Messages in this thread Patch in this message | | | Subject | Re: [PATCH] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page | From | Lu Baolu <> | Date | Wed, 19 Feb 2020 11:15:36 +0800 |
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Hi Yonghyun,
Thanks for the patch.
On 2020/2/19 6:23, 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@google.com> > --- > drivers/iommu/intel-iommu.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 0c8d81f56a30..ed6e69adb578 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -5555,13 +5555,20 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, > struct dma_pte *pte; > int level = 0; > u64 phys = 0; > + const unsigned long pfn = iova >> VTD_PAGE_SHIFT;
Why do you need a "const unsigned long" here?
> > if (dmar_domain->flags & DOMAIN_FLAG_LOSE_CHILDREN) > return 0; > > - pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level); > - if (pte) > + pte = pfn_to_dma_pte(dmar_domain, pfn, &level); > + if (pte) { > phys = dma_pte_addr(pte); > + if (level > 1) > + phys += (pfn & > + ((1UL << level_to_offset_bits(level)) - 1)) > + << VTD_PAGE_SHIFT; > + phys += iova & (VTD_PAGE_SIZE - 1);
How about
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 9dc37672bf89..bd17c2510bb2 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -5693,8 +5693,14 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, u64 phys = 0;
pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level); - if (pte) + if (pte) { + unsigned long offset_mask; + + offset_mask = BIT_MASK(level_to_offset_bits(level) + + VTD_PAGE_SHIFT) - 1; phys = dma_pte_addr(pte); + phys += iova & (bitmask - 1); + }
return phys; } Best regards, baolu
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