[i-g-t v2 2/4] lib/xe/xe_util: Introduce helper functions
Zbigniew Kempczyński
zbigniew.kempczynski at intel.com
Thu Feb 20 05:41:03 UTC 2025
On Tue, Feb 18, 2025 at 05:38:57PM +0100, Zeng, Oak wrote:
> Hi Zbigniew,
>
> > -----Original Message-----
> > From: Kempczynski, Zbigniew <zbigniew.kempczynski at intel.com>
> > Sent: February 18, 2025 1:59 AM
> > To: Zeng, Oak <oak.zeng at intel.com>
> > Cc: igt-dev at lists.freedesktop.org; Thomas.Hellstrom at linux.intel.com;
> > Brost, Matthew <matthew.brost at intel.com>; Konieczny, Kamil
> > <kamil.konieczny at intel.com>; Dixit, Ashutosh
> > <ashutosh.dixit at intel.com>; Heikkila, Juha-pekka <juha-
> > pekka.heikkila at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
> > Subject: Re: [i-g-t v2 2/4] lib/xe/xe_util: Introduce helper functions
> >
> > On Fri, Feb 14, 2025 at 04:59:18PM -0500, Oak Zeng wrote:
> > > From: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
> > >
> > > Introduce helper functions for buffer creation, binding,
> > > destruction and command submission etc. With those helpers,
> > > writing a xe igt test will be much easier, which will be
> > > showed in a coming example.
> > >
> > > v2: use to_user_pointer to cast a pointer (Kamil)
> > > s/insert_store/xe_insert_store (Kamil)
> > > s/cmdbuf_fill_func_t/xe_cmdbuf_fill_func_t (Kamil)
> > >
> > > Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
> > > Signed-off-by: Oak Zeng <oak.zeng at intel.com>
> > > Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> > > ---
> > > lib/xe/xe_util.c | 201
> > +++++++++++++++++++++++++++++++++++++++++++++++
> > > lib/xe/xe_util.h | 33 ++++++++
> > > 2 files changed, 234 insertions(+)
> > >
> > > diff --git a/lib/xe/xe_util.c b/lib/xe/xe_util.c
> > > index 06b378ce0..fcb904ce7 100644
> > > --- a/lib/xe/xe_util.c
> > > +++ b/lib/xe/xe_util.c
> > > @@ -13,6 +13,207 @@
> > > #include "xe/xe_query.h"
> > > #include "xe/xe_util.h"
> > >
> > > +/**
> > > + * __xe_submit_cmd:
> > > + * @cmdbuf Pointer to the command buffer structure
> > > + *
> > > + * Submits a command buffer to the GPU, waits for its completion,
> > and verifies
> > > + * the user fence value
> > > + *
> > > + * Return: The result of waiting for the user fence value
> > > + */
> > > +int64_t __xe_submit_cmd(struct xe_buffer *cmdbuf)
> > > +{
> > > + int64_t timeout = NSEC_PER_SEC;
> > > + int ret;
> > > +
> > > + struct drm_xe_sync sync[1] = {
> > > + { .type = DRM_XE_SYNC_TYPE_USER_FENCE,
> > > + .flags = DRM_XE_SYNC_FLAG_SIGNAL,
> > > + .timeline_value = USER_FENCE_VALUE,
> > > + .addr =
> > xe_cmdbuf_exec_ufence_gpuva(cmdbuf),},
> > > + };
> > > + struct drm_xe_exec exec = {
> > > + .num_batch_buffer = 1,
> > > + .num_syncs = 1,
> > > + .syncs = to_user_pointer(&sync),
> > > + .exec_queue_id = cmdbuf->exec_queue,
> > > + .address = cmdbuf->gpu_addr,
> > > + };
> > > +
> > > + xe_exec(cmdbuf->fd, &exec);
> > > + ret = __xe_wait_ufence(cmdbuf->fd,
> > xe_cmdbuf_exec_ufence_cpuva(cmdbuf),
> > > + USER_FENCE_VALUE, cmdbuf-
> > >exec_queue, &timeout);
> > > + /* Reset the fence so next fence wait won't return
> > immediately */
> > > + memset(xe_cmdbuf_exec_ufence_cpuva(cmdbuf), 0,
> > UFENCE_LENGTH);
> > > + return ret;
> > > +}
> > > +
> > > +/**
> > > + * xe_submit_cmd:
> > > + * @cmdbuf Pointer to the command buffer structure
> > > + *
> > > + * Wrapper function to submit a command buffer and assert its
> > successful
> > > + * execution.
