On Mon, Jul 13, 2020 at 10:21:46AM -0700, Ralph Campbell wrote:
> The src_owner field in struct migrate_vma is being used for two purposes,
> it implies the direction of the migration 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().
>
> Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> Reviewed-by: Bharata B Rao <bharata@xxxxxxxxxxxxx>
> arch/powerpc/kvm/book3s_hv_uvmem.c | 2 ++
> drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 ++
> include/linux/migrate.h | 12 +++++++++---
> lib/test_hmm.c | 2 ++
> mm/migrate.c | 5 +++--
> 5 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
> index 09d8119024db..acbf14cd2d72 100644
> +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
> @@ -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.dir = MIGRATE_VMA_FROM_SYSTEM;
>
> /*
> * We come here with mmap_lock write lock held just for
> @@ -578,6 +579,7 @@ kvmppc_svm_page_out(struct vm_area_struct *vma, unsigned long start,
> mig.src = &src_pfn;
> mig.dst = &dst_pfn;
> mig.src_owner = &kvmppc_uvmem_pgmap;
> + mig.dir = MIGRATE_VMA_FROM_DEVICE_PRIVATE;
>
> 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 e5c230d9ae24..e5c83b8ee82e 100644
> +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> @@ -183,6 +183,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
> .src = &src,
> .dst = &dst,
> .src_owner = drm->dev,
> + .dir = MIGRATE_VMA_FROM_DEVICE_PRIVATE,
> };
>
> /*
> @@ -615,6 +616,7 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
> struct migrate_vma args = {
> .vma = vma,
> .start = start,
> + .dir = MIGRATE_VMA_FROM_SYSTEM,
> };
> unsigned long i;
> u64 *pfns;
> diff --git a/include/linux/migrate.h b/include/linux/migrate.h
> index 3e546cbf03dd..620f2235d7d4 100644
> +++ b/include/linux/migrate.h
> @@ -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_FROM_SYSTEM,
> + MIGRATE_VMA_FROM_DEVICE_PRIVATE,
> +};
I would have guessed this is more natural as _FROM_DEVICE_ and
TO_DEVICE_ ?
All the callers of this API are device drivers managing their
DEVICE_PRIVATE, right?
Jason
