[PATCH v4] drm/xe: Add driver load error injection

Jani Nikula jani.nikula at linux.intel.com
Thu Aug 15 13:34:52 UTC 2024


On Wed, 14 Aug 2024, Francois Dugast <francois.dugast at intel.com> wrote:
> Those new macros inject errors by overriding return codes. They must
> manually be called, typically by turning this pattern:
>
>     err = foo();
>     if (err)
>         return err;
>
> into:
>
>     err = foo();
>     err = xe_device_inject_driver_probe_error(xe, err);
>     if (err)
>         return err;
>
> When CONFIG_DRM_XE_DEBUG is not set, this has no effect.
>
> When CONFIG_DRM_XE_DEBUG is set, the error code at checkpoint X will
> be overridden when the module argument inject_driver_load_error is
> set to value X. By doing so, it is possible to test proper error
> handling and improve robustness for current and future code. A few
> injection points are added in this patch but more need to be added.
> One way to use this error injection at driver probe is:
>
>     for i in {1..200}; do echo "Run $i"; modprobe xe inject_driver_probe_error=$i; rmmod xe; done
>
> In the future this is expected to be replaced by the infrastructure
> provided by fault-inject.h

See my comment on a previous version [1].

BR,
Jani.

[1] https://lore.kernel.org/r/87wmkkzold.fsf@intel.com


>
> v2: Fix style and build errors, modparam to 0 after probe, rename to
>     xe_device_inject_driver_probe_error, check type when compiled out,
>     add _return macro, move some uses to the beginning of the function
> v3: Rebase
> v4: Improve commit message and comments, keep if/return rather than
>     change the flow inside the macro (Lucas De Marchi)
>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> Signed-off-by: Francois Dugast <francois.dugast at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c       | 41 ++++++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_device.h       | 23 ++++++++++++++++
>  drivers/gpu/drm/xe/xe_device_types.h |  5 ++++
>  drivers/gpu/drm/xe/xe_gt.c           |  2 ++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf.c  |  2 ++
>  drivers/gpu/drm/xe/xe_guc.c          |  2 ++
>  drivers/gpu/drm/xe/xe_guc_ct.c       |  1 +
>  drivers/gpu/drm/xe/xe_mmio.c         |  5 ++++
>  drivers/gpu/drm/xe/xe_module.c       |  5 ++++
>  drivers/gpu/drm/xe/xe_module.h       |  3 ++
>  drivers/gpu/drm/xe/xe_pci.c          |  6 ++++
>  drivers/gpu/drm/xe/xe_pm.c           |  5 ++++
>  drivers/gpu/drm/xe/xe_sriov.c        |  6 ++++
>  drivers/gpu/drm/xe/xe_tile.c         |  4 +++
>  drivers/gpu/drm/xe/xe_uc.c           |  1 +
>  drivers/gpu/drm/xe/xe_wa.c           |  5 ++++
>  drivers/gpu/drm/xe/xe_wopcm.c        |  4 +++
>  17 files changed, 120 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 206328387150..a2ccdc4115ac 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -316,6 +316,7 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
>  	err = ttm_device_init(&xe->ttm, &xe_ttm_funcs, xe->drm.dev,
>  			      xe->drm.anon_inode->i_mapping,
>  			      xe->drm.vma_offset_manager, false, false);
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (WARN_ON(err))
>  		goto err;
>  
> @@ -474,6 +475,7 @@ static int xe_set_dma_info(struct xe_device *xe)
>  		goto mask_err;
>  
>  	err = dma_set_coherent_mask(xe->drm.dev, DMA_BIT_MASK(mask_size));
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (err)
>  		goto mask_err;
>  
> @@ -577,6 +579,7 @@ int xe_device_probe_early(struct xe_device *xe)
>  		return err;
>  
>  	err = wait_for_lmem_ready(xe);
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (err)
>  		return err;
>  
> @@ -745,6 +748,11 @@ int xe_device_probe(struct xe_device *xe)
>  	for_each_gt(gt, xe, id)
