On Mon, 2021-09-20 at 12:05 +0100, Matthew Auld wrote:
> On 14/09/2021 20:31, Thomas Hellström wrote:
> > We really only need memcpy restore for objects that affect the
> > operability of the migrate context. That is, primarily the page-
> > table
> > objects of the migrate VM.
> >
> > Add an object flag, I915_BO_ALLOC_PM_EARLY for objects that need
> > early
> > restores using memcpy and a way to assign LMEM page-table object
> > flags
> > to be used by the vms.
> >
> > Restore objects without this flag with the gpu blitter and only
> > objects
> > carrying the flag using TTM memcpy.
> >
> > Initially mark the migrate, gt, gtt and vgpu vms to use this flag,
> > and
> > defer for a later audit which vms actually need it. Most
> > importantly, user-
> > allocated vms with pinned page-table objects can be restored using
> > the
> > blitter.
> >
> > Performance-wise memcpy restore is probably as fast as gpu restore
> > if not
> > faster, but using gpu restore will help tackling future
> > restrictions in
> > mappable LMEM size.
> >
> > Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 ++--
> > drivers/gpu/drm/i915/gem/i915_gem_object_types.h | 9 ++++++---
> > drivers/gpu/drm/i915/gem/i915_gem_pm.c | 5 ++++-
> > drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c | 6 ++++--
> > drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 2 +-
> > drivers/gpu/drm/i915/gt/gen6_ppgtt.c | 2 +-
> > drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 5 +++--
> > drivers/gpu/drm/i915/gt/gen8_ppgtt.h | 4 +++-
> > drivers/gpu/drm/i915/gt/intel_ggtt.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_gt.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_gtt.c | 3 ++-
> > drivers/gpu/drm/i915/gt/intel_gtt.h | 9 +++++++--
> > drivers/gpu/drm/i915/gt/intel_migrate.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_ppgtt.c | 13 ++++++++---
> > --
> > drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 2 +-
> > drivers/gpu/drm/i915/gvt/scheduler.c | 2 +-
> > drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 4 ++--
> > 17 files changed, 48 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index c2ab0e22db0a..8208fd5b72c3 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -1287,7 +1287,7 @@ i915_gem_create_context(struct
> > drm_i915_private *i915,
> > } else if (HAS_FULL_PPGTT(i915)) {
> > struct i915_ppgtt *ppgtt;
> >
> > - ppgtt = i915_ppgtt_create(&i915->gt);
> > + ppgtt = i915_ppgtt_create(&i915->gt, 0);
> > if (IS_ERR(ppgtt)) {
> > drm_dbg(&i915->drm, "PPGTT setup failed
> > (%ld)\n",
> > PTR_ERR(ppgtt));
> > @@ -1465,7 +1465,7 @@ int i915_gem_vm_create_ioctl(struct
> > drm_device *dev, void *data,
> > if (args->flags)
> > return -EINVAL;
> >
> > - ppgtt = i915_ppgtt_create(&i915->gt);
> > + ppgtt = i915_ppgtt_create(&i915->gt, 0);
> > if (IS_ERR(ppgtt))
> > return PTR_ERR(ppgtt);
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > index 118691ce81d7..fa2ba9e2a4d0 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > @@ -294,13 +294,16 @@ struct drm_i915_gem_object {
> > #define I915_BO_ALLOC_USER BIT(3)
> > /* Object is allowed to lose its contents on suspend / resume,
> > even if pinned */
> > #define I915_BO_ALLOC_PM_VOLATILE BIT(4)
> > +/* Object needs to be restored early using memcpy during resume */
> > +#define I915_BO_ALLOC_PM_EARLY BIT(5)
> > #define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS | \
> > I915_BO_ALLOC_VOLATILE | \
> > I915_BO_ALLOC_CPU_CLEAR | \
> > I915_BO_ALLOC_USER | \
> > - I915_BO_ALLOC_PM_VOLATILE)
> > -#define I915_BO_READONLY BIT(5)
> > -#define I915_TILING_QUIRK_BIT 6 /* unknown swizzling; do not
> > release! */
> > + I915_BO_ALLOC_PM_VOLATILE | \
> > + I915_BO_ALLOC_PM_EARLY)
> > +#define I915_BO_READONLY BIT(6)
> > +#define I915_TILING_QUIRK_BIT 7 /* unknown swizzling; do not
> > release! */
> >
> > /**
> > * @mem_flags - Mutable placement-related flags
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
> > index 8736ae1dfbb2..c4a75e1c12ee 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
> > @@ -98,8 +98,11 @@ int i915_gem_backup_suspend(struct
> > drm_i915_private *i915)
> > * More objects may have become unpinned as requests were
> > * retired. Now try to evict again. The gt may be wedged
> > here
> > * in which case we automatically fall back to memcpy.
> > + * We allow also backing up pinned objects that have not
> > been
> > + * marked for early recover, and that may contain, for
> > example,
> > + * page-tables for the migrate context.
