On Fri, Jun 10, 2022 at 09:35:14AM -0700, Niranjana Vishwanathapura wrote:
On Fri, Jun 10, 2022 at 01:56:58AM -0700, Matthew Brost wrote:
On Fri, Jun 10, 2022 at 01:53:40AM -0700, Matthew Brost wrote:
On Fri, Jun 10, 2022 at 12:07:11AM -0700, Niranjana Vishwanathapura wrote:
VM_BIND and related uapi definitions
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathap...@intel.com>
---
Documentation/gpu/rfc/i915_vm_bind.h | 490 +++++++++++++++++++++++++++
1 file changed, 490 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..9fc854969cfb
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_vm_bind.h
@@ -0,0 +1,490 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+/**
+ * DOC: I915_PARAM_HAS_VM_BIND
+ *
+ * VM_BIND feature availability.
+ * See typedef drm_i915_getparam_t param.
+ * bit[0]: If set, VM_BIND is supported, otherwise not.
+ * bits[8-15]: VM_BIND implementation version.
+ * version 0 will not have VM_BIND/UNBIND timeline fence array support.
+ */
+#define I915_PARAM_HAS_VM_BIND 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)
+
+/**
+ * DOC: I915_CONTEXT_CREATE_FLAGS_LONG_RUNNING
+ *
+ * Flag to declare context as long running.
+ * See struct drm_i915_gem_context_create_ext flags.
+ *
+ * Usage of dma-fence expects that they complete in reasonable amount of time.
+ * Compute on the other hand can be long running. Hence it is not appropriate
+ * for compute contexts to export request completion dma-fence to user.
+ * The dma-fence usage will be limited to in-kernel consumption only.
+ * Compute contexts need to use user/memory fence.
+ *
+ * So, long running contexts do not support output fences. Hence,
+ * I915_EXEC_FENCE_SIGNAL (See &drm_i915_gem_exec_fence.flags) is expected
+ * to be not used. DRM_I915_GEM_WAIT ioctl call is also not supported for
+ * objects mapped to long running contexts.
+ */
+#define I915_CONTEXT_CREATE_FLAGS_LONG_RUNNING (1u << 2)
+
+/* 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_I915_GEM_WAIT_USER_FENCE 0x40
+
+#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)
+#define DRM_IOCTL_I915_GEM_WAIT_USER_FENCE DRM_IOWR(DRM_COMMAND_BASE +
DRM_I915_GEM_WAIT_USER_FENCE, struct drm_i915_gem_wait_user_fence)
+
+/**
+ * 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 @queue_idx specifies the queue to use for binding. Same queue can be
+ * used for both VM_BIND and VM_UNBIND calls. All submitted bind and unbind
+ * operations in a queue are performed in the order of submission.
+ *
+ * The @start, @offset and @length should 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 should be 2M aligned, @offset and @length should be 64K aligned.
+ * Also, on those platforms, it is not allowed to bind an device local-memory
+ * object and a system memory object in a single 2M section of VA range.
+ */
+struct drm_i915_gem_vm_bind {
+ /** @vm_id: VM (address space) id to bind */
+ __u32 vm_id;
+
+ /** @queue_idx: Index of queue for binding */
+ __u32 queue_idx;
+
+ /** @rsvd: Reserved, MBZ */
+ __u32 rsvd;
+
+ /** @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;
This probably isn't needed. We are never going to unbind a subset of a
VMA are we? That being said it can't hurt as a sanity check (e.g.
internal vma->length == user unbind length).
Ugh, I c/p this into the wrong place. This should be in the unbind struct.
Having the 'length' field for unbind helps if in future we want to allow
unbinding of multiple mappings (vmas) in a single ioctl call. ie., all
mappings that falls in the 'start' - 'start+length-1' range can be
unmapped. We don't support it today as it is somewhat tied to operations
like vma split/merge etc which we are not supporting with initial vm_bind
support.
So yah, currently, it helps in sanity check and ensure user is correctly
unbinding a mapping.
+
+ /**
+ * @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 << 0)
+#define I915_GEM_VM_BIND_CAPTURE (1 << 1)
+
+ /**
+ * @extensions: 0-terminated chain of extensions for this operation.
+ *
+ * I915_VM_BIND_EXT_TIMELINE_FENCES:
+ * Specifies an array of input or output timeline fences for this
+ * binding operation. See struct drm_i915_vm_bind_ext_timeline_fences.
+ *
+ * I915_VM_BIND_EXT_USER_FENCES:
+ * Specifies an array of input or output user fences for this
+ * binding operation. See struct drm_i915_vm_bind_ext_user_fence.
