From 296592305b2f37eae4559a4864a8281931aec303 Mon Sep 17 00:00:00 2001
From: Ralph Campbell <rcampbell@nvidia.com>
Date: Thu, 23 Jul 2020 15:30:00 -0700
Subject: mm/migrate: add a flags parameter to migrate_vma
Git-commit: 5143192cd410c4fc83be09a2e73423765aee072b
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
The src_owner field in struct migrate_vma is being used for two purposes,
it acts as a selection filter for which types of pages are to be migrated
and it identifies device private pages owned by the caller.
Split this into separate parameters so the src_owner field can be used
just to identify device private pages owned by the caller of
migrate_vma_setup().
Rename the src_owner field to pgmap_owner to reflect it is now used only
to identify which device private pages to migrate.
Link: https://lore.kernel.org/r/20200723223004.9586-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 4 +++-
include/linux/migrate.h | 13 +++++++++----
lib/test_hmm.c | 15 ++++-----------
mm/migrate.c | 6 ++++--
4 files changed, 20 insertions(+), 18 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -182,7 +182,8 @@ static vm_fault_t nouveau_dmem_migrate_t
.end = vmf->address + PAGE_SIZE,
.src = &src,
.dst = &dst,
- .src_owner = drm->dev,
+ .pgmap_owner = drm->dev,
+ .flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE,
};
/*
@@ -615,6 +616,7 @@ nouveau_dmem_migrate_vma(struct nouveau_
struct migrate_vma args = {
.vma = vma,
.start = start,
+ .flags = MIGRATE_VMA_SELECT_SYSTEM,
};
unsigned long i;
u64 *pfns;
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -180,6 +180,11 @@ static inline unsigned long migrate_pfn(
return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
}
+enum migrate_vma_direction {
+ MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
+ MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
+};
+
struct migrate_vma {
struct vm_area_struct *vma;
/*
@@ -199,11 +204,11 @@ struct migrate_vma {
/*
* Set to the owner value also stored in page->pgmap->owner for
- * migrating out of device private memory. If set only device
- * private pages with this owner are migrated. If not set
- * device private pages are not migrated at all.
+ * migrating out of device private memory. The flags also need to
+ * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
*/
- void *src_owner;
+ void *pgmap_owner;
+ unsigned long flags;
};
int migrate_vma_setup(struct migrate_vma *args);
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -585,15 +585,6 @@ static void dmirror_migrate_alloc_and_co
*/
spage = migrate_pfn_to_page(*src);
- /*
- * Don't migrate device private pages from our own driver or
- * others. For our own we would do a device private memory copy
- * not a migration and for others, we would need to fault the
- * other device's page into system memory first.
- */
- if (spage && is_zone_device_page(spage))
- continue;
-
dpage = dmirror_devmem_alloc_page(mdevice);
if (!dpage)
continue;
@@ -702,7 +693,8 @@ static int dmirror_migrate(struct dmirro
args.dst = dst_pfns;
args.start = addr;
args.end = next;
- args.src_owner = NULL;
+ args.pgmap_owner = NULL;
+ args.flags = MIGRATE_VMA_SELECT_SYSTEM;
ret = migrate_vma_setup(&args);
if (ret)
goto out;
@@ -1053,7 +1045,8 @@ static vm_fault_t dmirror_devmem_fault(s
args.end = args.start + PAGE_SIZE;
args.src = &src_pfns;
args.dst = &dst_pfns;
- args.src_owner = dmirror->mdevice;
+ args.pgmap_owner = dmirror->mdevice;
+ args.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
if (migrate_vma_setup(&args))
return VM_FAULT_SIGBUS;
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2265,7 +2265,9 @@ again:
goto next;
page = device_private_entry_to_page(entry);
- if (page->pgmap->owner != migrate->src_owner)
+ if (!(migrate->flags &
+ MIGRATE_VMA_SELECT_DEVICE_PRIVATE) ||
+ page->pgmap->owner != migrate->pgmap_owner)
goto next;
mpfn = migrate_pfn(page_to_pfn(page)) |
@@ -2273,7 +2275,7 @@ again:
if (is_write_device_private_entry(entry))
mpfn |= MIGRATE_PFN_WRITE;
} else {
- if (migrate->src_owner)
+ if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
goto next;
pfn = pte_pfn(pte);
if (is_zero_pfn(pfn)) {