On Sat, Jun 25, 2022 at 8:49 PM Niranjana Vishwanathapura <
niranjana.vishwanathap...@intel.com> wrote:
> VM_BIND and related uapi definitions
>
> v2: Reduce the scope to simple Mesa use case.
> v3: Expand VM_UNBIND documentation and add
> I915_GEM_VM_BIND/UNBIND_FENCE_VALID
> and I915_GEM_VM_BIND_TLB_FLUSH flags.
> v4: Remove I915_GEM_VM_BIND_TLB_FLUSH flag and add additional
> documentation for vm_bind/unbind.
> v5: Remove TLB flush requirement on VM_UNBIND.
> Add version support to stage implementation.
> v6: Define and use drm_i915_gem_timeline_fence structure for
> all timeline fences.
> v7: Rename I915_PARAM_HAS_VM_BIND to I915_PARAM_VM_BIND_VERSION.
> Update documentation on async vm_bind/unbind and versioning.
> Remove redundant vm_bind/unbind FENCE_VALID flag, execbuf3
> batch_count field and I915_EXEC3_SECURE flag.
>
> Signed-off-by: Niranjana Vishwanathapura <
> niranjana.vishwanathap...@intel.com>
> Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
> ---
> Documentation/gpu/rfc/i915_vm_bind.h | 280 +++++++++++++++++++++++++++
> 1 file changed, 280 insertions(+)
> create mode 100644 Documentation/gpu/rfc/i915_vm_bind.h
>
> diff --git a/Documentation/gpu/rfc/i915_vm_bind.h
> b/Documentation/gpu/rfc/i915_vm_bind.h
> new file mode 100644
> index 000000000000..a93e08bceee6
> --- /dev/null
> +++ b/Documentation/gpu/rfc/i915_vm_bind.h
> @@ -0,0 +1,280 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2022 Intel Corporation
> + */
> +
> +/**
> + * DOC: I915_PARAM_VM_BIND_VERSION
> + *
> + * VM_BIND feature version supported.
> + * See typedef drm_i915_getparam_t param.
> + *
> + * Specifies the VM_BIND feature version supported.
> + * The following versions of VM_BIND have been defined:
> + *
> + * 0: No VM_BIND support.
> + *
> + * 1: In VM_UNBIND calls, the UMD must specify the exact mappings created
> + * previously with VM_BIND, the ioctl will not support unbinding
> multiple
> + * mappings or splitting them. Similarly, VM_BIND calls will not
> replace
> + * any existing mappings.
> + *
> + * 2: The restrictions on unbinding partial or multiple mappings is
> + * lifted, Similarly, binding will replace any mappings in the given
> range.
> + *
> + * See struct drm_i915_gem_vm_bind and struct drm_i915_gem_vm_unbind.
> + */
> +#define I915_PARAM_VM_BIND_VERSION 57
> +
> +/**
> + * DOC: I915_VM_CREATE_FLAGS_USE_VM_BIND
> + *
> + * Flag to opt-in for VM_BIND mode of binding during VM creation.
> + * See struct drm_i915_gem_vm_control flags.
> + *
> + * The older execbuf2 ioctl will not support VM_BIND mode of operation.
> + * For VM_BIND mode, we have new execbuf3 ioctl which will not accept any
> + * execlist (See struct drm_i915_gem_execbuffer3 for more details).
> + */
> +#define I915_VM_CREATE_FLAGS_USE_VM_BIND (1 << 0)
> +
> +/* VM_BIND related ioctls */
> +#define DRM_I915_GEM_VM_BIND 0x3d
> +#define DRM_I915_GEM_VM_UNBIND 0x3e
> +#define DRM_I915_GEM_EXECBUFFER3 0x3f
> +
> +#define DRM_IOCTL_I915_GEM_VM_BIND DRM_IOWR(DRM_COMMAND_BASE
> + DRM_I915_GEM_VM_BIND, struct drm_i915_gem_vm_bind)
> +#define DRM_IOCTL_I915_GEM_VM_UNBIND DRM_IOWR(DRM_COMMAND_BASE
> + DRM_I915_GEM_VM_UNBIND, struct drm_i915_gem_vm_bind)
> +#define DRM_IOCTL_I915_GEM_EXECBUFFER3 DRM_IOWR(DRM_COMMAND_BASE
> + DRM_I915_GEM_EXECBUFFER3, struct drm_i915_gem_execbuffer3)
> +
> +/**
> + * struct drm_i915_gem_timeline_fence - An input or output timeline fence.
