Re: [PATCH i-g-t v4] tools/xe-perf-recorder: Add mmio-trigger support

On Mon, 20 Jul 2026 20:32:35 -0700, Shekhar Chauhan wrote:
>
> Add mmio-trigger support to xe-perf-recorder, to justify the
> whitelisting of OA MMIO Trigger Registers in XeKMD.
>
> Signed-off-by: Shekhar Chauhan <[email protected]>
> ---
>  tools/xe-perf/xe_perf_recorder.c | 118 ++++++++++++++++++++++++++++++-
>  1 file changed, 116 insertions(+), 2 deletions(-)
>
> diff --git a/tools/xe-perf/xe_perf_recorder.c b/tools/xe-perf/xe_perf_recorder.c
> index 61c3f6945..c69050b43 100644
> --- a/tools/xe-perf/xe_perf_recorder.c
> +++ b/tools/xe-perf/xe_perf_recorder.c
> @@ -26,19 +26,28 @@
>  #include <unistd.h>
>
>  #include "igt_core.h"
> +#include "intel_batchbuffer.h"
>  #include "intel_chipset.h"
>  #include "ioctl_wrappers.h"
>  #include "linux_scaffold.h"
> +#include "xe/xe_ioctl.h"
>  #include "xe/xe_oa.h"
>  #include "xe/xe_oa_data.h"
>  #include "xe/xe_query.h"
>
>  #include "xe_perf_recorder_commands.h"
>
> -#define ALIGN(v, a) (((v) + (a)-1) & ~((a)-1))
> -#define ARRAY_SIZE(arr) (sizeof(arr)/sizeof((arr)[0]))
>  #define MAX(a,b) ((a) > (b) ? (a) : (b))
>  #define MIN(a,b) ((a) < (b) ? (a) : (b))
> +#define OAG_MMIOTRIGGER 0xdb1c
> +#define OAMERT_MMIOTRIGGER 0x1453cc
> +#define OAM_MMIOTRIGGER_OFFSET 0x1d0
> +#define MEDIA_GT_GSI_OFFSET 0x380000
> +#define XE_OAM_SAG_BASE_ADJ (MEDIA_GT_GSI_OFFSET + 0x13000)
> +#define XE_OAM_SCMI_0_BASE_ADJ (MEDIA_GT_GSI_OFFSET + 0x14000)
> +#define XE_OAM_SCMI_1_BASE_ADJ (MEDIA_GT_GSI_OFFSET + 0x14800)
> +#define OAREPORT_REASON_MASK 0x3f
> +#define OAREPORT_REASON_SHIFT 19
>
>  struct circular_buffer {
>	char   *data;
> @@ -354,8 +363,50 @@ struct recording_context {
>	int oa_unit_id;
>	struct drm_xe_oa_unit *oa_unit;
>	struct drm_xe_engine_class_instance *hwe;
> +
> +	uint32_t vm;
> +	uint32_t exec_queue;
> +	struct intel_bb *ibb;
>  };
>
> +static uint32_t oa_unit_mmio_trigger_reg(struct recording_context *ctx)
> +{
> +	const struct drm_xe_oa_unit *oau = ctx->oa_unit;
> +
> +	switch (oau->oa_unit_type) {
> +	case DRM_XE_OA_UNIT_TYPE_OAM: {
> +		struct drm_xe_query_oa_units *qoa = xe_oa_units(ctx->drm_fd);
> +		uint8_t *poau = (uint8_t *)&qoa->oa_units[0];
> +		int first_oam_id = -1;
> +
> +		/* Find the first OAM unit, as in oa_unit_by_type() */
> +		for (int i = 0; i < qoa->num_oa_units; i++) {
> +			struct drm_xe_oa_unit *u = (struct drm_xe_oa_unit *)poau;
> +
> +			if (u->oa_unit_type == DRM_XE_OA_UNIT_TYPE_OAM) {
> +				first_oam_id = u->oa_unit_id;
> +				break;
> +			}
> +			poau += sizeof(*u) + u->num_engines * sizeof(u->eci[0]);
> +		}
> +
> +		assert(first_oam_id != -1);
> +
> +		if (oau->oa_unit_id == first_oam_id)
> +			return XE_OAM_SCMI_0_BASE_ADJ + OAM_MMIOTRIGGER_OFFSET;
> +		return XE_OAM_SCMI_1_BASE_ADJ + OAM_MMIOTRIGGER_OFFSET;
> +	}
> +	case DRM_XE_OA_UNIT_TYPE_OAM_SAG:
> +		return XE_OAM_SAG_BASE_ADJ + OAM_MMIOTRIGGER_OFFSET;
> +	case DRM_XE_OA_UNIT_TYPE_MERT:
> +		return OAMERT_MMIOTRIGGER;
> +	case DRM_XE_OA_UNIT_TYPE_OAG:
> +		return OAG_MMIOTRIGGER;
> +	default:
> +		assert(0);
> +	}
> +}
> +
>  static void set_fd_flags(int fd, int flags)
>  {
>	int old = fcntl(fd, F_GETFL, 0);
> @@ -569,6 +620,28 @@ static bool write_stream_status(struct recording_context *ctx, FILE *output)
>	return true;
>  }
>
> +static uint32_t
> +report_reason(const uint32_t *report)
> +{
> +	return (report[0] >> OAREPORT_REASON_SHIFT) & OAREPORT_REASON_MASK;
> +}
> +
> +static void
> +check_mmio_trigger_report(struct recording_context *ctx, const void *report)
> +{
> +	const struct xe_oa_format *fmt = &oa_formats[ctx->metric_set->perf_oa_format];
> +	const uint32_t *report_32 = report;
> +	uint64_t value;
> +
> +	if (report_reason(report_32))
> +		return;
> +
> +	value = (fmt->header == HDR_64_BIT) ? ((const uint64_t *)report)[2] : report_32[2];
> +
> +	if (value == 0xc0ffee01 || value == 0xc0ffee02)
> +		fprintf(stdout, "Received trigger report with value 0x%" PRIx64 "\n", value);
> +}
> +
>  static bool write_stream_data(struct recording_context *ctx,
>			      char *data, ssize_t size, FILE *output)
>  {
> @@ -582,6 +655,8 @@ static bool write_stream_data(struct recording_context *ctx,
>			.size = sizeof(header) + format_size,
>		};
>
> +		check_mmio_trigger_report(ctx, data);

