On Tue, May 19, 2020 at 07:54:50PM +0200, Jean-Philippe Brucker wrote: > ARMv8.1 extensions added Virtualization Host Extensions (VHE), which allow > to run a host kernel at EL2. When using normal DMA, Device and CPU address > spaces are dissociated, and do not need to implement the same > capabilities, so VHE hasn't been used in the SMMU until now. > > With shared address spaces however, ASIDs are shared between MMU and SMMU, > and broadcast TLB invalidations issued by a CPU are taken into account by > the SMMU. TLB entries on both sides need to have identical exception level > in order to be cleared with a single invalidation. > > When the CPU is using VHE, enable VHE in the SMMU for all STEs. Normal DMA > mappings will need to use TLBI_EL2 commands instead of TLBI_NH, but > shouldn't be otherwise affected by this change. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> > --- > drivers/iommu/arm-smmu-v3.c | 31 ++++++++++++++++++++++++++----- > 1 file changed, 26 insertions(+), 5 deletions(-) Acked-by: Will Deacon <will@xxxxxxxxxx> Will
