Re: [Intel-gfx] [PATCH 7/7] drm/i915/gem: Migrate to system at dma-buf attach time (v6)

[Jason Ekstrand <jason@jlekstrand.net>]

Fixed all the nits below locally.  It'll be in the next send.

On Tue, Jul 20, 2021 at 5:53 AM Matthew Auld
<matthew.william.auld@gmail.com> wrote:
>
> On Fri, 16 Jul 2021 at 15:14, Jason Ekstrand <jason@jlekstrand.net> wrote:
> >
> > From: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> >
> > Until we support p2p dma or as a complement to that, migrate data
> > to system memory at dma-buf attach time if possible.
> >
> > v2:
> > - Rebase on dynamic exporter. Update the igt_dmabuf_import_same_driver
> >   selftest to migrate if we are LMEM capable.
> > v3:
> > - Migrate also in the pin() callback.
> > v4:
> > - Migrate in attach
> > v5: (jason)
> > - Lock around the migration
> > v6: (jason)
> > - Move the can_migrate check outside the lock
> > - Rework the selftests to test more migration conditions.  In
> >   particular, SMEM, LMEM, and LMEM+SMEM are all checked.
> >
> > Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> > Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
> > Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_create.c    |  2 +-
> >  drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    | 23 ++++-
> >  drivers/gpu/drm/i915/gem/i915_gem_object.h    |  4 +
> >  .../drm/i915/gem/selftests/i915_gem_dmabuf.c  | 89 ++++++++++++++++++-
> >  4 files changed, 112 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
> > index 039e4f3b39c79..41c4cd3e1ea01 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_create.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c
> > @@ -82,7 +82,7 @@ static int i915_gem_publish(struct drm_i915_gem_object *obj,
> >         return 0;
> >  }
> >
> > -static struct drm_i915_gem_object *
> > +struct drm_i915_gem_object *
> >  i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
> >                             struct intel_memory_region **placements,
> >                             unsigned int n_placements)
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > index 9a655f69a0671..5d438b95826b9 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > @@ -170,8 +170,29 @@ static int i915_gem_dmabuf_attach(struct dma_buf *dmabuf,
> >                                   struct dma_buf_attachment *attach)
> >  {
> >         struct drm_i915_gem_object *obj = dma_buf_to_obj(dmabuf);
> > +       struct i915_gem_ww_ctx ww;
> > +       int err;
> > +
> > +       if (!i915_gem_object_can_migrate(obj, INTEL_REGION_SMEM))
> > +               return -EOPNOTSUPP;
> > +
> > +       for_i915_gem_ww(&ww, err, true) {
> > +               err = i915_gem_object_lock(obj, &ww);
> > +               if (err)
> > +                       continue;
> > +
> > +               err = i915_gem_object_migrate(obj, &ww, INTEL_REGION_SMEM);
> > +               if (err)
> > +                       continue;
> >
> > -       return i915_gem_object_pin_pages_unlocked(obj);
> > +               err = i915_gem_object_wait_migration(obj, 0);
> > +               if (err)
> > +                       continue;
> > +
> > +               err = i915_gem_object_pin_pages(obj);
> > +       }
> > +
> > +       return err;
> >  }
> >
> >  static void i915_gem_dmabuf_detach(struct dma_buf *dmabuf,
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > index 8be4fadeee487..fbae53bd46384 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > @@ -61,6 +61,10 @@ i915_gem_object_create_shmem(struct drm_i915_private *i915,
> >  struct drm_i915_gem_object *
> >  i915_gem_object_create_shmem_from_data(struct drm_i915_private *i915,
> >                                        const void *data, resource_size_t size);
> > +struct drm_i915_gem_object *
> > +i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
> > +                           struct intel_memory_region **placements,
> > +                           unsigned int n_placements);
> >
> >  extern const struct drm_i915_gem_object_ops i915_gem_shmem_ops;
> >
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> > index 4451bbb4917e4..7b7647e7e220a 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> > @@ -85,9 +85,62 @@ static int igt_dmabuf_import_self(void *arg)
> >         return err;
> >  }
> >
> > -static int igt_dmabuf_import_same_driver(void *arg)
> > +static int igt_dmabuf_import_same_driver_lmem(void *arg)
> >  {
> >         struct drm_i915_private *i915 = arg;
> > +       struct intel_memory_region *lmem = i915->mm.regions[INTEL_REGION_LMEM];
> > +       struct drm_i915_gem_object *obj;
