-----Original Message-----
From: Brost, Matthew <matthew.brost@xxxxxxxxx>
Sent: Monday, March 10, 2025 9:51 PM
To: Cavitt, Jonathan <jonathan.cavitt@xxxxxxxxx>
Cc: intel-xe@xxxxxxxxxxxxxxxxxxxxx; Gupta, saurabhg <saurabhg.gupta@xxxxxxxxx>; Zuo, Alex <alex.zuo@xxxxxxxxx>; joonas.lahtinen@xxxxxxxxxxxxxxx; Zhang, Jianxun <jianxun.zhang@xxxxxxxxx>; Lin, Shuicheng <shuicheng.lin@xxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx
Subject: Re: [PATCH v7 4/6] drm/xe/uapi: Define drm_xe_vm_get_faults
>
> On Mon, Mar 10, 2025 at 05:18:32PM +0000, Jonathan Cavitt wrote:
> > Add initial declarations for the drm_xe_vm_get_faults ioctl.
> >
> > Signed-off-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> > ---
> > include/uapi/drm/xe_drm.h | 49 +++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 49 insertions(+)
> >
> > diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> > index 616916985e3f..90c2fcdbd5c1 100644
> > --- a/include/uapi/drm/xe_drm.h
> > +++ b/include/uapi/drm/xe_drm.h
> > @@ -81,6 +81,7 @@ extern "C" {
> > * - &DRM_IOCTL_XE_EXEC
> > * - &DRM_IOCTL_XE_WAIT_USER_FENCE
> > * - &DRM_IOCTL_XE_OBSERVATION
> > + * - %DRM_IOCTL_XE_VM_GET_FAULTS
>
> This should be a generic "get VM property" IOCTL, not a specific IOCTL
> that only retrieves faults. This allows for future expansion of the
> uAPI.
Question from @Zhang, Jianxun :
"""
But first of all, should we regard faults as a property?
"""
-Jonathan Cavitt
>
> > */
> >
> > /*
> > @@ -102,6 +103,7 @@ extern "C" {
> > #define DRM_XE_EXEC 0x09
> > #define DRM_XE_WAIT_USER_FENCE 0x0a
> > #define DRM_XE_OBSERVATION 0x0b
> > +#define DRM_XE_VM_GET_FAULTS 0x0c
> >
> > /* Must be kept compact -- no holes */
> >
> > @@ -117,6 +119,7 @@ extern "C" {
> > #define DRM_IOCTL_XE_EXEC DRM_IOW(DRM_COMMAND_BASE + DRM_XE_EXEC, struct drm_xe_exec)
> > #define DRM_IOCTL_XE_WAIT_USER_FENCE DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_WAIT_USER_FENCE, struct drm_xe_wait_user_fence)
> > #define DRM_IOCTL_XE_OBSERVATION DRM_IOW(DRM_COMMAND_BASE + DRM_XE_OBSERVATION, struct drm_xe_observation_param)
> > +#define DRM_IOCTL_XE_VM_GET_FAULTS DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_VM_GET_FAULTS, struct drm_xe_vm_get_faults)
> >
> > /**
> > * DOC: Xe IOCTL Extensions
> > @@ -1189,6 +1192,52 @@ struct drm_xe_vm_bind {
> > __u64 reserved[2];
> > };
> >
> > +struct xe_vm_fault {
> > + /** @address: Address of the fault, if relevant */
> > + __u64 address;
> > +#define DRM_XE_FAULT_ADDRESS_TYPE_NONE_EXT 0
> > +#define DRM_XE_FAULT_ADDRESS_TYPE_READ_INVALID_EXT 1
> > +#define DRM_XE_FAULT_ADDRESS_TYPE_WRITE_INVALID_EXT 2
> > + /** @address_type: , if relevant */
> > + __u32 address_type;
> > + /**
> > + * @address_precision: Precision of faulted address, if relevant.
> > + * Currently only SZ_4K.
> > + */
> > + __u32 address_precision;
> > + /** @reserved: MBZ */
> > + __u64 reserved[3];
> > +};
> > +
> > +/**
> > + * struct drm_xe_vm_get_faults - Input of &DRM_IOCTL_XE_VM_GET_FAULTS
> > + *
> > + * The user provides a VM ID, and the ioctl will
> > + *
> > + */
> > +struct drm_xe_vm_get_faults {
> > + /** @extensions: Pointer to the first extension struct, if any */
> > + __u64 extensions;
> > +
> > + /** @vm_id: The ID of the VM to query the properties of */
> > + __u32 vm_id;
> > +
> > + /** @size: Size to allocate for @ptr */
> > + __u32 size;
> > +
> > + /** @fault_count: Number of faults to be returned */
> > + __u32 fault_count;
> > +
>
> fault_count is implied by size.
>
> Matt
>
> > + /** @pad: MBZ */
> > + __u32 pad;
> > +
> > + /** @reserved: MBZ */
> > + __u64 reserved[2];
> > +
> > + /** @faults: Pointer to user-defined array of xe_vm_fault of flexible size */
> > + __u64 faults;
> > +};
> > +
> > /**
> > * struct drm_xe_exec_queue_create - Input of &DRM_IOCTL_XE_EXEC_QUEUE_CREATE
> > *
> > --
> > 2.43.0
> >
>
