Add a new src_owner field to struct migrate_vma. If the field is set,
only device private pages with page->pgmap->owner equal to that field
are migrated. If the field is not set only "normal" pages are migrated.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Fixes: df6ad69838fc ("mm/device-public-memory: device memory cache coherent with CPU")
---
arch/powerpc/kvm/book3s_hv_uvmem.c | 1 +
drivers/gpu/drm/nouveau/nouveau_dmem.c | 1 +
include/linux/migrate.h | 8 ++++++++
mm/migrate.c | 9 ++++++---
4 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 67fefb03b9b7..f44f6b27950f 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -563,6 +563,7 @@ kvmppc_svm_page_out(struct vm_area_struct *vma, unsigned long start,
mig.end = end;
mig.src = &src_pfn;
mig.dst = &dst_pfn;
+ mig.src_owner = &kvmppc_uvmem_pgmap;
mutex_lock(&kvm->arch.uvmem_lock);
/* The requested page is already paged-out, nothing to do */
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index a4682272586e..0e36345d395c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -176,6 +176,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
.end = vmf->address + PAGE_SIZE,
.src = &src,
.dst = &dst,
+ .src_owner = drm->dev,
};
/*
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 72120061b7d4..3e546cbf03dd 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -196,6 +196,14 @@ struct migrate_vma {
unsigned long npages;
unsigned long start;
unsigned long end;
+
+ /*
+ * 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.
+ */
+ void *src_owner;
};
int migrate_vma_setup(struct migrate_vma *args);
diff --git a/mm/migrate.c b/mm/migrate.c
index b1092876e537..7605d2c23433 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2241,7 +2241,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
arch_enter_lazy_mmu_mode();
for (; addr < end; addr += PAGE_SIZE, ptep++) {
- unsigned long mpfn, pfn;
+ unsigned long mpfn = 0, pfn;
struct page *page;
swp_entry_t entry;
pte_t pte;
@@ -2255,8 +2255,6 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
}
if (!pte_present(pte)) {
- mpfn = 0;
-
/*
* Only care about unaddressable device page special
* page table entry. Other special swap entries are not
@@ -2267,11 +2265,16 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
goto next;
page = device_private_entry_to_page(entry);
+ if (page->pgmap->owner != migrate->src_owner)
+ goto next;
+
mpfn = migrate_pfn(page_to_pfn(page)) |
MIGRATE_PFN_MIGRATE;
if (is_write_device_private_entry(entry))
mpfn |= MIGRATE_PFN_WRITE;
} else {
+ if (migrate->src_owner)
+ goto next;
pfn = pte_pfn(pte);
if (is_zero_pfn(pfn)) {
mpfn = MIGRATE_PFN_MIGRATE;
--
2.24.1