+ * This is required for compute contexts.
+ */
+ __u64 extensions;
+#define I915_VM_BIND_EXT_TIMELINE_FENCES 0
+#define I915_VM_BIND_EXT_USER_FENCES 1
+};
+
+/**
+ * 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). The specified VA range must match one of the
+ * mappings created with the VM_BIND ioctl. TLB is flushed upon unbind
+ * completion.
+ *
+ * The @queue_idx specifies the queue to use for unbinding.
+ * See struct drm_i915_gem_vm_unbind for more information on @queue_idx.
+ *
+ * The @start and @length musy specify a unique mapping bound with VM_BIND
+ * ioctl.
+ */
+struct drm_i915_gem_vm_unbind {
+ /** @vm_id: VM (address space) id to bind */
+ __u32 vm_id;
+
+ /** @queue_idx: Index of queue for unbinding */
+ __u32 queue_idx;
+
+ /** @start: Virtual Address start to unbind */
+ __u64 start;
+
+ /** @length: Length of mapping to unbind */
+ __u64 length;
+
+ /** @flags: Reserved for future usage, currently MBZ */
+ __u64 flags;
+
+ /**
+ * @extensions: 0-terminated chain of extensions for this operation.
+ *
+ * I915_VM_UNBIND_EXT_TIMELINE_FENCES:
+ * Specifies an array of input or output timeline fences for this
+ * unbind operation.
+ * It has same format as struct drm_i915_vm_bind_ext_timeline_fences.
+ *
+ * I915_VM_UNBIND_EXT_USER_FENCES:
+ * Specifies an array of input or output user fences for this
+ * unbind operation. This is required for compute contexts.
+ * It has same format as struct drm_i915_vm_bind_ext_user_fence.
+ */
+ __u64 extensions;
+#define I915_VM_UNBIND_EXT_TIMELINE_FENCES 0
+#define I915_VM_UNBIND_EXT_USER_FENCES 1
+};
+
+/**
+ * struct drm_i915_vm_bind_fence - An input or output fence for the vm_bind
+ * or the vm_unbind work.
+ *
+ * The vm_bind or vm_unbind aync worker will wait for input fence to signal
+ * before starting the binding or unbinding.
+ *
+ * The vm_bind or vm_unbind async worker will signal the returned output fence
+ * after the completion of binding or unbinding.
+ */
+struct drm_i915_vm_bind_fence {
+ /** @handle: User's handle for a drm_syncobj to wait on or signal. */
+ __u32 handle;
+
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_VM_BIND_FENCE_WAIT:
+ * Wait for the input fence before binding/unbinding
+ *
+ * I915_VM_BIND_FENCE_SIGNAL:
+ * Return bind/unbind completion fence as output
+ */
+ __u32 flags;
+#define I915_VM_BIND_FENCE_WAIT (1<<0)
+#define I915_VM_BIND_FENCE_SIGNAL (1<<1)
+#define __I915_VM_BIND_FENCE_UNKNOWN_FLAGS (-(I915_VM_BIND_FENCE_SIGNAL << 1))
+};
+
+/**
+ * struct drm_i915_vm_bind_ext_timeline_fences - Timeline fences for vm_bind
+ * and vm_unbind.
+ *
+ * This structure describes an array of timeline drm_syncobj and associated
+ * points for timeline variants of drm_syncobj. These timeline 'drm_syncobj's
+ * can be input or output fences (See struct drm_i915_vm_bind_fence).
+ */
+struct drm_i915_vm_bind_ext_timeline_fences {
+ /** @base: Extension link. See struct i915_user_extension. */
+ struct i915_user_extension base;
+
+ /**
+ * @fence_count: Number of elements in the @handles_ptr & @value_ptr
+ * arrays.
+ */
+ __u64 fence_count;
+
+ /**
+ * @handles_ptr: Pointer to an array of struct drm_i915_vm_bind_fence
+ * of length @fence_count.
+ */
+ __u64 handles_ptr;
+
+ /**
+ * @values_ptr: Pointer to an array of u64 values of length
+ * @fence_count.
+ * Values 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 values_ptr;
+};
+
+/**
+ * struct drm_i915_vm_bind_user_fence - An input or output user fence for the
+ * vm_bind or the vm_unbind work.
+ *
+ * The vm_bind or vm_unbind aync worker will wait for the input fence (value at
+ * @addr to become equal to @val) before starting the binding or unbinding.