> > > + */
> > > +void xe_submit_cmd(struct xe_buffer *cmdbuf)
> > > +{
> > > + int64_t ret;
> > > +
> > > + ret = __xe_submit_cmd(cmdbuf);
> > > + igt_assert_eq(ret, 0);
> > > +}
> > > +
> > > +/**
> > > + *xe_create_buffer:
> > > + * @buffer Pointer to the xe_buffer structure containing buffer
> > details.
> > > + *
> > > + * Creates a buffer, maps it to both CPU and GPU address spaces,
> > and binds it
> > > + * to a virtual memory (VM) space.
> > > + */
> > > +void xe_create_buffer(struct xe_buffer *buffer)
> > > +{
> > > + struct drm_xe_sync sync[1] = {
> > > + { .type = DRM_XE_SYNC_TYPE_USER_FENCE,
> > > + .flags = DRM_XE_SYNC_FLAG_SIGNAL,
> > > + .timeline_value = USER_FENCE_VALUE },
> > > + };
> > > +
> > > + buffer->bind_queue = xe_bind_exec_queue_create(buffer-
> > >fd,
> > > + buffer->vm, 0);
> > > + buffer->bind_ufence =
> > aligned_alloc(xe_get_default_alignment(buffer->fd),
> > > + PAGE_ALIGN_UFENCE);
> > > + sync->addr = to_user_pointer(buffer->bind_ufence);
> > > +
> > > +
> > > + /* create and bind the buffer->bo */
> > > + buffer->bo = xe_bo_create(buffer->fd, 0, buffer->size,
> > > + buffer->placement, buffer->flag);
> > > + buffer->cpu_addr = xe_bo_map(buffer->fd, buffer->bo,
> > buffer->size);
> > > + xe_vm_bind_async(buffer->fd, buffer->vm, buffer-
> > >bind_queue,
> > > + buffer->bo, 0, buffer->gpu_addr,
> > > + buffer->size, sync, 1);
> > > +
> > > + xe_wait_ufence(buffer->fd, buffer->bind_ufence,
> > > + USER_FENCE_VALUE, buffer->bind_queue,
> > NSEC_PER_SEC);
> > > + memset(buffer->bind_ufence, 0, PAGE_ALIGN_UFENCE);
> > > +}
> > > +
> > > +/**
> > > + * xe_destroy_buffer:
> > > + * @buffer Pointer to the xe_buffer structure containing buffer
> > details
> > > + *
> > > + * Destroys a buffer created by xe_create_buffer and releases
> > associated
> > > + * resources.
> > > + */
> > > +void xe_destroy_buffer(struct xe_buffer *buffer)
> > > +{
> > > + struct drm_xe_sync sync[1] = {
> > > + { .type = DRM_XE_SYNC_TYPE_USER_FENCE,
> > > + .flags = DRM_XE_SYNC_FLAG_SIGNAL,
> > > + .timeline_value = USER_FENCE_VALUE },
> > > + };
> > > + sync->addr = to_user_pointer(buffer->bind_ufence);
> > > +
> > > + xe_vm_unbind_async(buffer->fd, buffer->vm, buffer-
> > >bind_queue,
> > > + 0, buffer->gpu_addr, buffer->size, sync, 1);
> > > + xe_wait_ufence(buffer->fd, buffer->bind_ufence,
> > > + USER_FENCE_VALUE, buffer->bind_queue,
> > NSEC_PER_SEC);
> > > + memset(buffer->bind_ufence, 0, PAGE_ALIGN_UFENCE);
> > > +
> > > + munmap(buffer->cpu_addr, buffer->size);
> > > + gem_close(buffer->fd, buffer->bo);
> > > +
> > > + free(buffer->bind_ufence);
> > > + xe_exec_queue_destroy(buffer->fd, buffer->bind_queue);
> > > +}
> > > +
> > > +/**
> > > + * xe_insert_store:
> > > + * @batch Pointer to the batch buffer where commands will be
> > inserted.
> > > + * @dst_va Destination virtual address to store the value.
> > > + * @val Value to be stored.
> > > + *
> > > + * Inserts a MI_STORE_DWORD_IMM_GEN4 command into a
> > batch buffer, which stores
> > > + * an immediate value to a given destination virtual address.
