Commit 5143192c authored by Ralph Campbell's avatar Ralph Campbell Committed by Jason Gunthorpe
Browse files

mm/migrate: add a flags parameter to migrate_vma 

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: default avatarRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: default avatarBharata B Rao <bharata@linux.ibm.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 1a77decd

arch/powerpc/kvm/book3s_hv_uvmem.c

+3 −1
Original line number Diff line number Diff line
@@ -400,6 +400,7 @@ kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, 
	mig.end = end;

	mig.src = &src_pfn;

	mig.dst = &dst_pfn;

	mig.flags = MIGRATE_VMA_SELECT_SYSTEM;



	/*

	 * We come here with mmap_lock write lock held just for
@@ -577,7 +578,8 @@ 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;

	mig.pgmap_owner = &kvmppc_uvmem_pgmap;

	mig.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;



	mutex_lock(&kvm->arch.uvmem_lock);

	/* The requested page is already paged-out, nothing to do */

drivers/gpu/drm/nouveau/nouveau_dmem.c

+3 −1
Original line number Diff line number Diff line
@@ -182,7 +182,8 @@ 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,

		.pgmap_owner	= drm->dev,

		.flags		= MIGRATE_VMA_SELECT_DEVICE_PRIVATE,

	};



	/*
@@ -615,6 +616,7 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, 
	struct migrate_vma args = {

		.vma		= vma,

		.start		= start,

		.flags		= MIGRATE_VMA_SELECT_SYSTEM,

	};

	unsigned long i;

	u64 *pfns;

include/linux/migrate.h

+9 −4
Original line number Diff line number Diff line
@@ -180,6 +180,11 @@ static inline unsigned long migrate_pfn(unsigned long 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);

lib/test_hmm.c

+4 −11
Original line number Diff line number Diff line
@@ -585,15 +585,6 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, 
		 */

		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 dmirror *dmirror, 
		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(struct vm_fault *vmf) 
	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;

mm/migrate.c

+4 −2
Original line number Diff line number Diff line
@@ -2287,7 +2287,9 @@ 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)) |
@@ -2295,7 +2297,7 @@ 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)) {

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