There is a bug found in vml2 xgmi logic: mtype is always sent as NC on the VMC to TC interface for a page walk, regardless of whether the request is being sent to local or remote GPU. NC means non-coherent and will cause the VMC return data to be cached in the TCC (versus UC – uncached will not cache the data). Since the page table updates are being done by SDMA/HDP, then TCC will never be updated and the GC VML2 will continue to hit on the TCC and never get the updated page tables and result in a fault. Heave weigh tlb invalidation does a WB/INVAL of the L1/L2 GL data caches so TCC will not be hit on next request Signed-off-by: shaoyunl <Shaoyun.Liu@amd.com> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>