:50AM +0200, Philippe Mathieu-Daudé wrote:
> On 15/7/26 15:27, Clément MATHIEU--DRIF wrote:
> > Prevent a buggy driver to execute malformed invalidation operations.
> > 
> > Add the same assert as in vtd_iotlb_page_invalidate.
> > 
> > Link: https://gitlab.com/qemu-project/qemu/-/work_items/3619
> > Fixes: 6ebe6cf2a066 ("intel_iommu: Process PASID-based iotlb invalidation")
> > Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@bull.com>
> > ---
> >   hw/i386/intel_iommu.c | 9 +++++++++
> >   1 file changed, 9 insertions(+)
> > 
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> > index bf4f0f2f6b..c591d1db3f 100644
> > --- a/hw/i386/intel_iommu.c
> > +++ b/hw/i386/intel_iommu.c
> > @@ -3021,6 +3021,8 @@ static void vtd_piotlb_page_invalidate(IntelIOMMUState *s, uint16_t domain_id,
> >   {
> >       VTDIOTLBPageInvInfo info;
> > +    assert(am <= VTD_MAMV);
> > +
> >       info.domain_id = domain_id;
> >       info.pasid = pasid;
> >       info.addr = addr;
> > @@ -3060,6 +3062,13 @@ static bool vtd_process_piotlb_desc(IntelIOMMUState *s,
> >       case VTD_INV_DESC_PIOTLB_PSI_IN_PASID:
> >           am = VTD_INV_DESC_PIOTLB_AM(inv_desc->val[1]);
> > +        if (am > VTD_MAMV) {
> > +            error_report_once("%s: invalid piotlb inv desc: hi=0x%"PRIx64
> > +                              ", lo=0x%"PRIx64" (am=%u > VTD_MAMV=%u)",
> > +                              __func__, inv_desc->val[1], inv_desc->val[0],
> > +                              am, (unsigned)VTD_MAMV);
> 
> Better use the PRIu64 format instead of this surprising cast,

I think you mean %llu - PRIu64 is for uint64_t

> anyway:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
> 
> > +            return false;
> > +        }
> >           addr = (hwaddr) VTD_INV_DESC_PIOTLB_ADDR(inv_desc->val[1]);
> >           vtd_piotlb_page_invalidate(s, domain_id, pasid, addr, am,
> >                                      VTD_INV_DESC_PIOTLB_IH(inv_desc));