Re: [PATCH 08/12] iommu/vt-d: Use cache_tag_flush_range() in cache_invalidate_user

[Baolu Lu]

On 3/28/24 3:54 PM, Tian, Kevin wrote:
> > From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Monday, March 25, 2024 10:17 AM
> >
> > @@ -166,9 +122,9 @@ static int intel_nested_cache_invalidate_user(struct
> > iommu_domain *domain,
> >   			break;
> >   		}
> >
> > -		intel_nested_flush_cache(dmar_domain, inv_entry.addr,
> > -					 inv_entry.npages,
> > -					 inv_entry.flags &
> > IOMMU_VTD_INV_FLAGS_LEAF);
> > +		cache_tag_flush_range(dmar_domain, inv_entry.addr,
> > +				      inv_entry.npages,
> > +				      inv_entry.flags &
> > IOMMU_VTD_INV_FLAGS_LEAF);
>
> the helper requires an 'end' address but 'npages' is incorrectly used here.

Oh yes! Thanks for pointing this out. I will fix it like below.

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index c139524274b9..cef997c07158 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1050,6 +1050,12 @@ static inline unsigned long 
aligned_nrpages(unsigned long host_addr, size_t size
        return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
 }

+/* Return a size from number of VTD pages. */
+static inline unsigned long nrpages_to_size(unsigned long npages)
+{
+       return npages << VTD_PAGE_SHIFT;
+}
+
 /* Convert value to context PASID directory size field coding. */
 #define context_pdts(pds)      (((pds) & 0x7) << 9)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index e251507cfcc0..ffbd8d98a3b8 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -123,7 +123,7 @@ static int intel_nested_cache_invalidate_user(struct 
iommu_domain *domain,
                }

                cache_tag_flush_range(dmar_domain, inv_entry.addr,
-                                     inv_entry.npages,
+                                     inv_entry.addr + 
nrpages_to_size(inv_entry.npages) - 1,
                                      inv_entry.flags & 
IOMMU_VTD_INV_FLAGS_LEAF);
                processed++;
        }

Best regards,
baolu