Re: [RFC v1 9/9] drm/xe/vm: Remove restriction that all VMs must be faulting if one is

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Jul 17, 2024 at 03:07:30PM +0200, Francois Dugast wrote:
> With this restriction, all VMs on the device must be faulting VMs
> if there is already one faulting VM, in which case the device is
> considered in fault mode. This prevents for example an application
> from running 3D jobs for the compositor while submitting a SVM
> compute job on the same device.
> 
> Now that mutual exclusion of LR jobs and dma fence jobs is ensured
> on the hw engine group, remove this restriction to allow running
> faulting and non-faulting VMs on the same device.
> 
> Signed-off-by: Francois Dugast <francois.dugast@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.h | 10 ----------
>  drivers/gpu/drm/xe/xe_vm.c     |  8 --------
>  2 files changed, 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index bb07f5669dbb..cb69ecf02c25 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -129,16 +129,6 @@ static inline struct xe_force_wake *gt_to_fw(struct xe_gt *gt)
>  
>  void xe_device_assert_mem_access(struct xe_device *xe);
>  
> -static inline bool xe_device_in_fault_mode(struct xe_device *xe)
> -{
> -	return xe->usm.num_vm_in_fault_mode != 0;
> -}
> -
> -static inline bool xe_device_in_non_fault_mode(struct xe_device *xe)
> -{
> -	return xe->usm.num_vm_in_non_fault_mode != 0;
> -}
> -

These are used in a few other places:

mbrost@lstrano-desk:xe$ grep usm.num_vm_in_ *.c *.h
xe_vm.c:                xe->usm.num_vm_in_fault_mode++;
xe_vm.c:                xe->usm.num_vm_in_non_fault_mode++;
xe_vm.c:                xe->usm.num_vm_in_fault_mode--;
xe_vm.c:                xe->usm.num_vm_in_non_fault_mode--;
xe_device.h:    return xe->usm.num_vm_in_fault_mode != 0;
xe_device.h:    return xe->usm.num_vm_in_non_fault_mode != 0;
xe_device_types.h:              /** @usm.num_vm_in_fault_mode: number of VM in fault mode */
xe_device_types.h:              /** @usm.num_vm_in_non_fault_mode: number of VM in non-fault mode */

Remove this usage everywhere.

Matt

>  static inline bool xe_device_has_flat_ccs(struct xe_device *xe)
>  {
>  	return xe->info.has_flat_ccs;
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index 5b166fa03684..f0d2dc41a25d 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -1875,14 +1875,6 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>  			 args->flags & DRM_XE_VM_CREATE_FLAG_FAULT_MODE))
>  		return -EINVAL;
>  
> -	if (XE_IOCTL_DBG(xe, args->flags & DRM_XE_VM_CREATE_FLAG_FAULT_MODE &&
> -			 xe_device_in_non_fault_mode(xe)))
> -		return -EINVAL;
> -
> -	if (XE_IOCTL_DBG(xe, !(args->flags & DRM_XE_VM_CREATE_FLAG_FAULT_MODE) &&
> -			 xe_device_in_fault_mode(xe)))
> -		return -EINVAL;
> -
>  	if (XE_IOCTL_DBG(xe, args->extensions))
>  		return -EINVAL;
>  
> -- 
> 2.43.0
>