> > +       struct drm_gem_object *import;
> > +       struct dma_buf *dmabuf;
> > +       int err;
> > +
> > +       if (!i915->mm.regions[INTEL_REGION_LMEM])
>
> !lmem
>
> > +               return 0;
> > +
> > +       force_different_devices = true;
> > +
> > +       obj = i915_gem_object_create_user(i915, PAGE_SIZE, &lmem, 1);
> > +       if (IS_ERR(obj)) {
> > +               pr_err("i915_gem_object_create_user failed with err=%d\n",
> > +                      (int)PTR_ERR(dmabuf));
>
> PTR_ERR(obj)
>
> > +               err = PTR_ERR(obj);
> > +               goto out_ret;
> > +       }
> > +
> > +       dmabuf = i915_gem_prime_export(&obj->base, 0);
> > +       if (IS_ERR(dmabuf)) {
> > +               pr_err("i915_gem_prime_export failed with err=%d\n",
> > +                      (int)PTR_ERR(dmabuf));
> > +               err = PTR_ERR(dmabuf);
> > +               goto out;
> > +       }
> > +
> > +       /* We expect an import of an LMEM-only object to fail with
> > +        * -EOPNOTSUPP because it can't be migrated to SMEM.
> > +        */
>
> /*
>  * We expect...
>  */
>
> > +       import = i915_gem_prime_import(&i915->drm, dmabuf);
> > +       if (!IS_ERR(import)) {
> > +               drm_gem_object_put(import);
> > +               pr_err("i915_gem_prime_import succeeded when it shouldn't have\n");
> > +               err = -EINVAL;
> > +       } else if (PTR_ERR(import) != -EOPNOTSUPP) {
> > +               pr_err("i915_gem_prime_import failed with the wrong err=%d\n",
> > +                      (int)PTR_ERR(import));
> > +               err = PTR_ERR(import);
> > +       }
> > +
> > +       dma_buf_put(dmabuf);
> > +out:
> > +       i915_gem_object_put(obj);
> > +out_ret:
> > +       force_different_devices = false;
> > +       return err;
> > +}
> > +
> > +static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
> > +                                        struct intel_memory_region **regions,
> > +                                        unsigned int num_regions)
> > +{
> >         struct drm_i915_gem_object *obj, *import_obj;
> >         struct drm_gem_object *import;
> >         struct dma_buf *dmabuf;
> > @@ -97,9 +150,15 @@ static int igt_dmabuf_import_same_driver(void *arg)
> >         int err;
> >
> >         force_different_devices = true;
> > -       obj = i915_gem_object_create_shmem(i915, PAGE_SIZE);
> > -       if (IS_ERR(obj))
> > +
> > +       obj = i915_gem_object_create_user(i915, PAGE_SIZE,
> > +                                         regions, num_regions);
> > +       if (IS_ERR(obj)) {
> > +               pr_err("i915_gem_object_create_user failed with err=%d\n",
> > +                      (int)PTR_ERR(dmabuf));
>
> PTR_ERR(obj)
>
> > +               err = PTR_ERR(obj);
> >                 goto out_ret;
> > +       }
> >
> >         dmabuf = i915_gem_prime_export(&obj->base, 0);
> >         if (IS_ERR(dmabuf)) {
> > @@ -174,6 +233,26 @@ static int igt_dmabuf_import_same_driver(void *arg)
> >         return err;
> >  }
> >
> > +static int igt_dmabuf_import_same_driver_smem(void *arg)
> > +{
> > +       struct drm_i915_private *i915 = arg;
> > +       struct intel_memory_region *smem = i915->mm.regions[INTEL_REGION_SMEM];
>
> Newline.
>
> > +       return igt_dmabuf_import_same_driver(i915, &smem, 1);
> > +}
> > +
> > +static int igt_dmabuf_import_same_driver_lmem_smem(void *arg)
> > +{
> > +       struct drm_i915_private *i915 = arg;
> > +       struct intel_memory_region *regions[2];
> > +
> > +       if (!i915->mm.regions[INTEL_REGION_LMEM])
> > +               return 0;
> > +
> > +       regions[0] = i915->mm.regions[INTEL_REGION_LMEM];
> > +       regions[1] = i915->mm.regions[INTEL_REGION_SMEM];
> > +       return igt_dmabuf_import_same_driver(i915, regions, 2);
> > +}
> > +
> >  static int igt_dmabuf_import(void *arg)
> >  {
> >         struct drm_i915_private *i915 = arg;
> > @@ -384,7 +463,9 @@ int i915_gem_dmabuf_live_selftests(struct drm_i915_private *i915)
> >  {
> >         static const struct i915_subtest tests[] = {
> >                 SUBTEST(igt_dmabuf_export),
> > -               SUBTEST(igt_dmabuf_import_same_driver),
> > +               SUBTEST(igt_dmabuf_import_same_driver_lmem),
> > +               SUBTEST(igt_dmabuf_import_same_driver_smem),
> > +               SUBTEST(igt_dmabuf_import_same_driver_lmem_smem),
> >         };
> >
> >         return i915_subtests(tests, i915);
> > --
> > 2.31.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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