I have merged my bug fix patch, so this now looks correct!

Rest lgtm now, so this is:

Reviewed-by: Ashutosh Dixit <[email protected]>

> +
>		if (fwrite(&header, sizeof(header), 1, output) != 1)
>			return false;
>
> @@ -699,6 +774,22 @@ write_correlation_timestamps(struct recording_context *ctx, FILE *output)
>	return write_saved_correlation_timestamps(output, &corr);
>  }
>
> +static void emit_mmio_triggered_report(struct intel_bb *ibb, uint32_t reg, uint32_t value)
> +{
> +	intel_bb_out(ibb, MI_LOAD_REGISTER_IMM(1));
> +	intel_bb_out(ibb, reg);
> +	intel_bb_out(ibb, value);
> +}
> +
> +static void emit_oa_trigger(struct recording_context *ctx, uint32_t value)
> +{
> +	emit_mmio_triggered_report(ctx->ibb, oa_unit_mmio_trigger_reg(ctx), value);
> +
> +	intel_bb_flush_render(ctx->ibb);
> +	intel_bb_sync(ctx->ibb);
> +	intel_bb_reset(ctx->ibb, false);
> +}
> +
>  static void
>  read_command_file(struct recording_context *ctx)
>  {
> @@ -714,6 +805,9 @@ read_command_file(struct recording_context *ctx)
>		uint8_t *dump = malloc(len);
>		FILE *file;
>
> +		emit_oa_trigger(ctx, 0xc0ffee02);
> +		write_perf_data(ctx->output_stream, ctx);
> +
>		while (offset < len &&
>		       ((ret = read(ctx->command_fifo_fd,
>				    (void *) dump + offset, len - offset)) > 0
> @@ -837,6 +931,13 @@ usage(const char *name)
>  static void
>  teardown_recording_context(struct recording_context *ctx)
>  {
> +	if (ctx->ibb)
> +		intel_bb_destroy(ctx->ibb);
> +	if (ctx->exec_queue)
> +		xe_exec_queue_destroy(ctx->drm_fd, ctx->exec_queue);
> +	if (ctx->vm)
> +		xe_vm_destroy(ctx->drm_fd, ctx->vm);
> +
>	if (ctx->topology)
>		free(ctx->topology);
>
> @@ -914,6 +1015,14 @@ static int assign_oa_unit(int fd, struct recording_context *ctx)
>	return -1;
>  }
>
> +static void init_mmio_trigger_ctx(struct recording_context *ctx)
> +{
> +	ctx->vm = xe_vm_create(ctx->drm_fd, 0, 0);
> +	ctx->exec_queue = xe_exec_queue_create(ctx->drm_fd, ctx->vm, ctx->hwe, 0);
> +	ctx->ibb = intel_bb_create_with_context(ctx->drm_fd, ctx->exec_queue, ctx->vm,
> +						NULL, BATCH_SZ);
> +}
> +
>  int
>  main(int argc, char *argv[])
>  {
> @@ -1182,6 +1291,9 @@ main(int argc, char *argv[])
>		goto fail;
>	}
>
> +	init_mmio_trigger_ctx(&ctx);
> +	emit_oa_trigger(&ctx, 0xc0ffee01);
> +
>	corr_period_ns = corr_period * 1000000000ul;
>	poll_time_ns = corr_period_ns;
>
> @@ -1229,6 +1341,8 @@ main(int argc, char *argv[])
>		}
>	}
>
> +	/* Emit second OA trigger for the case where circular buffer is not used */
> +	emit_oa_trigger(&ctx, 0xc0ffee02);
>	fprintf(stdout, "Exiting...\n");
>
>	if (!write_perf_data(ctx.output_stream, &ctx)) {
> --
> 2.53.0
>