+ *
+ * The vm_bind or vm_unbind async worker will signal the output fence after
+ * the completion of binding or unbinding by writing @val to memory location at
+ * @addr
+ */
+struct drm_i915_vm_bind_user_fence {
+ /** @addr: User/Memory fence qword aligned process virtual address */
+ __u64 addr;
+
+ /** @val: User/Memory fence value to be written after bind completion */
+ __u64 val;
+
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_VM_BIND_USER_FENCE_WAIT:
+ * Wait for the input fence before binding/unbinding
+ *
+ * I915_VM_BIND_USER_FENCE_SIGNAL:
+ * Return bind/unbind completion fence as output
+ */
+ __u32 flags;
+#define I915_VM_BIND_USER_FENCE_WAIT (1<<0)
+#define I915_VM_BIND_USER_FENCE_SIGNAL (1<<1)
+#define __I915_VM_BIND_USER_FENCE_UNKNOWN_FLAGS \
+ (-(I915_VM_BIND_USER_FENCE_SIGNAL << 1))
+};
+
+/**
+ * struct drm_i915_vm_bind_ext_user_fence - User/memory fences for vm_bind
+ * and vm_unbind.
+ *
+ * These user fences can be input or output fences
+ * (See struct drm_i915_vm_bind_user_fence).
+ */
+struct drm_i915_vm_bind_ext_user_fence {
+ /** @base: Extension link. See struct i915_user_extension. */
+ struct i915_user_extension base;
+
+ /** @fence_count: Number of elements in the @user_fence_ptr array. */
+ __u64 fence_count;
+
+ /**
+ * @user_fence_ptr: Pointer to an array of
+ * struct drm_i915_vm_bind_user_fence of length @fence_count.
+ */
+ __u64 user_fence_ptr;
+};
+
+/**
+ * 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;
+
+ /** @rsvd1: Reserved, MBZ */
+ __u32 rsvd1;
+
+ /**
+ * @batch_count: Number of batches in @batch_address array.
+ *
+ * 0 is invalid. For parallel submission, it should be equal to the
+ * number of (parallel) engines involved in that submission.
+ */
+ __u32 batch_count;
+
+ /**
+ * @batch_address: Array of batch gpu virtual addresses.
+ *
+ * If @batch_count is 1, then it is the gpu virtual address of the
+ * batch buffer. If @batch_count > 1, then it is a pointer to an array
+ * of batch buffer gpu virtual addresses.
+ */
+ __u64 batch_address;
+
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_EXEC3_SECURE:
+ * Request a privileged ("secure") batch buffer/s.
+ * It is only available for DRM_ROOT_ONLY | DRM_MASTER processes.
+ */
+ __u64 flags;
+#define I915_EXEC3_SECURE (1<<0)
+
+ /** @rsvd2: Reserved, MBZ */
+ __u64 rsvd2;
+
+ /**
+ * @extensions: Zero-terminated chain of extensions.
+ *
+ * DRM_I915_GEM_EXECBUFFER3_EXT_TIMELINE_FENCES:
+ * It has same format as DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES.
+ * See struct drm_i915_gem_execbuffer_ext_timeline_fences.
+ *
+ * DRM_I915_GEM_EXECBUFFER3_EXT_USER_FENCE:
+ * First level batch completion signaling extension.
+ * See struct drm_i915_gem_execbuffer3_ext_user_fence.
+ */
+ __u64 extensions;
+#define DRM_I915_GEM_EXECBUFFER3_EXT_TIMELINE_FENCES 0
+#define DRM_I915_GEM_EXECBUFFER3_EXT_USER_FENCE 1
+};
+
+/**
+ * struct drm_i915_gem_execbuffer3_ext_user_fence - First level batch
completion
+ * signaling extension.
+ *
+ * This extension allows user to attach a user fence (@addr, @value pair) to
+ * execbuf3, to be signaled by the command streamer after the completion of
first
+ * level batch, by writing the @value at specified @addr and triggering an
+ * interrupt.
+ * User can either poll for this user fence to signal or can also wait on it
+ * with i915_gem_wait_user_fence ioctl.
+ * This is very much usefaul for long running contexts where waiting on
dma-fence
+ * by user (like i915_gem_wait ioctl) is not supported.
+ */
+struct drm_i915_gem_execbuffer3_ext_user_fence {
+ /** @base: Extension link. See struct i915_user_extension. */
+ struct i915_user_extension base;
+
+ /**
+ * @addr: User/Memory fence qword aligned GPU virtual address.
+ *
+ * Address has to be a valid GPU virtual address at the time of
+ * first level batch completion.
+ */
+ __u64 addr;
+
+ /**
+ * @value: User/Memory fence Value to be written to above address
+ * after first level batch completes.
