[PATCH i-g-t v2 1/2] lib/xe/xe_query: return errno from xe_supports_faults check

[Kamil Konieczny]

Hi Jonathan,
On 2024-05-10 at 11:24:37 -0700, Jonathan Cavitt wrote:
> Return the exact error value from the ioctl used in xe_supports_faults.
> This is done because it is possible that faults are supported on the
> system but are temporarily unavailable due to VM usage.  This change
> allows the user to determine if they are willing to wait for fault
> support to become active again.
> 
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

> ---
>  lib/xe/xe_query.c | 15 ++++++++-------
>  lib/xe/xe_query.h |  2 +-
>  2 files changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/xe/xe_query.c b/lib/xe/xe_query.c
> index 6df8f42649..145dee8142 100644
> --- a/lib/xe/xe_query.c
> +++ b/lib/xe/xe_query.c
> @@ -300,27 +300,28 @@ void xe_device_put(int fd)
>   * xe_supports_faults:
>   * @fd: xe device fd
>   *
> - * Returns true if xe device @fd allows creating vm in fault mode otherwise
> - * false.
> + * Returns the return value of the ioctl.  This can either be 0 if the
> + * xe device @fd allows creating a vm in fault mode, or an error value
> + * if it does not.
>   *
>   * NOTE: This function temporarily creates a VM in fault mode. Hence, while
>   * this function is executing, no non-fault mode VMs can be created.
>   */
> -bool xe_supports_faults(int fd)
> +int xe_supports_faults(int fd)
>  {
> -	bool supports_faults;
> +	int ret;
>  
>  	struct drm_xe_vm_create create = {
>  		.flags = DRM_XE_VM_CREATE_FLAG_LR_MODE |
>  			 DRM_XE_VM_CREATE_FLAG_FAULT_MODE,
>  	};
>  
> -	supports_faults = !igt_ioctl(fd, DRM_IOCTL_XE_VM_CREATE, &create);
> +	ret = igt_ioctl(fd, DRM_IOCTL_XE_VM_CREATE, &create);
>  
> -	if (supports_faults)
> +	if (!ret)
>  		xe_vm_destroy(fd, create.vm_id);
>  
> -	return supports_faults;
> +	return ret;
>  }
>  
>  static void xe_device_destroy_cache(void)
> diff --git a/lib/xe/xe_query.h b/lib/xe/xe_query.h
> index f91d16bdf5..54115f8f7c 100644
> --- a/lib/xe/xe_query.h
> +++ b/lib/xe/xe_query.h
> @@ -94,7 +94,7 @@ uint64_t xe_visible_available_vram_size(int fd, int gt);
>  uint32_t xe_get_default_alignment(int fd);
>  uint32_t xe_va_bits(int fd);
>  uint16_t xe_dev_id(int fd);
> -bool xe_supports_faults(int fd);
> +int xe_supports_faults(int fd);
>  const char *xe_engine_class_string(uint32_t engine_class);
>  bool xe_has_engine_class(int fd, uint16_t engine_class);
>  bool xe_has_media_gt(int fd);
> -- 
> 2.25.1
>