> From: David Stevens <steve...@chromium.org> > Sent: Wednesday, March 16, 2022 1:07 PM > > From: David Stevens <steve...@chromium.org> > > Fall back to domain selective flush if the target address is not aligned > to the mask being used for invalidation. This is necessary because page
using domain selective flush is a bit conservative. What about trying mask+1 first? > selective invalidation masks out the lower order bits of the target > address based on the mask value, so if a non-aligned address is targeted > for psi, then mappings at the end of [pfn, pfn+pages) may not properly > be flushed from the iotlb. > > This is not normally an issue because iova.c always allocates iovas that > are aligned to their size. However, iovas which come from other sources > (e.g. userspace via VFIO) may not be aligned. > > Signed-off-by: David Stevens <steve...@chromium.org> > --- > drivers/iommu/intel/iommu.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index 5b196cfe9ed2..c122686e0a5c 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -1735,7 +1735,8 @@ static void iommu_flush_iotlb_psi(struct > intel_iommu *iommu, > * and the base address is naturally aligned to the size. > */ > if (!cap_pgsel_inv(iommu->cap) || > - mask > cap_max_amask_val(iommu->cap)) > + mask > cap_max_amask_val(iommu->cap) || > + unlikely(((1 << mask) - 1) & pfn)) > iommu->flush.flush_iotlb(iommu, did, 0, 0, > > DMA_TLB_DSI_FLUSH); > else > -- > 2.35.1.723.g4982287a31-goog _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
