Re: [PATCH 06/10] drm/xe/guc: Add configfs support for guc_log_level

On Fri, 2026-08-07 at 19:45 +0000, Stuart Summers wrote:
> Allow the GuC log level to be selected per-device via configfs in
> addition to the existing 'guc_log_level' module parameter. The
> configfs
> attribute lives under the new 'debug' configfs subdirectory:
> 
>   /sys/kernel/config/xe/<bdf>/debug/guc_log_level
> 
> When the configfs attribute is set to a valid level (0-5), it
> overrides
> the module parameter for that device. The default value is -1
> (XE_GUC_LOG_LEVEL_UNSET), which means 'unset' and falls back to the
> 'guc_log_level' module parameter, ensuring existing users that rely
> solely on the module parameter are unaffected by this change.
> 
> The module parameter implementation itself is untouched.
> 
> Note that the expectation is a user will only set the log level when
> CONFIG_DRM_XE_DEBUG is set.
> 
> Signed-off-by: Stuart Summers <[email protected]>
> Assisted-by: Copilot:claude-sonnet-4.6,claude-opus-4.7,claude-sonnet-
> 5,claude-opus-5
> ---
>  drivers/gpu/drm/xe/xe_configfs.c       |  2 +
>  drivers/gpu/drm/xe/xe_configfs_debug.c | 84
> ++++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_configfs_debug.h |  7 +++
>  drivers/gpu/drm/xe/xe_configfs_types.h |  1 +
>  drivers/gpu/drm/xe/xe_defaults.h       |  3 +
>  drivers/gpu/drm/xe/xe_guc_log.c        |  3 +-
>  6 files changed, 99 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_configfs.c
> b/drivers/gpu/drm/xe/xe_configfs.c
> index 111aacce8a84..ea09d5f9e925 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.c
> +++ b/drivers/gpu/drm/xe/xe_configfs.c
> @@ -100,6 +100,7 @@ const struct xe_config_device
> xe_configfs_device_defaults = {
>         .debug = {
>                 .engines_allowed = U64_MAX,
>                 .gt_types_allowed = U64_MAX,
> +               .guc_log_level = XE_GUC_LOG_LEVEL_UNSET,
>                 .enable_multi_queue = true,
>                 .enable_psmi = false,
>                 .survivability_mode = false,
> @@ -418,6 +419,7 @@ static void dump_custom_dev_config(struct pci_dev
> *pdev,
>  #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
>         PRI_CUSTOM_ATTR("%llx", debug.engines_allowed);
>         PRI_CUSTOM_ATTR("%llx", debug.gt_types_allowed);
> +       PRI_CUSTOM_ATTR("%d", debug.guc_log_level);
>         PRI_CUSTOM_ATTR("%d", debug.enable_multi_queue);
>         PRI_CUSTOM_ATTR("%d", debug.enable_psmi);
>         PRI_CUSTOM_ATTR("%d", debug.survivability_mode);
> diff --git a/drivers/gpu/drm/xe/xe_configfs_debug.c
> b/drivers/gpu/drm/xe/xe_configfs_debug.c
> index b2667573efbe..eb3c3bd9c33e 100644
> --- a/drivers/gpu/drm/xe/xe_configfs_debug.c
> +++ b/drivers/gpu/drm/xe/xe_configfs_debug.c
> @@ -17,6 +17,7 @@
>  #include "xe_configfs_debug.h"
>  #include "xe_configfs_types.h"
>  #include "xe_gt_types.h"
> +#include "xe_guc_log.h"
>  #include "xe_hw_engine_types.h"
>  #include "xe_pci_types.h"
>  
> @@ -44,6 +45,7 @@
>   *             ├── ctx_restore_post_bb
>   *             ├── engines_allowed
>   *             ├── gt_types_allowed
> + *             ├── guc_log_level
>   *             ├── enable_multi_queue
>   *             ├── enable_psmi
>   *             └── survivability_mode
> @@ -167,6 +169,27 @@
>   *
>   *     # echo '' >
> /sys/kernel/config/xe/0000:03:00.0/debug/gt_types_allowed
>   *
> + * GuC log level:
> + * --------------
> + *
> + * Set the GuC firmware logging verbosity for this device. Accepted
> values
> + * match the ``guc_log_level`` module parameter:
> + *
> + *   - 0: disable
> + *   - 1: normal (non-verbose)
> + *   - 2..%GUC_LOG_LEVEL_MAX: verbose levels
> + *
> + * Example::
> + *
> + *     # echo 3 >
> /sys/kernel/config/xe/0000:03:00.0/debug/guc_log_level
> + *
> + * The default value is %XE_GUC_LOG_LEVEL_UNSET (-1), which means
> the value
> + * of the ``guc_log_level`` module parameter is used. Any value
> greater
> + * than -1 written to this attribute overrides the module parameter
> for
> + * this device.
