[PATCH 2/2] drm/xe/guc: Add support for NPK as a GuC log target

[Lucas De Marchi]

On Wed, Jun 11, 2025 at 02:05:53PM -0700, John.C.Harrison at Intel.com wrote:
>From: John Harrison <John.C.Harrison at Intel.com>
>
>The GuC has an option to write log data via NPK. This is basically a
>magic IO address that GuC writes arbitrary data to and which can be
>logged by a suitable hardware logger. This can allow retrieval of the
>GuC log in hardware debug environments even when the system as a whole
>dies horribly.
>
>Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
>---
> drivers/gpu/drm/xe/xe_guc.c    | 4 ++++
> drivers/gpu/drm/xe/xe_module.c | 4 ++++
> drivers/gpu/drm/xe/xe_module.h | 1 +
> 3 files changed, 9 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
>index e16d19b44bcc..9c0e3113f7d5 100644
>--- a/drivers/gpu/drm/xe/xe_guc.c
>+++ b/drivers/gpu/drm/xe/xe_guc.c
>@@ -35,6 +35,7 @@
> #include "xe_guc_submit.h"
> #include "xe_memirq.h"
> #include "xe_mmio.h"
>+#include "xe_module.h"
> #include "xe_platform_types.h"
> #include "xe_sriov.h"
> #include "xe_uc.h"
>@@ -74,6 +75,9 @@ static u32 guc_ctl_debug_flags(struct xe_guc *guc)
> 	else
> 		flags |= FIELD_PREP(GUC_LOG_VERBOSITY, GUC_LOG_LEVEL_TO_VERBOSITY(level));
>
>+	if (xe_modparam.guc_log_target)
>+		flags |= FIELD_PREP(GUC_LOG_DESTINATION, xe_modparam.guc_log_target);

is this supported across the board for all platforms and firmware
versions? Otherwise, what'd happen if you have and old igfx and you are
debugging a new dgfx? or vice-versa.

We should probably need to sanitize the user input here?

Lucas De Marchi

>+
> 	return flags;
> }
>
>diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
>index 1c4dfafbcd0b..fc8c681819b9 100644
>--- a/drivers/gpu/drm/xe/xe_module.c
>+++ b/drivers/gpu/drm/xe/xe_module.c
>@@ -21,6 +21,7 @@
> struct xe_modparam xe_modparam = {
> 	.probe_display = true,
> 	.guc_log_level = 3,
>+	.guc_log_target = 0,
> 	.force_probe = CONFIG_DRM_XE_FORCE_PROBE,
> #ifdef CONFIG_PCI_IOV
> 	.max_vfs = IS_ENABLED(CONFIG_DRM_XE_DEBUG) ? ~0 : 0,
>@@ -45,6 +46,9 @@ MODULE_PARM_DESC(vram_bar_size, "Set the vram bar size (in MiB) - <0=disable-res
> module_param_named(guc_log_level, xe_modparam.guc_log_level, int, 0600);
> MODULE_PARM_DESC(guc_log_level, "GuC firmware logging level (0=disable, 1..5=enable with verbosity min..max)");
>
>+module_param_named(guc_log_target, xe_modparam.guc_log_target, int, 0600);
>+MODULE_PARM_DESC(guc_log_target, "GuC firmware logging target (0=memory [default], 1 = NPK, 2 = memory + NPK)");
>+
> module_param_named_unsafe(guc_firmware_path, xe_modparam.guc_firmware_path, charp, 0400);
> MODULE_PARM_DESC(guc_firmware_path,
> 		 "GuC firmware path to use instead of the default one");
>diff --git a/drivers/gpu/drm/xe/xe_module.h b/drivers/gpu/drm/xe/xe_module.h
>index 5a3bfea8b7b4..4d978f6f26b6 100644
>--- a/drivers/gpu/drm/xe/xe_module.h
>+++ b/drivers/gpu/drm/xe/xe_module.h
>@@ -14,6 +14,7 @@ struct xe_modparam {
> 	bool probe_display;
> 	u32 force_vram_bar_size;
> 	int guc_log_level;
>+	int guc_log_target;
> 	char *guc_firmware_path;
> 	char *huc_firmware_path;
> 	char *gsc_firmware_path;
>-- 
>2.49.0
>