>  		xe_gt_sanitize_freq(gt);
>  
> +#ifdef CONFIG_DRM_XE_DEBUG
> +	/* After probe finishes, stop checking for error injection */
> +	xe_modparam.inject_driver_probe_error = 0;
> +#endif
> +
>  	return devm_add_action_or_reset(xe->drm.dev, xe_device_sanitize, xe);
>  
>  err_fini_display:
> @@ -995,3 +1003,36 @@ void xe_device_declare_wedged(struct xe_device *xe)
>  	for_each_gt(gt, xe, id)
>  		xe_gt_declare_wedged(gt);
>  }
> +
> +#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> +/**
> + * __xe_device_inject_driver_probe_error - Inject an error during device probe
> + * @xe: xe device instance
> + * @err_injected: the error to inject
> + * @err_real: the error returned by the actual function
> + * @func: the name of the function where this is called from
> + * @line: the line where this is called from
> + *
> + * This is not meant to be called directly, only through xe_device_inject_driver_probe_error.
> + *
> + * Return: err_real if != 0, err_injected otherwise
> + */
> +int __xe_device_inject_driver_probe_error(struct xe_device *xe, int err_injected, int err_real,
> +					  const char *func, int line)
> +{
> +	if (err_real != 0)
> +		return err_real;
> +
> +	if (xe->inject_driver_probe_error >= xe_modparam.inject_driver_probe_error)
> +		return 0;
> +
> +	if (++xe->inject_driver_probe_error < xe_modparam.inject_driver_probe_error)
> +		return 0;
> +
> +	drm_info(&xe->drm, "Injecting failure %d at checkpoint %u [%s:%d]\n",
> +		 err_injected, xe->inject_driver_probe_error, func, line);
> +
> +	xe_modparam.inject_driver_probe_error = 0;
> +	return err_injected;
> +}
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index 2c96f1b2aafd..0d0187819e92 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -184,4 +184,27 @@ void xe_device_declare_wedged(struct xe_device *xe);
>  struct xe_file *xe_file_get(struct xe_file *xef);
>  void xe_file_put(struct xe_file *xef);
>  
> +#define XE_DEVICE_INJECTED_ERR -ENODEV
> +#define xe_device_inject_driver_probe_error(__xe) \
> +	__xe_device_inject_driver_probe_error(__xe, XE_DEVICE_INJECTED_ERR, 0, __func__, __LINE__)
> +#define xe_device_inject_driver_probe_error_override(__xe, __err_real) \
> +	__xe_device_inject_driver_probe_error(__xe, XE_DEVICE_INJECTED_ERR, __err_real, __func__, \
> +					      __LINE__)
> +
> +#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> +
> +int __xe_device_inject_driver_probe_error(struct xe_device *xe,
> +					  int err_injected, int err_real,
> +					  const char *func, int line);
> +#else
> +
> +static inline int __xe_device_inject_driver_probe_error(struct xe_device *xe,
> +							int err_injected, int err_real,
> +							const char *func, int line)
> +{
> +	return 0;
> +}
> +
> +#endif
> +
>  #endif
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 16a24eadd94b..5097376aec28 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -491,6 +491,11 @@ struct xe_device {
>  		int mode;
>  	} wedged;
>  
> +#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> +	/** @inject_driver_probe_error: Counter used for error injection during probe */
> +	int inject_driver_probe_error;
> +#endif
> +
>  #ifdef TEST_VM_OPS_ERROR
>  	/**
>  	 * @vm_inject_error_position: inject errors at different places in VM
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index 58895ed22f6e..b90acc7eedba 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -378,6 +378,7 @@ int xe_gt_init_early(struct xe_gt *gt)
>  	xe_reg_sr_init(&gt->reg_sr, "GT", gt_to_xe(gt));
>  
>  	err = xe_wa_init(gt);
> +	err = xe_device_inject_driver_probe_error_override(gt_to_xe(gt), err);
>  	if (err)
>  		return err;
>  
> @@ -564,6 +565,7 @@ int xe_gt_init_hwconfig(struct xe_gt *gt)
>  		goto out_fw;