> + *
> + * This attribute can only be set before binding to the device.
> + *
>   * Enable multi-queue
>   * ------------------
>   *
> @@ -758,6 +781,65 @@ static ssize_t gt_types_allowed_store(struct
> config_item *item, const char *page
>         return len;
>  }
>  
> +/**
> + * xe_configfs_get_guc_log_level - get configfs guc_log_level
> setting
> + * @pdev: pci device
> + *
> + * Returns the guc_log_level value configured via configfs. If the
> configfs
> + * value is negative (the default is %XE_GUC_LOG_LEVEL_UNSET, -1),
> the value
> + * of the ``guc_log_level`` module parameter is returned instead,
> allowing
> + * the configfs entry to override the module parameter without
> affecting
> + * users that rely solely on the module parameter.
> + *
> + * Return: GuC log level to use for this device.
> + */
> +int xe_configfs_get_guc_log_level(struct pci_dev *pdev)
> +{
> +       struct xe_config_group_device *dev = find_device(pdev);
> +       int level = xe_modparam.guc_log_level;
> +
> +       if (!dev)
> +               return level;
> +
> +       scoped_guard(mutex, &dev->lock)
> +               if (dev->config.debug.guc_log_level >= 0)
> +                       level = dev->config.debug.guc_log_level;
> +
> +       config_group_put(&dev->group);
> +out:

Sashiko called out correctly that I forgot to drop the extra label
here... I'll post an update here shortly for this. I also need to post
IGT changes to xe_configfs to account for these new debug-specific
changes.

Thanks,
Stuart

> +       return level;
> +}
> +
> +static ssize_t guc_log_level_show(struct config_item *item, char
> *page)
> +{
> +       struct xe_config_device *dev =
> xe_configfs_subgroup_to_device(item);
> +
> +       return sprintf(page, "%d\n", dev->debug.guc_log_level);
> +}
> +
> +static ssize_t guc_log_level_store(struct config_item *item, const
> char *page, size_t len)
> +{
> +       struct xe_config_group_device *dev =
> xe_configfs_subgroup_to_group_device(item);
> +       int val;
> +       int ret;
> +
> +       ret = kstrtoint(page, 0, &val);
> +       if (ret)
> +               return ret;
> +
> +       if (val != XE_GUC_LOG_LEVEL_UNSET &&
> +           (val < 0 || val > GUC_LOG_LEVEL_MAX))
> +               return -EINVAL;
> +
> +       guard(mutex)(&dev->lock);
> +       if (xe_configfs_is_bound(dev))
> +               return -EBUSY;
> +
> +       dev->config.debug.guc_log_level = val;
> +
> +       return len;
> +}
> +
>  /**
>   * xe_configfs_get_enable_multi_queue - get configfs
> enable_multi_queue setting
>   * @pdev: pci device
> @@ -904,6 +986,7 @@ CONFIGFS_ATTR(, ctx_restore_mid_bb);
>  CONFIGFS_ATTR(, ctx_restore_post_bb);
>  CONFIGFS_ATTR(, engines_allowed);
>  CONFIGFS_ATTR(, gt_types_allowed);
> +CONFIGFS_ATTR(, guc_log_level);
>  CONFIGFS_ATTR(, enable_multi_queue);
>  CONFIGFS_ATTR(, enable_psmi);
>  CONFIGFS_ATTR(, survivability_mode);
> @@ -913,6 +996,7 @@ static struct configfs_attribute
> *xe_configfs_debug_attrs[] = {
>         &attr_ctx_restore_post_bb,
>         &attr_engines_allowed,
>         &attr_gt_types_allowed,
> +       &attr_guc_log_level,
>         &attr_enable_multi_queue,
>         &attr_enable_psmi,
>         &attr_survivability_mode,
> diff --git a/drivers/gpu/drm/xe/xe_configfs_debug.h
> b/drivers/gpu/drm/xe/xe_configfs_debug.h
> index 4a027ea2082d..5fe39bb72f00 100644
> --- a/drivers/gpu/drm/xe/xe_configfs_debug.h
> +++ b/drivers/gpu/drm/xe/xe_configfs_debug.h
> @@ -7,7 +7,9 @@
>  
>  #include <linux/types.h>
>  