> > */
> > - ret = lmem_suspend(i915, true, false);
> > + ret = lmem_suspend(i915, true, true);
>
> I guess we could have made these flags instead of bools, for better
> readability. I've already forgotten which is which :)
>
> > if (ret)
> > goto out_recover;
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
> > index a87419755d43..2684daaa2f22 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
> > @@ -57,7 +57,8 @@ static int i915_ttm_backup(struct
> > i915_gem_apply_to_region *apply,
> > if (pm_apply->allow_gpu && i915_gem_object_evictable(obj))
> > return ttm_bo_validate(bo,
> > i915_ttm_sys_placement(), &ctx);
> >
> > - if (!pm_apply->backup_pinned)
> > + if (!pm_apply->backup_pinned ||
> > + (pm_apply->allow_gpu && (obj->flags &
> > I915_BO_ALLOC_PM_EARLY)))
> > return 0;
> >
> > if (obj->flags & I915_BO_ALLOC_PM_VOLATILE)
> > @@ -156,7 +157,8 @@ static int i915_ttm_restore(struct
> > i915_gem_apply_to_region *apply,
> > if (!backup)
> > return 0;
> >
> > - if (!pm_apply->allow_gpu && (obj->flags &
> > I915_BO_ALLOC_USER))
> > + if (!pm_apply->allow_gpu && ((obj->flags &
> > I915_BO_ALLOC_USER) ||
> > + !(obj->flags &
> > I915_BO_ALLOC_PM_EARLY)))
> > return 0;
> >
> > err = i915_gem_object_lock(backup, apply->ww);
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > index 0827634c842c..77d84a9e8789 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > @@ -1645,7 +1645,7 @@ int i915_gem_huge_page_mock_selftests(void)
> > mkwrite_device_info(dev_priv)->ppgtt_type =
> > INTEL_PPGTT_FULL;
> > mkwrite_device_info(dev_priv)->ppgtt_size = 48;
> >
> > - ppgtt = i915_ppgtt_create(&dev_priv->gt);
> > + ppgtt = i915_ppgtt_create(&dev_priv->gt, 0);
> > if (IS_ERR(ppgtt)) {
> > err = PTR_ERR(ppgtt);
> > goto out_unlock;
> > diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> > b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> > index 1aee5e6b1b23..890191f286e3 100644
> > --- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> > +++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> > @@ -429,7 +429,7 @@ struct i915_ppgtt *gen6_ppgtt_create(struct
> > intel_gt *gt)
> > mutex_init(&ppgtt->flush);
> > mutex_init(&ppgtt->pin_mutex);
> >
> > - ppgtt_init(&ppgtt->base, gt);
> > + ppgtt_init(&ppgtt->base, gt, 0);
> > ppgtt->base.vm.pd_shift = ilog2(SZ_4K * SZ_4K /
> > sizeof(gen6_pte_t));
> > ppgtt->base.vm.top = 1;
> >
> > diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> > b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> > index 6a5af995f5b1..037a9a6e4889 100644
> > --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> > +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> > @@ -753,7 +753,8 @@ gen8_alloc_top_pd(struct i915_address_space
> > *vm)
> > * space.
> > *
> > */
> > -struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt)
> > +struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
> > + unsigned long
> > lmem_pt_obj_flags)
> > {
> > struct i915_ppgtt *ppgtt;
> > int err;
> > @@ -762,7 +763,7 @@ struct i915_ppgtt *gen8_ppgtt_create(struct
> > intel_gt *gt)
> > if (!ppgtt)
> > return ERR_PTR(-ENOMEM);
> >
> > - ppgtt_init(ppgtt, gt);
> > + ppgtt_init(ppgtt, gt, lmem_pt_obj_flags);
> > ppgtt->vm.top = i915_vm_is_4lvl(&ppgtt->vm) ? 3 : 2;
> > ppgtt->vm.pd_shift = ilog2(SZ_4K * SZ_4K /
> > sizeof(gen8_pte_t));
> >
> > diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> > b/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> > index b9028c2ad3c7..f541d19264b4 100644
> > --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> > +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> > @@ -12,7 +12,9 @@ struct i915_address_space;
> > struct intel_gt;
> > enum i915_cache_level;
> >
> > -struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt);
> > +struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
> > + unsigned long
> > lmem_pt_obj_flags);
> > +
> > u64 gen8_ggtt_pte_encode(dma_addr_t addr,
> > enum i915_cache_level level,
> > u32 flags);
> > diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> > b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> > index 8d71f67926f1..b99b26201b67 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> > @@ -644,7 +644,7 @@ static int init_aliasing_ppgtt(struct i915_ggtt
> > *ggtt)
> > struct i915_ppgtt *ppgtt;
> > int err;
> >
> > - ppgtt = i915_ppgtt_create(ggtt->vm.gt);
> > + ppgtt = i915_ppgtt_create(ggtt->vm.gt,
> > I915_BO_ALLOC_PM_EARLY);
>
> I guess could leave as flags=0, since appgtt is not relevant on
> discrete/modern hw(?).
>
> Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
True, I'll fix these up.