> > > + */
> > > +void xe_insert_store(uint32_t *batch, uint64_t dst_va, uint32_t
> > val)
> > > +{
> > > + int i = 0;
> > > +
> > > + batch[i] = MI_STORE_DWORD_IMM_GEN4;
> > > + batch[++i] = dst_va;
> > > + batch[++i] = dst_va >> 32;
> > > + batch[++i] = val;
> > > + batch[++i] = MI_BATCH_BUFFER_END;
> >
> > What BBE is doing here? Function name is confusing, you can't
> > glued this with something else. I would suggest to at least
> > return index of last written dword, to allow adding other
> > commands to same batch (I mean passing &batch[last_index]
> > to other functions).
>
> Good point. I agree the interface should allow appending multiple
> Commands to one batch buffer. It will make this library more flexible.
> Here is what I plan to do:
>
> 1) remove the BBE from above xe_insert_store function. This basically
> Leave the command buffer open to add more command
> 2) introduce a new class xe_cmd_buffer, inherit from xe_buffer. Xe_cmd_buffer
> Has a private member to store the last_index. Obviously last_index doesn't belong
> To xe_buffer. Plus xec_queue also doesn't belong to xe_buffer, only belong to
> Xe_cmd_buffer. This give us enough reason to create new xe_cmd_buffer class.
> 3) reparameter/repurpose the xe_create_cmdbuf function: only create buffer and
> Initialize class members, but not fill commands to command buffer yet.
> 4) introduce separate interface to stuff commands to command buffer
> 5) introduce separate interface to close command buffer by add a BBE command
> To the end of command buffer.
>
> With this refactor, we do requires extra codes in writing a test. With the current
> Interface, we can create and fill command buffer calling one API. With above refactor
> We would need call 3 APIs (create_cmd_buffer, fill_cmd_buffer, close_cmd_buffer).
> But the new approach does look more flexible.
>
> I will implement above. Please let me know whether this is a ideal plan for you.
+Matt Brost
Be aware this is second time these helpers come to igt. First time
Matt wasn't happy because handcrafting everything gives him more
control. I have no strong preference, for me if this is useful
for writing tests it's fine. Especially if this will simplify the
code. From the other hand we already have intel-bb, which allows
you to create batch buffer and fill it with commands (it was made
as a replacement for previously used libdrm and its widely used
in rendercopy/gpgpu fill/other tests - it supports both drivers
- i915 and xe). So before you'll decide to send this please check
if your test can use already existing infrastructure.
--
Zbigniew
>
> Thanks for the review Zbigniew!
>
> Oak
>
> >
> > --
> > Zbigniew
> >
> > > +}
> > > +
> > > +/**
> > > + * xe_create_cmdbuf:
> > > + * @cmd_buf Pointer to the xe_buffer structure representing the
> > command buffer.
> > > + * @fill_func Pointer to the function that fills the command buffer.
> > > + * @dst_va Virtual address of the memory location where val need
> > to store.
> > > + * @val Value to be written to the memory locations.
> > > + * @eci Pointer to the engine class instance for execution.
> > > + *
> > > + * Creates a command buffer, fills it with commands using the
> > provided fill
> > > + * function, and sets up the execution queue for submission.
> > > + */
> > > +void xe_create_cmdbuf(struct xe_buffer *cmd_buf,
> > xe_cmdbuf_fill_func_t fill_func,
> > > + uint64_t dst_va, uint32_t val,
> > > + struct drm_xe_engine_class_instance *eci)
> > > +{
> > > + /*
> > > + * make some room for a exec_ufence, which will be used to
> > sync the
> > > + * submission of this command....
> > > + */
> > > + cmd_buf->size = xe_bb_size(cmd_buf->fd,
> > > + cmd_buf->size +
> > PAGE_ALIGN_UFENCE);
> > > + xe_create_buffer(cmd_buf);
> > > + cmd_buf->exec_queue = xe_exec_queue_create(cmd_buf-
> > >fd,
> > > + cmd_buf->vm, eci,
> > 0);
> > > + fill_func(cmd_buf->cpu_addr, dst_va, val);
> > > +}
> > > +
> > > +/**
> > > + * xe_destroy_cmdbuf:
> > > + * @cmd_buf Pointer to the xe_buffer structure representing the
> > command buffer.
> > > + *
> > > + * Destroys a command buffer created by xe_create_cmdbuf and
> > releases
> > > + * associated resources.