>  
>  	err = xe_uc_init_hwconfig(&gt->uc);
> +	err = xe_device_inject_driver_probe_error_override(gt_to_xe(gt), err);
>  	if (err)
>  		goto out_fw;
>  
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> index ef239440963c..09e1fe745ada 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> @@ -7,6 +7,7 @@
>  
>  #include "regs/xe_regs.h"
>  
> +#include "xe_device.h"
>  #include "xe_gt_sriov_pf.h"
>  #include "xe_gt_sriov_pf_config.h"
>  #include "xe_gt_sriov_pf_helpers.h"
> @@ -54,6 +55,7 @@ int xe_gt_sriov_pf_init_early(struct xe_gt *gt)
>  		return err;
>  
>  	err = xe_gt_sriov_pf_service_init(gt);
> +	err = xe_device_inject_driver_probe_error_override(gt_to_xe(gt), err);
>  	if (err)
>  		return err;
>  
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index de0fe9e65746..74e598294f90 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -351,6 +351,7 @@ int xe_guc_init(struct xe_guc *guc)
>  		goto out;
>  
>  	ret = devm_add_action_or_reset(xe->drm.dev, guc_fini_hw, guc);
> +	ret = xe_device_inject_driver_probe_error_override(guc_to_xe(guc), ret);
>  	if (ret)
>  		goto out;
>  
> @@ -408,6 +409,7 @@ int xe_guc_init_post_hwconfig(struct xe_guc *guc)
>  		return ret;
>  
>  	ret = xe_guc_pc_init(&guc->pc);
> +	ret = xe_device_inject_driver_probe_error_override(guc_to_xe(guc), ret);
>  	if (ret)
>  		return ret;
>  
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index beeeb120d1fc..ed715a252f6a 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -194,6 +194,7 @@ int xe_guc_ct_init(struct xe_guc_ct *ct)
>  	ct->bo = bo;
>  
>  	err = drmm_add_action_or_reset(&xe->drm, guc_ct_fini, ct);
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (err)
>  		return err;
>  
> diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
> index bdcc7282385c..af322f5c8159 100644
> --- a/drivers/gpu/drm/xe/xe_mmio.c
> +++ b/drivers/gpu/drm/xe/xe_mmio.c
> @@ -136,6 +136,11 @@ int xe_mmio_probe_tiles(struct xe_device *xe)
>  {
>  	size_t tile_mmio_size = SZ_16M;
>  	size_t tile_mmio_ext_size = xe->info.tile_mmio_ext_size;
> +	int err;
> +
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
>  
>  	mmio_multi_tile_setup(xe, tile_mmio_size);
>  	mmio_extension_setup(xe, tile_mmio_size, tile_mmio_ext_size);
> diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
> index 923460119cec..806b6c1f8a7f 100644
> --- a/drivers/gpu/drm/xe/xe_module.c
> +++ b/drivers/gpu/drm/xe/xe_module.c
> @@ -53,6 +53,11 @@ module_param_named_unsafe(force_probe, xe_modparam.force_probe, charp, 0400);
>  MODULE_PARM_DESC(force_probe,
>  		 "Force probe options for specified devices. See CONFIG_DRM_XE_FORCE_PROBE for details.");
>  
> +#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> +module_param_named_unsafe(inject_driver_probe_error, xe_modparam.inject_driver_probe_error, int, 0600);
> +MODULE_PARM_DESC(inject_driver_probe_error, "Inject driver probe error");
> +#endif
> +
>  #ifdef CONFIG_PCI_IOV
>  module_param_named(max_vfs, xe_modparam.max_vfs, uint, 0400);
>  MODULE_PARM_DESC(max_vfs,
> diff --git a/drivers/gpu/drm/xe/xe_module.h b/drivers/gpu/drm/xe/xe_module.h
> index 161a5e6f717f..47cefaf8d79b 100644
> --- a/drivers/gpu/drm/xe/xe_module.h
> +++ b/drivers/gpu/drm/xe/xe_module.h
> @@ -20,6 +20,9 @@ struct xe_modparam {
>  	char *force_probe;
>  #ifdef CONFIG_PCI_IOV
>  	unsigned int max_vfs;
> +#endif
> +#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> +	int inject_driver_probe_error;
>  #endif
>  	int wedged_mode;
>  };
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index 3c34b032ebf4..bac07779d353 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -626,6 +626,7 @@ static int xe_info_init_early(struct xe_device *xe,
