hmm_range_fault() will succeed for any kind of device private memory, even if it doesn't belong to the calling entity. While nouveau has some crude checks for that, they are broken because they assume nouveau is the only user of device private memory. Fix this by passing in an expected pgmap owner in the hmm_range_fault structure. If a device_private page is found and doesn't match the owner then it is treated as an non-present and non-faultable page. This prevents a bug in amdgpu, where it doesn't know how to handle device_private pages, but hmm_range_fault would return them anyhow.
Unified · Split
| @@ -672,12 +672,6 @@ out: · 671 unmodified lines | ||
| 672 | 672 | return ret; |
| 673 | 673 | } |
| 674 | 674 | |
| 675 | −static inline bool | |
| 676 | −nouveau_dmem_page(struct nouveau_drm *drm, struct page *page) | |
| 677 | −{ | |
| 678 | − return is_device_private_page(page) && drm->dmem == page_to_dmem(page); | |
| 679 | −} | |
| 680 | − | |
| 681 | 675 | void |
| 682 | 676 | nouveau_dmem_convert_pfn(struct nouveau_drm *drm, |
| 683 | 677 | struct hmm_range *range) |
| @@ -696,12 +690,6 @@ nouveau_dmem_convert_pfn(struct nouveau_drm *drm, · 12 unmodified lines | ||
| 696 | 690 | if (!is_device_private_page(page)) |
| 697 | 691 | continue; |
| 698 | 692 | |
| 699 | − if (!nouveau_dmem_page(drm, page)) { | |
| 700 | − WARN(1, "Some unknown device memory !\n"); | |
| 701 | − range->pfns[i] = 0; | |
| 702 | − continue; | |
| 703 | − } | |
| 704 | − | |
| 705 | 693 | addr = nouveau_dmem_page_addr(page); |
| 706 | 694 | range->pfns[i] &= ((1UL << range->pfn_shift) - 1); |
| 707 | 695 | range->pfns[i] |= (addr >> PAGE_SHIFT) << range->pfn_shift; |
| @@ -132,6 +132,7 @@ enum hmm_pfn_value_e { · 131 unmodified lines | ||
| 132 | 132 | * @pfn_flags_mask: allows to mask pfn flags so that only default_flags matter |
| 133 | 133 | * @pfn_shifts: pfn shift value (should be <= PAGE_SHIFT) |
| 134 | 134 | * @valid: pfns array did not change since it has been fill by an HMM function |
| 135 | + * @dev_private_owner: owner of device private pages | |
| 135 | 136 | */ |
| 136 | 137 | struct hmm_range { |
| 137 | 138 | struct mmu_interval_notifier *notifier; |
| @@ -144,6 +145,7 @@ struct hmm_range { · 6 unmodified lines | ||
| 144 | 145 | uint64_t default_flags; |
| 145 | 146 | uint64_t pfn_flags_mask; |
| 146 | 147 | uint8_t pfn_shift; |
| 148 | + void *dev_private_owner; | |
| 147 | 149 | }; |
| 148 | 150 | |
| 149 | 151 | /* |
| @@ -218,6 +218,14 @@ int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, · 217 unmodified lines | ||
| 218 | 218 | unsigned long end, uint64_t *pfns, pmd_t pmd); |
| 219 | 219 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
| 220 | 220 | |
| 221 | +static inline bool hmm_is_device_private_entry(struct hmm_range *range, | |
| 222 | + swp_entry_t entry) | |
| 223 | +{ | |
| 224 | + return is_device_private_entry(entry) && | |
| 225 | + device_private_entry_to_page(entry)->pgmap->owner == | |
| 226 | + range->dev_private_owner; | |
| 227 | +} | |
| 228 | + | |
| 221 | 229 | static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte) |
| 222 | 230 | { |
| 223 | 231 | if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte)) |
| @@ -256,7 +264,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, · 32 unmodified lines | ||
| 256 | 264 | * Never fault in device private pages pages, but just report |
| 257 | 265 | * the PFN even if not present. |
| 258 | 266 | */ |
| 259 | − if (is_device_private_entry(entry)) { | |
| 267 | + if (hmm_is_device_private_entry(range, entry)) { | |
| 260 | 268 | *pfn = hmm_device_entry_from_pfn(range, |
| 261 | 269 | swp_offset(entry)); |
| 262 | 270 | *pfn |= range->flags[HMM_PFN_VALID]; |