> > > + */
> > > +void xe_destroy_cmdbuf(struct xe_buffer *cmd_buf)
> > > +{
> > > + xe_exec_queue_destroy(cmd_buf->fd, cmd_buf-
> > >exec_queue);
> > > + xe_destroy_buffer(cmd_buf);
> > > +}
> > > +
> > > +/**
> > > + * xe_cmdbuf_exec_ufence_gpuva:
> > > + * @cmd_buf Pointer to the xe_buffer structure representing the
> > command buffer.
> > > + *
> > > + * Returns the GPU virtual address of the execution user fence
> > located at the
> > > + * end of the command buffer.
> > > + */
> > > +uint64_t xe_cmdbuf_exec_ufence_gpuva(struct xe_buffer
> > *cmd_buf)
> > > +{
> > > + /* the last 8 bytes of the cmd buffer is used as ufence */
> > > + return (uint64_t)cmd_buf->gpu_addr + cmd_buf->size -
> > UFENCE_LENGTH;
> > > +}
> > > +
> > > +/**
> > > + * xe_cmdbuf_exec_ufence_cpuva:
> > > + * @cmd_buf Pointer to the xe_buffer structure representing the
> > command buffer.
> > > + *
> > > + * Returns the CPU virtual address of the execution user fence
> > located at the
> > > + * end of the command buffer.
> > > + */
> > > +uint64_t *xe_cmdbuf_exec_ufence_cpuva(struct xe_buffer
> > *cmd_buf)
> > > +{
> > > + /* the last 8 bytes of the cmd buffer is used as ufence */
> > > + return cmd_buf->cpu_addr + cmd_buf->size -
> > UFENCE_LENGTH;
> > > +}
> > > +
> > > static bool __region_belongs_to_regions_type(struct
> > drm_xe_mem_region *region,
> > > uint32_t
> > *mem_regions_type,
> > > int num_regions)
> > > diff --git a/lib/xe/xe_util.h b/lib/xe/xe_util.h
> > > index 06ebd3c2a..df3d81801 100644
> > > --- a/lib/xe/xe_util.h
> > > +++ b/lib/xe/xe_util.h
> > > @@ -14,6 +14,39 @@
> > >
> > > #include "xe_query.h"
> > >
> > > +#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
> > > +#define PAGE_ALIGN_UFENCE 4096
> > > +#define UFENCE_LENGTH 8
> > > +
> > > +struct xe_buffer {
> > > + void *cpu_addr;
> > > + uint64_t gpu_addr;
> > > + /*the user fence used to vm bind this buffer*/
> > > + uint64_t *bind_ufence;
> > > + uint64_t size;
> > > + uint32_t flag;
> > > + uint32_t vm;
> > > + uint32_t bo;
> > > + uint32_t placement;
> > > + uint32_t bind_queue;
> > > + /*only a cmd buffer has a exec queue*/
> > > + uint32_t exec_queue;
> > > + int fd;
> > > + bool is_userptr;
> > > +};
> > > +
> > > +typedef void (*xe_cmdbuf_fill_func_t) (uint32_t *batch, uint64_t
> > dst_gpu_va, uint32_t val);
> > > +void xe_create_buffer(struct xe_buffer *buffer);
> > > +void xe_create_cmdbuf(struct xe_buffer *cmd_buf,
> > xe_cmdbuf_fill_func_t fill_func,
> > > + uint64_t dst_va, uint32_t val, struct
> > drm_xe_engine_class_instance *eci);
> > > +uint64_t xe_cmdbuf_exec_ufence_gpuva(struct xe_buffer
> > *cmd_buf);
> > > +uint64_t *xe_cmdbuf_exec_ufence_cpuva(struct xe_buffer
> > *cmd_buf);
> > > +void xe_insert_store(uint32_t *batch, uint64_t dst_va, uint32_t
> > val);
> > > +void xe_submit_cmd(struct xe_buffer *cmdbuf);
> > > +int64_t __xe_submit_cmd(struct xe_buffer *cmdbuf);
> > > +void xe_destroy_buffer(struct xe_buffer *buffer);
> > > +void xe_destroy_cmdbuf(struct xe_buffer *cmd_buf);
> > > +
> > > #define XE_IS_SYSMEM_MEMORY_REGION(fd, region) \
> > > (xe_region_class(fd, region) ==
> > DRM_XE_MEM_REGION_CLASS_SYSMEM)
> > > #define XE_IS_VRAM_MEMORY_REGION(fd, region) \
> > > --
> > > 2.26.3
> > >
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