>  				 desc->has_display;
>  
>  	err = xe_tile_init_early(xe_device_get_root_tile(xe), xe, 0);
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (err)
>  		return err;
>  
> @@ -645,8 +646,13 @@ static int xe_info_init(struct xe_device *xe,
>  	u32 graphics_gmdid_revid = 0, media_gmdid_revid = 0;
>  	struct xe_tile *tile;
>  	struct xe_gt *gt;
> +	int err;
>  	u8 id;
>  
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
> +
>  	/*
>  	 * If this platform supports GMD_ID, we'll detect the proper IP
>  	 * descriptor to use from hardware registers. desc->graphics will only
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index 9f3c14fd9f33..2de8383b745d 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -228,6 +228,7 @@ int xe_pm_init_early(struct xe_device *xe)
>  		return err;
>  
>  	err = drmm_mutex_init(&xe->drm, &xe->d3cold.lock);
> +	err = xe_device_inject_driver_probe_error_override(xe, err);
>  	if (err)
>  		return err;
>  
> @@ -246,6 +247,10 @@ int xe_pm_init(struct xe_device *xe)
>  {
>  	int err;
>  
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
> +
>  	/* For now suspend/resume is only allowed with GuC */
>  	if (!xe_device_uc_enabled(xe))
>  		return 0;
> diff --git a/drivers/gpu/drm/xe/xe_sriov.c b/drivers/gpu/drm/xe/xe_sriov.c
> index 5a1d65e4f19f..b19b06c72870 100644
> --- a/drivers/gpu/drm/xe/xe_sriov.c
> +++ b/drivers/gpu/drm/xe/xe_sriov.c
> @@ -102,9 +102,15 @@ static void fini_sriov(struct drm_device *drm, void *arg)
>   */
>  int xe_sriov_init(struct xe_device *xe)
>  {
> +	int err;
> +
>  	if (!IS_SRIOV(xe))
>  		return 0;
>  
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
> +
>  	if (IS_SRIOV_PF(xe)) {
>  		int err = xe_sriov_pf_init_early(xe);
>  
> diff --git a/drivers/gpu/drm/xe/xe_tile.c b/drivers/gpu/drm/xe/xe_tile.c
> index 15ea0a942f67..d70f1f61c096 100644
> --- a/drivers/gpu/drm/xe/xe_tile.c
> +++ b/drivers/gpu/drm/xe/xe_tile.c
> @@ -124,6 +124,10 @@ int xe_tile_init_early(struct xe_tile *tile, struct xe_device *xe, u8 id)
>  	if (IS_ERR(tile->primary_gt))
>  		return PTR_ERR(tile->primary_gt);
>  
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> index 0d073a9987c2..0c40fbdf21ee 100644
> --- a/drivers/gpu/drm/xe/xe_uc.c
> +++ b/drivers/gpu/drm/xe/xe_uc.c
> @@ -59,6 +59,7 @@ int xe_uc_init(struct xe_uc *uc)
>  		return 0;
>  
>  	ret = xe_wopcm_init(&uc->wopcm);
> +	ret = xe_device_inject_driver_probe_error_override(uc_to_xe(uc), ret);
>  	if (ret)
>  		goto err;
>  
> diff --git a/drivers/gpu/drm/xe/xe_wa.c b/drivers/gpu/drm/xe/xe_wa.c
> index 28b7f95b6c2f..156a77b27593 100644
> --- a/drivers/gpu/drm/xe/xe_wa.c
> +++ b/drivers/gpu/drm/xe/xe_wa.c
> @@ -825,6 +825,7 @@ int xe_wa_init(struct xe_gt *gt)
>  	struct xe_device *xe = gt_to_xe(gt);
>  	size_t n_oob, n_lrc, n_engine, n_gt, total;
>  	unsigned long *p;
> +	int err;
>  
>  	n_gt = BITS_TO_LONGS(ARRAY_SIZE(gt_was));
>  	n_engine = BITS_TO_LONGS(ARRAY_SIZE(engine_was));
> @@ -836,6 +837,10 @@ int xe_wa_init(struct xe_gt *gt)
>  	if (!p)
>  		return -ENOMEM;
>  
> +	err = xe_device_inject_driver_probe_error(xe);
> +	if (err)
> +		return err;
> +
>  	gt->wa_active.gt = p;
>  	p += n_gt;
>  	gt->wa_active.engine = p;
> diff --git a/drivers/gpu/drm/xe/xe_wopcm.c b/drivers/gpu/drm/xe/xe_wopcm.c
> index d3a99157e523..c9be9d31d3ae 100644
> --- a/drivers/gpu/drm/xe/xe_wopcm.c
> +++ b/drivers/gpu/drm/xe/xe_wopcm.c
> @@ -263,6 +263,10 @@ int xe_wopcm_init(struct xe_wopcm *wopcm)
>  		return -E2BIG;
>  	}
>  
> +	ret = xe_device_inject_driver_probe_error(xe);
> +	if (ret)
> +		return ret;
> +
>  	if (!locked)
>  		ret = __wopcm_init_regs(xe, gt, wopcm);

-- 
Jani Nikula, Intel


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