Hi Joerg, [Cc'ing stable@xxxxxxxxxxxxxxx per Nadav's suggestion] This bug fix seems to have gotten the necessary reviews (AMD and previous commit author). Is it eligible to be applied? Thanks, Jon On Wed, Apr 26, 2023 at 1:32 PM Jon Pan-Doh <pandoh@xxxxxxxxxx> wrote: > > When running on an AMD vIOMMU, we observed multiple invalidations (of > decreasing power of 2 aligned sizes) when unmapping a single page. > > Domain flush takes gather bounds (end-start) as size param. However, > gather->end is defined as the last inclusive address (start + size - 1). > This leads to an off by 1 error. > > With this patch, verified that 1 invalidation occurs when unmapping a > single page. > > Fixes: a270be1b3fdf ("iommu/amd: Use only natural aligned flushes in a VM") > Signed-off-by: Jon Pan-Doh <pandoh@xxxxxxxxxx> > Tested-by: Sudheer Dantuluri <dantuluris@xxxxxxxxxx> > Suggested-by: Gary Zibrat <gzibrat@xxxxxxxxxx> > --- > drivers/iommu/amd/iommu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c > index 5a505ba5467e..da45b1ab042d 100644 > --- a/drivers/iommu/amd/iommu.c > +++ b/drivers/iommu/amd/iommu.c > @@ -2378,7 +2378,7 @@ static void amd_iommu_iotlb_sync(struct iommu_domain *domain, > unsigned long flags; > > spin_lock_irqsave(&dom->lock, flags); > - domain_flush_pages(dom, gather->start, gather->end - gather->start, 1); > + domain_flush_pages(dom, gather->start, gather->end - gather->start + 1, 1); > amd_iommu_domain_flush_complete(dom); > spin_unlock_irqrestore(&dom->lock, flags); > } > -- > 2.40.0.634.g4ca3ef3211-goog >