A usecase arose out of handling context recovery in mesa, whereby they wish to recreate a context with fresh logical state but preserving all other details of the original. Currently, they create a new context and iterate over which bits they want to copy across, but it would much more convenient if they were able to just pass in a target context to clone during creation. This essentially extends the setparam during creation to pull the details from a target context instead of the user supplied parameters.
Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/i915_gem_context.c | 103 ++++++++++++++++++++++++ include/uapi/drm/i915_drm.h | 14 ++++ 2 files changed, 117 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 4e4b0b5c4be0..bac548584091 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -1488,8 +1488,111 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data) return ctx_setparam(data, &local.setparam); } +static int clone_sseu(struct i915_gem_context *dst, + struct i915_gem_context *src) +{ + const struct intel_sseu default_sseu = + intel_device_default_sseu(dst->i915); + struct intel_engine_cs *engine; + enum intel_engine_id id; + + for_each_engine(engine, dst->i915, id) { + struct intel_context *ce; + struct intel_sseu sseu; + + ce = intel_context_lookup(src, engine); + if (!ce) + continue; + + sseu = ce->sseu; + if (!memcmp(&sseu, &default_sseu, sizeof(sseu))) + continue; + + ce = intel_context_pin_lock(dst, engine); + if (IS_ERR(ce)) + return PTR_ERR(ce); + + ce->sseu = sseu; + intel_context_pin_unlock(ce); + } + + return 0; +} + +static int create_clone(struct i915_user_extension __user *ext, void *data) +{ + struct drm_i915_gem_context_create_ext_clone local; + struct i915_gem_context *dst = data; + struct i915_gem_context *src; + int err; + + if (copy_from_user(&local, ext, sizeof(local))) + return -EFAULT; + + if (local.flags & I915_CONTEXT_CLONE_UNKNOWN) + return -EINVAL; + + if (local.rsvd) + return -EINVAL; + + if (local.clone_id == dst->user_handle) /* good guess! denied. */ + return -ENOENT; + + rcu_read_lock(); + src = __i915_gem_context_lookup_rcu(dst->file_priv, local.clone_id); + rcu_read_unlock(); + if (!src) + return -ENOENT; + + GEM_BUG_ON(src == dst); + + if (local.flags & I915_CONTEXT_CLONE_FLAGS) + dst->user_flags = src->user_flags; + + if (local.flags & I915_CONTEXT_CLONE_SCHED) + dst->sched = src->sched; + + if (local.flags & I915_CONTEXT_CLONE_SSEU) { + err = clone_sseu(dst, src); + if (err) + return err; + } + + if (local.flags & I915_CONTEXT_CLONE_TIMELINE && src->timeline) { + if (dst->timeline) + i915_timeline_put(dst->timeline); + dst->timeline = i915_timeline_get(src->timeline); + } + + if (local.flags & I915_CONTEXT_CLONE_VM) { + struct i915_hw_ppgtt *ppgtt; + + do { + ppgtt = READ_ONCE(src->ppgtt); + if (!ppgtt) + break; + + if (!kref_get_unless_zero(&ppgtt->ref)) + continue; + + if (ppgtt == READ_ONCE(src->ppgtt)) + break; + + i915_ppgtt_put(ppgtt); + } while (1); + + if (ppgtt) { + __assign_ppgtt(dst, ppgtt); + i915_ppgtt_put(ppgtt); + } + } + + return 0; +} + static const i915_user_extension_fn create_extensions[] = { [I915_CONTEXT_CREATE_EXT_SETPARAM] = create_setparam, + [I915_CONTEXT_CREATE_EXT_CLONE] = create_clone, }; static bool client_is_banned(struct drm_i915_file_private *file_priv) diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 5206d0006043..9714520f43da 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -1581,6 +1581,20 @@ struct drm_i915_gem_context_create_ext_setparam { struct drm_i915_gem_context_param setparam; }; +struct drm_i915_gem_context_create_ext_clone { +#define I915_CONTEXT_CREATE_EXT_CLONE 1 + struct i915_user_extension base; + __u32 clone_id; + __u32 flags; +#define I915_CONTEXT_CLONE_FLAGS (1u << 0) +#define I915_CONTEXT_CLONE_SCHED (1u << 1) +#define I915_CONTEXT_CLONE_SSEU (1u << 2) +#define I915_CONTEXT_CLONE_TIMELINE (1u << 3) +#define I915_CONTEXT_CLONE_VM (1u << 4) +#define I915_CONTEXT_CLONE_UNKNOWN -(I915_CONTEXT_CLONE_VM << 1) + __u64 rsvd; +}; + struct drm_i915_gem_context_destroy { __u32 ctx_id; __u32 pad; -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