+ */
+ __u64 value;
+
+ /** @rsvd: Reserved, MBZ */
+ __u64 rsvd;
+};
+
IMO all of these fence structs should be a generic sync interface shared
between both vm bind and exec3 rather than unique extenisons.
Both vm bind and exec3 should have something like this:
__64 syncs; /* userptr to an array of generic syncs */
__64 n_syncs;
Having an array of syncs lets the kernel do one user copy for all the
syncs rather than reading them in a a chain.
A generic sync object encapsulates all possible syncs (in / out -
syncobj, syncobj timeline, ufence, future sync concepts).
e.g.
struct {
__u32 user_ext;
__u32 flag; /* in / out, type, whatever else info we need */
union {
__u32 handle; /* to syncobj */
__u64 addr; /* ufence address */
};
__64 seqno; /* syncobj timeline, ufence write value */
...reserve enough bits for future...
}
This unifies binds and execs by using the same sync interface
instilling the concept that binds and execs are the same op (queue'd
operation /w in/out fences).
Hmm...I am not sure whether we really need to merge all fence types
together in a single structure.
Yes, timeline fence array struct is same between vm_bind and execbuf.
But user fence array is not. For compute use case, VM_BIND/UNBIND can
have user fence array. But execbuf will only have one user fence as
out fence. Execbuf can have timeline fence array as 'in' fences for
compute use case.
Besides, for VM_BIND/UNBIND, user will use either the timeline fence
array (mesa) or the user fence array (compute) and will never mix
them (ie., having some fences as timeline fences and some as user
fences is not allowed). Hence, no multiple copy_from_user concern.
So, not sure if having a generic fence is a good idea. It will be
also less confusing for the user if we define them separately.
But internally i915 can maintain them in a generic sturcture if needed.
Also, I don't think we will have a case where an array of fences
passed by user will have a mix of timeline and user fences.
So, we don't need a 'type' in each element of the array. The
extension (timeline or user fence) will be the type.
Niranjana
Niranjana
Matt
+/**
+ * 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;
+};
+
+/**
+ * struct drm_i915_gem_wait_user_fence - Wait on user/memory fence.
+ *
+ * User/Memory fence can be woken up either by:
+ *
+ * 1. GPU context indicated by @ctx_id, or,
+ * 2. Kerrnel driver async worker upon I915_UFENCE_WAIT_SOFT.
+ * @ctx_id is ignored when this flag is set.
+ *
+ * Wakeup condition is,
+ * ``((*addr & mask) op (value & mask))``
+ *
+ * See :ref:`Documentation/driver-api/dma-buf.rst <indefinite_dma_fences>`
+ */
+struct drm_i915_gem_wait_user_fence {
+ /** @extensions: Zero-terminated chain of extensions. */
+ __u64 extensions;
+
+ /** @addr: User/Memory fence address */
+ __u64 addr;
+
+ /** @ctx_id: Id of the Context which will signal the fence. */
+ __u32 ctx_id;
+
+ /** @op: Wakeup condition operator */
+ __u16 op;
+#define I915_UFENCE_WAIT_EQ 0
+#define I915_UFENCE_WAIT_NEQ 1
+#define I915_UFENCE_WAIT_GT 2
+#define I915_UFENCE_WAIT_GTE 3
+#define I915_UFENCE_WAIT_LT 4
+#define I915_UFENCE_WAIT_LTE 5
+#define I915_UFENCE_WAIT_BEFORE 6
+#define I915_UFENCE_WAIT_AFTER 7
+
+ /**
+ * @flags: Supported flags are:
+ *
+ * I915_UFENCE_WAIT_SOFT:
+ *
+ * To be woken up by i915 driver async worker (not by GPU).
+ *
+ * I915_UFENCE_WAIT_ABSTIME:
+ *
+ * Wait timeout specified as absolute time.
+ */
+ __u16 flags;
+#define I915_UFENCE_WAIT_SOFT 0x1
+#define I915_UFENCE_WAIT_ABSTIME 0x2
+
+ /** @value: Wakeup value */
+ __u64 value;
+
+ /** @mask: Wakeup mask */
+ __u64 mask;
+#define I915_UFENCE_WAIT_U8 0xffu
+#define I915_UFENCE_WAIT_U16 0xffffu
+#define I915_UFENCE_WAIT_U32 0xfffffffful
+#define I915_UFENCE_WAIT_U64 0xffffffffffffffffull
+
+ /**
+ * @timeout: Wait timeout in nanoseconds.
+ *
+ * If I915_UFENCE_WAIT_ABSTIME flag is set, then time timeout is the
+ * absolute time in nsec.
+ */
+ __s64 timeout;
+};
--
2.21.0.rc0.32.g243a4c7e27
