Am Mittwoch, dem 26.03.2025 um 12:50 +1100 schrieb Balbir Singh: > On 3/26/25 10:43, Balbir Singh wrote: > > On 3/26/25 10:21, Bert Karwatzki wrote: > > > Am Mittwoch, dem 26.03.2025 um 09:45 +1100 schrieb Balbir Singh: > > > > > > > > > > > > The second region seems to be additional, I suspect that is HMM mapping > > > > from kgd2kfd_init_zone_device() > > > > > > > > Balbir Singh > > > > > > > Good guess! I inserted a printk into kgd2kfd_init_zone_device(): > > > > > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > > > b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > > > index d05d199b5e44..201220e2ac42 100644 > > > --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > > > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > > > @@ -1049,6 +1049,8 @@ int kgd2kfd_init_zone_device(struct amdgpu_device > > > *adev) > > > pgmap->range.end = res->end; > > > pgmap->type = MEMORY_DEVICE_PRIVATE; > > > } > > > + dev_info(adev->dev, "%s: range.start = 0x%llx ranges.end = > > > 0x%llx\n", > > > + __func__, pgmap->range.start, pgmap->range.end); > > > > > > pgmap->nr_range = 1; > > > pgmap->ops = &svm_migrate_pgmap_ops; > > > > > > > > > and get this in the case without nokaslr: > > > > > > [ T367] amdgpu 0000:03:00.0: kfd_migrate: kgd2kfd_init_zone_device: > > > range.start = 0xafe00000000 ranges.end = 0xaffffffffff > > > > > > and this in the case with nokaslr: > > > > > > [ T365] amdgpu 0000:03:00.0: kfd_migrate: kgd2kfd_init_zone_device: > > > range.start = 0x3ffe00000000 ranges.end = 0x3fffffffffff > > > > > > > So we should ignore the second region then for the purposes of this issue. > > > > I think this now boils down to > > > > Why is the dma_get_required_mask set to all of addressable memory (46 bits) > > when we have nokaslr > > > > I think I know the root cause of the required_mask going up and hence the > use of DMA32 > > 1. HMM calls add_pages() > 2. add_pages calls update_end_of_memory_vars() > 3. This updates max_pfn and that causes required_mask to go up to 46 bits > > Do you have CONFIG_HSA_AMD_SVM enabled? Does turning it off, fix the issue? > > The actual issue is the update of max_pfn. > > Balbir Singh >
Yes, turning off CONFIG_HSA_AMD_SVM fixes the issue, the strange memory resource afe00000000-affffffffff : 0000:03:00.0 is gone. If one would add a max_pyhs_addr argument to devm_request_free_mem_region() (which return the resource addr in kgd2kfd_init_zone_device()) one could keep the memory below the 44bit limit with CONFIG_HSA_AMD_SVM enabled. Bert Karwatzki
