"Sierra Guiza, Alejandro (Alex)" writes: > @apopple@nvidia.com Could you please check this patch? It's somehow related to > migrate_device_page() for long term device coherent pages. Sure thing. This whole series is in my queue of things to review once I make it home from LSF/MM. - Alistair > Regards, > Alex Sierra >> -----Original Message----- >> From: amd-gfx On Behalf Of Alex >> Sierra >> Sent: Thursday, May 5, 2022 4:34 PM >> To: jgg@nvidia.com >> Cc: rcampbell@nvidia.com; willy@infradead.org; david@redhat.com; >> Kuehling, Felix ; apopple@nvidia.com; amd- >> gfx@lists.freedesktop.org; linux-xfs@vger.kernel.org; linux-mm@kvack.org; >> jglisse@redhat.com; dri-devel@lists.freedesktop.org; akpm@linux- >> foundation.org; linux-ext4@vger.kernel.org; hch@lst.de >> Subject: [PATCH v1 04/15] mm: add device coherent checker to remove >> migration pte >> >> During remove_migration_pte(), entries for device coherent type pages that >> were not created through special migration ptes, ignore _PAGE_RW flag. This >> path can be found at migrate_device_page(), where valid vma is not >> required. In this case, migrate_vma_collect_pmd() is not called and special >> migration ptes are not set. >> >> Signed-off-by: Alex Sierra >> --- >> mm/migrate.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/mm/migrate.c b/mm/migrate.c index >> 6c31ee1e1c9b..e18ddee56f37 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -206,7 +206,8 @@ static bool remove_migration_pte(struct folio *folio, >> * Recheck VMA as permissions can change since migration >> started >> */ >> entry = pte_to_swp_entry(*pvmw.pte); >> - if (is_writable_migration_entry(entry)) >> + if (is_writable_migration_entry(entry) || >> + is_device_coherent_page(pfn_to_page(pvmw.pfn))) >> pte = maybe_mkwrite(pte, vma); >> else if (pte_swp_uffd_wp(*pvmw.pte)) >> pte = pte_mkuffd_wp(pte); >> -- >> 2.32.0