Re: [PATCH i-g-t] tests/intel/xe_tlb: Check TLB invalidation

[Matthew Brost <matthew.brost@intel.com>]

On Wed, May 22, 2024 at 03:17:40PM +0530, sai.gowtham.ch@intel.com wrote:
> From: Sai Gowtham Ch <sai.gowtham.ch@intel.com>
> 
> Test validates TLB invalidation by binding different buffer objects
> with the same vma and submitting workload simultaneously, Ideally
> expecting gpu to handle pages by invalidating and  avoding page faults.
> 

I don't think this test is creating new coverage beyond existing tests. There
are many tests that unbind and rebind something to the same address (e.g.
xe_exec_basic --r rebind), granted this is the same BO though. A userptr
invalidation, however, triggers an internal (KMD-triggered) rebind, and we also
have many tests which do this as well (e.g. xe_exec_basic --r invalidate). In
this case, the rebound data is different.

With that, I do not think the test warrants merging as it does not provide any
additional value.

Matt

> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
> Signed-off-by: Sai Gowtham Ch <sai.gowtham.ch@intel.com>
> ---
>  tests/intel/xe_tlb.c | 178 +++++++++++++++++++++++++++++++++++++++++++
>  tests/meson.build    |   1 +
>  2 files changed, 179 insertions(+)
>  create mode 100644 tests/intel/xe_tlb.c
> 
> diff --git a/tests/intel/xe_tlb.c b/tests/intel/xe_tlb.c
> new file mode 100644
> index 000000000..8e6dba5a3
> --- /dev/null
> +++ b/tests/intel/xe_tlb.c
> @@ -0,0 +1,178 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> +* Copyright © 2024 Intel Corporation
> +*
> +* Authors:
> +*    Sai Gowtham Ch <sai.gowtham.ch@intel.com>
> +*/
> +#include "igt.h"
> +#include "lib/igt_syncobj.h"
> +#include "xe/xe_ioctl.h"
> +#include "xe/xe_query.h"
> +#include "xe_drm.h"
> +
> +/**
> + * TEST: Check Translation Lookaside Buffer Invalidation.
> + * Category: Software building block
> + * Mega feature: General Core features
> + * Sub-category: CMD submission
> + * Functionality: TLB invalidate
> + * Test category: functionality test
> + */
> +
> +struct data {
> +	uint32_t batch[16];
> +	uint32_t data;
> +	uint64_t addr;
> +};
> +
> +static void store_dword_batch(struct data *data, uint64_t addr, int value)
> +{
> +	int b;
> +	uint64_t batch_offset = (char *)&(data->batch) - (char *)data;
> +	uint64_t batch_addr = addr + batch_offset;
> +	uint64_t sdi_offset = (char *)&(data->data) - (char *)data;
> +	uint64_t sdi_addr = addr + sdi_offset;
> +
> +	b = 0;
> +	data->batch[b++] = MI_STORE_DWORD_IMM_GEN4;
> +	data->batch[b++] = sdi_addr;
> +	data->batch[b++] = sdi_addr >> 32;
> +	data->batch[b++] = value;
> +	data->batch[b++] = MI_BATCH_BUFFER_END;
> +	igt_assert(b <= ARRAY_SIZE(data->batch));
> +
> +	data->addr = batch_addr;
> +}
> +
> +const char *xe_trace_enable_path =
> +				"/sys/kernel/debug/tracing/events/xe/enable";
> +const char *trace_path = "/sys/kernel/tracing/trace";
> +
> +static bool sysfs_write(const char *file, const char *value)
> +{
> +	FILE *fp = fopen(file, "w");
> +
> +	igt_assert_f(fp, "error in opening file %s\n", file);
> +	igt_assert_f(fwrite(value, 1, strlen(value), fp) == strlen(value),
> +			"failed to update sysfs tracing node %s\n", file);
> +	fclose(fp);
> +	return 0;
> +}
> +
> +static void start_tracing(void)
> +{
> +	sysfs_write(xe_trace_enable_path, "1");
> +}
> +
> +static void validate_debugfs_trace(int fd)
> +{
> +	igt_assert(igt_debugfs_search(fd, trace_path, "tlb_invalidation_fence_create"));