> + *
> + * The operation will wait for input fence to signal.
> + *
> + * The returned output fence will be signaled after the completion of the
> + * operation.
> + */
> +struct drm_i915_gem_timeline_fence {
> + /** @handle: User's handle for a drm_syncobj to wait on or signal.
> */
> + __u32 handle;
> +
> + /**
> + * @flags: Supported flags are:
> + *
> + * I915_TIMELINE_FENCE_WAIT:
> + * Wait for the input fence before the operation.
> + *
> + * I915_TIMELINE_FENCE_SIGNAL:
> + * Return operation completion fence as output.
> + */
> + __u32 flags;
> +#define I915_TIMELINE_FENCE_WAIT (1 << 0)
> +#define I915_TIMELINE_FENCE_SIGNAL (1 << 1)
> +#define __I915_TIMELINE_FENCE_UNKNOWN_FLAGS (-(I915_TIMELINE_FENCE_SIGNAL
> << 1))
> +
> + /**
> + * @value: A point in the timeline.
> + * Value must be 0 for a binary drm_syncobj. A Value of 0 for a
> + * timeline drm_syncobj is invalid as it turns a drm_syncobj into a
> + * binary one.
> + */
> + __u64 value;
> +};
> +
> +/**
> + * struct drm_i915_gem_vm_bind - VA to object mapping to bind.
> + *
> + * This structure is passed to VM_BIND ioctl and specifies the mapping of
> GPU
> + * virtual address (VA) range to the section of an object that should be
> bound
> + * in the device page table of the specified address space (VM).
> + * The VA range specified must be unique (ie., not currently bound) and
> can
> + * be mapped to whole object or a section of the object (partial binding).
> + * Multiple VA mappings can be created to the same section of the object
> + * (aliasing).
> + *
> + * The @start, @offset and @length must be 4K page aligned. However the
> DG2
> + * and XEHPSDV has 64K page size for device local-memory and has compact
> page
> + * table. On those platforms, for binding device local-memory objects, the
> + * @start must be 2M aligned, @offset and @length must be 64K aligned.
> + * Also, for such mappings, i915 will reserve the whole 2M range for it
> so as
> + * to not allow multiple mappings in that 2M range (Compact page tables
> do not
> + * allow 64K page and 4K page bindings in the same 2M range).
> + *
> + * Error code -EINVAL will be returned if @start, @offset and @length are
> not
> + * properly aligned. In version 1 (See I915_PARAM_VM_BIND_VERSION), error
> code
> + * -ENOSPC will be returned if the VA range specified can't be reserved.
> + *
> + * VM_BIND/UNBIND ioctl calls executed on different CPU threads
> concurrently
> + * are not ordered. Furthermore, parts of the VM_BIND operation can be
> done
> + * asynchronously, if valid @fence is specified.
> + */
> +struct drm_i915_gem_vm_bind {
> + /** @vm_id: VM (address space) id to bind */
> + __u32 vm_id;
> +
> + /** @handle: Object handle */
> + __u32 handle;
> +
> + /** @start: Virtual Address start to bind */
> + __u64 start;
> +
> + /** @offset: Offset in object to bind */
> + __u64 offset;
> +
> + /** @length: Length of mapping to bind */
> + __u64 length;
> +
> + /**
> + * @flags: Supported flags are:
> + *
> + * I915_GEM_VM_BIND_READONLY:
> + * Mapping is read-only.
> + *
> + * I915_GEM_VM_BIND_CAPTURE:
> + * Capture this mapping in the dump upon GPU error.
> + */
> + __u64 flags;
> +#define I915_GEM_VM_BIND_READONLY (1 << 1)
> +#define I915_GEM_VM_BIND_CAPTURE (1 << 2)
> +
> + /**
> + * @fence: Timeline fence for bind completion signaling.
> + *
> + * It is an out fence, hence using I915_TIMELINE_FENCE_WAIT flag
> + * is invalid, and an error will be returned.
> + */
> + struct drm_i915_gem_timeline_fence fence;
>
Why a single fence and not an array of fences? If Mesa wants to use the
out fences for signalling VkSemaphores on the sparse binding queue, we need
N of them. We can still have the "zero fences means block" behavior.
--Jason
> +
> + /**
> + * @extensions: Zero-terminated chain of extensions.
> + *
> + * For future extensions. See struct i915_user_extension.