> +#include "xe_defaults.h"
>  #include "xe_hw_engine_types.h"
> +#include "xe_module.h"
>  
>  struct pci_dev;
>  struct xe_config_device;
> @@ -24,6 +26,7 @@ u32 xe_configfs_get_ctx_restore_post_bb(struct
> pci_dev *pdev,
>  u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev);
>  bool xe_configfs_primary_gt_allowed(struct pci_dev *pdev);
>  bool xe_configfs_media_gt_allowed(struct pci_dev *pdev);
> +int xe_configfs_get_guc_log_level(struct pci_dev *pdev);
>  bool xe_configfs_get_enable_multi_queue(struct pci_dev *pdev);
>  bool xe_configfs_get_psmi_enabled(struct pci_dev *pdev);
>  bool xe_configfs_get_survivability_mode(struct pci_dev *pdev);
> @@ -42,6 +45,10 @@ static inline u32
> xe_configfs_get_ctx_restore_post_bb(struct pci_dev *pdev,
>  static inline u64 xe_configfs_get_engines_allowed(struct pci_dev
> *pdev) { return U64_MAX; }
>  static inline bool xe_configfs_primary_gt_allowed(struct pci_dev
> *pdev) { return true; }
>  static inline bool xe_configfs_media_gt_allowed(struct pci_dev
> *pdev) { return true; }
> +static inline int xe_configfs_get_guc_log_level(struct pci_dev
> *pdev)
> +{
> +       return xe_modparam.guc_log_level;
> +}
>  static inline bool xe_configfs_get_enable_multi_queue(struct pci_dev
> *pdev) { return true; }
>  static inline bool xe_configfs_get_psmi_enabled(struct pci_dev
> *pdev) { return false; }
>  static inline bool xe_configfs_get_survivability_mode(struct pci_dev
> *pdev) { return false; }
> diff --git a/drivers/gpu/drm/xe/xe_configfs_types.h
> b/drivers/gpu/drm/xe/xe_configfs_types.h
> index 6e8ba6f85fad..e9460c3de891 100644
> --- a/drivers/gpu/drm/xe/xe_configfs_types.h
> +++ b/drivers/gpu/drm/xe/xe_configfs_types.h
> @@ -38,6 +38,7 @@ struct xe_config_group_device {
>                         struct wa_bb
> ctx_restore_post_bb[XE_ENGINE_CLASS_MAX];
>                         u64 engines_allowed;
>                         u64 gt_types_allowed;
> +                       int guc_log_level;
>                         bool enable_multi_queue;
>                         bool enable_psmi;
>                         bool survivability_mode;
> diff --git a/drivers/gpu/drm/xe/xe_defaults.h
> b/drivers/gpu/drm/xe/xe_defaults.h
> index c8ae1d5f3d60..df88078e84b8 100644
> --- a/drivers/gpu/drm/xe/xe_defaults.h
> +++ b/drivers/gpu/drm/xe/xe_defaults.h
> @@ -13,6 +13,9 @@
>  #define XE_DEFAULT_GUC_LOG_LEVEL               1
>  #endif
>  
> +/* Sentinel value for guc_log_level configfs: not set, fall back to
> module param */
> +#define XE_GUC_LOG_LEVEL_UNSET                 -1
> +
>  #define
> XE_DEFAULT_PROBE_DISPLAY               IS_ENABLED(CONFIG_DRM_XE_DISPL
> AY)
>  #define XE_DEFAULT_VRAM_BAR_SIZE               0
>  #define
> XE_DEFAULT_FORCE_PROBE                 CONFIG_DRM_XE_FORCE_PROBE
> diff --git a/drivers/gpu/drm/xe/xe_guc_log.c
> b/drivers/gpu/drm/xe/xe_guc_log.c
> index 538d4df0f7aa..531b9759d520 100644
> --- a/drivers/gpu/drm/xe/xe_guc_log.c
> +++ b/drivers/gpu/drm/xe/xe_guc_log.c
> @@ -13,6 +13,7 @@
>  #include "abi/guc_lfd_abi.h"
>  #include "regs/xe_guc_regs.h"
>  #include "xe_bo.h"
> +#include "xe_configfs_debug.h"
>  #include "xe_devcoredump.h"
>  #include "xe_force_wake.h"
>  #include "xe_gt_printk.h"
> @@ -637,7 +638,7 @@ int xe_guc_log_init(struct xe_guc_log *log)
>  
>         xe_map_memset(xe, &bo->vmap, 0, 0, xe_bo_size(bo));
>         log->bo = bo;
> -       log->level = xe_modparam.guc_log_level;
> +       log->level = xe_configfs_get_guc_log_level(to_pci_dev(xe-
> >drm.dev));
>  
>         return 0;
>  }