> +}
> +
> +static void stop_tracing(void)
> +{
> +	sysfs_write(xe_trace_enable_path, "0");
> +}
> +
> +/**
> + * SUBTEST: basic-tlb
> + * Description: Check Translation Lookaside Buffer Invalidation.
> + */
> +static void tlb_invalidation(int fd, struct drm_xe_engine_class_instance *eci)
> +{
> +	struct drm_xe_sync sync[2] = {
> +		{ .type = DRM_XE_SYNC_TYPE_SYNCOBJ, .flags = DRM_XE_SYNC_FLAG_SIGNAL, },
> +		{ .type = DRM_XE_SYNC_TYPE_SYNCOBJ, .flags = DRM_XE_SYNC_FLAG_SIGNAL, }
> +	};
> +	struct drm_xe_exec exec = {
> +		.num_batch_buffer = 1,
> +		.num_syncs = 2,
> +		.syncs = to_user_pointer(&sync),
> +	};
> +	struct data *data1;
> +	struct data *data2;
> +	uint32_t vm;
> +	uint32_t exec_queue;
> +	uint32_t bind_engine;
> +	uint32_t syncobj;
> +	size_t bo_size;
> +	int value1 = 0x123456;
> +	int value2 = 0x123465;
> +	uint64_t addr = 0x100000;
> +	uint32_t bo1, bo2;
> +
> +	syncobj = syncobj_create(fd, 0);
> +	sync[0].handle = syncobj_create(fd, 0);
> +	sync[1].handle = syncobj;
> +
> +	vm = xe_vm_create(fd, 0, 0);
> +	bo_size = sizeof(*data1);
> +	bo_size = xe_bb_size(fd, bo_size);
> +
> +	bo1 = xe_bo_create(fd, vm, bo_size,
> +				   vram_if_possible(fd, eci->gt_id),
> +				   DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
> +	bo2 = xe_bo_create(fd, vm, bo_size,
> +				   vram_if_possible(fd, eci->gt_id),
> +				   DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
> +
> +	start_tracing();
> +	exec_queue = xe_exec_queue_create(fd, vm, eci, 0);
> +	bind_engine = xe_bind_exec_queue_create(fd, vm, 0);
> +	xe_vm_bind_async(fd, vm, bind_engine, bo1, 0, addr, bo_size, sync, 1);
> +	data1 = xe_bo_map(fd, bo1, bo_size);
> +
> +	store_dword_batch(data1, addr, value1);
> +	exec.exec_queue_id = exec_queue;
> +	exec.address = data1->addr;
> +	sync[0].flags &= ~DRM_XE_SYNC_FLAG_SIGNAL;
> +	sync[1].flags |= DRM_XE_SYNC_FLAG_SIGNAL;
> +	xe_exec(fd, &exec);
> +	igt_assert(syncobj_wait(fd, &syncobj, 1, INT64_MAX, 0, NULL));
> +
> +	xe_vm_bind_async(fd, vm, bind_engine, bo2, 0, addr, bo_size, sync, 1);
> +	data2 = xe_bo_map(fd, bo2, bo_size);
> +
> +	store_dword_batch(data2, addr, value2);
> +	exec.exec_queue_id = exec_queue;
> +	exec.address = data2->addr;
> +	sync[0].flags &= ~DRM_XE_SYNC_FLAG_SIGNAL;
> +	sync[1].flags |= DRM_XE_SYNC_FLAG_SIGNAL;
> +	xe_exec(fd, &exec);
> +	igt_assert(syncobj_wait(fd, &syncobj, 1, INT64_MAX, 0, NULL));
> +
> +	igt_assert_eq(data1->data, value1);
> +	igt_assert_eq(data2->data, value2);
> +	validate_debugfs_trace(fd);
> +
> +	syncobj_destroy(fd, sync[0].handle);
> +	syncobj_destroy(fd, syncobj);
> +	munmap(data1, bo_size);
> +	munmap(data2, bo_size);
> +	gem_close(fd, bo1);
> +	gem_close(fd, bo2);
> +
> +	xe_exec_queue_destroy(fd, exec_queue);
> +	xe_vm_destroy(fd, vm);
> +}
> +
> +igt_main
> +{
> +	int fd;
> +	struct drm_xe_engine *engine;
> +
> +	igt_fixture {
> +		fd = drm_open_driver(DRIVER_XE);
> +	}
> +
> +	igt_subtest("basic-tlb") {
> +		engine = xe_engine(fd, 0);
> +		tlb_invalidation(fd, &engine->instance);
> +	}
> +
> +	igt_fixture {
> +		stop_tracing();
> +		drm_close_driver(fd);
> +	}
> +}
> diff --git a/tests/meson.build b/tests/meson.build
> index 758ae090c..e4fee5ca0 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -316,6 +316,7 @@ intel_xe_progs = [
>  	'xe_spin_batch',
>  	'xe_sysfs_defaults',
>  	'xe_sysfs_scheduler',
> +	'xe_tlb',
>  ]
>  
>  msm_progs = [
> -- 
> 2.39.1
>