Re: [PATCH v4 32/33] drm/xe: Add always_migrate_to_vram modparam

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Wed, 2025-01-29 at 11:52 -0800, Matthew Brost wrote:
> Used to show we can bounce memory multiple times which will happen
> once
> a real migration policy is implemented. Can be removed once migration
> policy is implemented.
> 
> v3:
>  - Pull some changes into the previous patch (Thomas)
>  - Spell out power of 2 (Thomas)
>  - Better commit message (Thomas)
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_module.c | 5 ++++-
>  drivers/gpu/drm/xe/xe_module.h | 1 +
>  drivers/gpu/drm/xe/xe_svm.c    | 3 +++
>  3 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_module.c
> b/drivers/gpu/drm/xe/xe_module.c
> index 2126e99ede01..192047b3419b 100644
> --- a/drivers/gpu/drm/xe/xe_module.c
> +++ b/drivers/gpu/drm/xe/xe_module.c
> @@ -30,7 +30,10 @@ struct xe_modparam xe_modparam = {
>  };
>  
>  module_param_named(svm_notifier_size, xe_modparam.svm_notifier_size,
> uint, 0600);
> -MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size(in
> MiB), must be pow2");
> +MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size(in
> MiB), must be power of 2");
> +

This should've really been in previous patch?

With that fixed,
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

> +module_param_named(always_migrate_to_vram,
> xe_modparam.always_migrate_to_vram, bool, 0444);
> +MODULE_PARM_DESC(always_migrate_to_vram, "Always migrate to VRAM on
> GPU fault");
>  
>  module_param_named_unsafe(force_execlist,
> xe_modparam.force_execlist, bool, 0444);
>  MODULE_PARM_DESC(force_execlist, "Force Execlist submission");
> diff --git a/drivers/gpu/drm/xe/xe_module.h
> b/drivers/gpu/drm/xe/xe_module.h
> index 5a3bfea8b7b4..84339e509c80 100644
> --- a/drivers/gpu/drm/xe/xe_module.h
> +++ b/drivers/gpu/drm/xe/xe_module.h
> @@ -12,6 +12,7 @@
>  struct xe_modparam {
>  	bool force_execlist;
>  	bool probe_display;
> +	bool always_migrate_to_vram;
>  	u32 force_vram_bar_size;
>  	int guc_log_level;
>  	char *guc_firmware_path;
> diff --git a/drivers/gpu/drm/xe/xe_svm.c
> b/drivers/gpu/drm/xe/xe_svm.c
> index f291b2eb2073..a96b0afc0e31 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -821,6 +821,9 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> struct xe_vma *vma,
>  	}
>  	drm_exec_fini(&exec);
>  
> +	if (xe_modparam.always_migrate_to_vram)
> +		range->migrated = false;
> +
>  	dma_fence_wait(fence, false);
>  	dma_fence_put(fence);
>