> + */
> + __u64 extensions;
> +};
> +
> +/**
> + * struct drm_i915_gem_vm_unbind - VA to object mapping to unbind.
> + *
> + * This structure is passed to VM_UNBIND ioctl and specifies the GPU
> virtual
> + * address (VA) range that should be unbound from the device page table
> of the
> + * specified address space (VM). VM_UNBIND will force unbind the specified
> + * range from device page table without waiting for any GPU job to
> complete.
> + * It is UMDs responsibility to ensure the mapping is no longer in use
> before
> + * calling VM_UNBIND.
> + *
> + * If the specified mapping is not found, the ioctl will simply return
> without
> + * any error.
> + *
> + * VM_BIND/UNBIND ioctl calls executed on different CPU threads
> concurrently
> + * are not ordered. Furthermore, parts of the VM_UNBIND operation can be
> done
> + * asynchronously, if valid @fence is specified.
> + */
> +struct drm_i915_gem_vm_unbind {
> + /** @vm_id: VM (address space) id to bind */
> + __u32 vm_id;
> +
> + /** @rsvd: Reserved, MBZ */
> + __u32 rsvd;
> +
> + /** @start: Virtual Address start to unbind */
> + __u64 start;
> +
> + /** @length: Length of mapping to unbind */
> + __u64 length;
> +
> + /** @flags: Currently reserved, MBZ */
> + __u64 flags;
> +
> + /**
> + * @fence: Timeline fence for unbind completion signaling.
> + *
> + * It is an out fence, hence using I915_TIMELINE_FENCE_WAIT flag
> + * is invalid, and an error will be returned.
> + */
> + struct drm_i915_gem_timeline_fence fence;
> +
> + /**
> + * @extensions: Zero-terminated chain of extensions.
> + *
> + * For future extensions. See struct i915_user_extension.
> + */
> + __u64 extensions;
> +};
> +
> +/**
> + * struct drm_i915_gem_execbuffer3 - Structure for
> DRM_I915_GEM_EXECBUFFER3
> + * ioctl.
> + *
> + * DRM_I915_GEM_EXECBUFFER3 ioctl only works in VM_BIND mode and VM_BIND
> mode
> + * only works with this ioctl for submission.
> + * See I915_VM_CREATE_FLAGS_USE_VM_BIND.
> + */
> +struct drm_i915_gem_execbuffer3 {
> + /**
> + * @ctx_id: Context id
> + *
> + * Only contexts with user engine map are allowed.
> + */
> + __u32 ctx_id;
> +
> + /**
> + * @engine_idx: Engine index
> + *
> + * An index in the user engine map of the context specified by
> @ctx_id.
> + */
> + __u32 engine_idx;
> +
> + /**
> + * @batch_address: Batch gpu virtual address/es.
> + *
> + * For normal submission, it is the gpu virtual address of the
> batch
> + * buffer. For parallel submission, it is a pointer to an array of
> + * batch buffer gpu virtual addresses with array size equal to the
> + * number of (parallel) engines involved in that submission (See
> + * struct i915_context_engines_parallel_submit).
> + */
> + __u64 batch_address;
> +
> + /** @flags: Currently reserved, MBZ */
> + __u64 flags;
> +
> + /** @rsvd1: Reserved, MBZ */
> + __u32 rsvd1;
> +
> + /** @fence_count: Number of fences in @timeline_fences array. */
> + __u32 fence_count;
> +
> + /**
> + * @timeline_fences: Pointer to an array of timeline fences.
> + *
> + * Timeline fences are of format struct
> drm_i915_gem_timeline_fence.
> + */
> + __u64 timeline_fences;
> +
> + /** @rsvd2: Reserved, MBZ */
> + __u64 rsvd2;
> +
> + /**
> + * @extensions: Zero-terminated chain of extensions.
> + *
> + * For future extensions. See struct i915_user_extension.
> + */
> + __u64 extensions;
> +};
> +
> +/**
> + * struct drm_i915_gem_create_ext_vm_private - Extension to make the
> object
> + * private to the specified VM.
> + *
> + * See struct drm_i915_gem_create_ext.
> + */
> +struct drm_i915_gem_create_ext_vm_private {
> +#define I915_GEM_CREATE_EXT_VM_PRIVATE 2
> + /** @base: Extension link. See struct i915_user_extension. */
> + struct i915_user_extension base;
> +
> + /** @vm_id: Id of the VM to which the object is private */
> + __u32 vm_id;
> +};
> --
> 2.21.0.rc0.32.g243a4c7e27
>
>
