Re: [PATCH v2] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page

[Lu Baolu]

Hi,

On 2020/2/22 21:05, Lu Baolu wrote:
> Hi,
>
> On 2020/2/21 3:44, Yonghyun Hwang wrote:
> > intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a 
> > huge
> > page onto its corresponding physical address. This commit fixes the 
> > bug by
> > accomodating the level of page entry for the IOVA and adds IOVA's lower
> > address to the physical address.
> >
> > Signed-off-by: Yonghyun Hwang <yonghyun@xxxxxxxxxx>
>
> This fix looks good to me.
>
> Cc: <stable@xxxxxxxxxx> # As far back as possible

The email address should be: stable@xxxxxxxxxxxxxxxx

Sorry about the typo.

Best regards,
baolu

> Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>
> Best regards,
> baolu
>
> > ---
> >
> > Changes from v1:
> > - level cannot be 0. So, the condition, "if (level > 1)", is removed, 
> > which results in a simple code.
> > - a macro, BIT_MASK, is used to have a bit mask
> >
> > ---
> > Â drivers/iommu/intel-iommu.c | 4 +++-
> > Â 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> > index 932267f49f9a..4fd5c6287b6d 100644
> > --- a/drivers/iommu/intel-iommu.c
> > +++ b/drivers/iommu/intel-iommu.c
> > @@ -5554,7 +5554,9 @@ static phys_addr_t 
> > intel_iommu_iova_to_phys(struct iommu_domain *domain,
> > ÂÂÂÂÂ pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
> > ÂÂÂÂÂ if (pte)
> > -ÂÂÂÂÂÂÂ phys = dma_pte_addr(pte);
> > +ÂÂÂÂÂÂÂ phys = dma_pte_addr(pte) +
> > +ÂÂÂÂÂÂÂÂÂÂÂ (iova & (BIT_MASK(level_to_offset_bits(level) +
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ VTD_PAGE_SHIFT) - 1));
> > ÂÂÂÂÂ return phys;
> > Â }