On Wed, April 23, 2025 7:15 PM Brost, Matthew wrote:
> On Wed, Apr 23, 2025 at 07:57:10PM -0600, Lin, Shuicheng wrote:
> > On Wed, April 23, 2025 1:19 PM Cavitt, Jonathan wrote:
> > > Add initial declarations for the drm_xe_vm_get_property ioctl.
> > >
> > > v2:
> > > - Expand kernel docs for drm_xe_vm_get_property (Jianxun)
> > >
> > > v3:
> > > - Remove address type external definitions (Jianxun)
> > > - Add fault type to xe_drm_fault struct (Jianxun)
> > >
> > > v4:
> > > - Remove engine class and instance (Ivan)
> > >
> > > v5:
> > > - Add declares for fault type, access type, and fault level (Matt Brost,
> > > Ivan)
> > >
> > > v6:
> > > - Fix inconsistent use of whitespace in defines
> > >
> > > Signed-off-by: Jonathan Cavitt <jonathan.cav...@intel.com>
> > > Cc: Zhang Jianxun <jianxun.zh...@intel.com>
> > > Cc: Ivan Briano <ivan.bri...@intel.com>
> > > Cc: Matthew Brost <matthew.br...@intel.com>
> > > ---
LGTM.
Reviewed-by: Shuicheng Lin <shuicheng....@intel.com>
> > > include/uapi/drm/xe_drm.h | 86
> > > +++++++++++++++++++++++++++++++++++++++
> > > 1 file changed, 86 insertions(+)
> > >
> > > diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> > > index
> > > 9c08738c3b91..556fc360a076 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_PROPERTY
> > > */
> > >
> > > /*
> > > @@ -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_PROPERTY 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_PROPERTY
> > > DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_VM_GET_PROPERTY,
> struct
> > > drm_xe_vm_get_property)
> > >
> > > /**
> > > * DOC: Xe IOCTL Extensions
> > > @@ -1193,6 +1196,89 @@ struct drm_xe_vm_bind {
> > > __u64 reserved[2];
> > > };
> > >
> > > +/** struct xe_vm_fault - Describes faults for
> > > +%DRM_XE_VM_GET_PROPERTY_FAULTS */ struct xe_vm_fault {
> > > + /** @address: Address of the fault */
> > > + __u64 address;
> > > + /** @address_precision: Precision of faulted address */
> > > + __u32 address_precision;
> > > + /** @access_type: Type of address access that resulted in fault */
> > > +#define FAULT_ACCESS_TYPE_READ 0
> > > +#define FAULT_ACCESS_TYPE_WRITE 1
> > > +#define FAULT_ACCESS_TYPE_ATOMIC 2
> >
> > There is the same definition of "FLT_ACCESS_TYPE_READ" in the
> "regs/xe_pagefault_desc.h"
> > Could we remove the definition in xe_pagefault_desc.h, and change to this
> definition?
> > Also for the access_type in below.
> >
>
> No — I'm getting a little frustrated here.
>
> I've explained this multiple times, both in the comments on the list and in
> our
> internal Teams chat. The uAPI is an abstraction of the hardware — it is not a
> direct interface to hardware-reported values in user space.
>
> The reason for this is simple: if the underlying hardware changes, a direct
> interface would break the uAPI. Right now, the values may happen to match,
> but there’s no guarantee they will continue to do so in the future.
>
> Please, everyone, stop bringing this up.
>
> Matt
OK. Get it. Thanks.
Shuicheng
>
> > Shuicheng
> >
> > > + __u8 access_type;
> > > + /** @fault_type: Type of fault reported */
> > > +#define FAULT_TYPE_NOT_PRESENT 0
> > > +#define FAULT_TYPE_WRITE_ACCESS 1
> > > +#define FAULT_TYPE_ATOMIC_ACCESS 2
> > > + __u8 fault_type;
> > > + /** @fault_level: fault level of the fault */
> > > +#define FAULT_LEVEL_PTE 0
> > > +#define FAULT_LEVEL_PDE 1
> > > +#define FAULT_LEVEL_PDP 2
> > > +#define FAULT_LEVEL_PML4 3
> > > +#define FAULT_LEVEL_PML5 4
> > > + __u8 fault_level;
> > > + /** @pad: MBZ */
> > > + __u8 pad;
> > > + /** @reserved: MBZ */
> > > + __u64 reserved[4];
> > > +};
> > > +
> > > +/**
> > > + * struct drm_xe_vm_get_property - Input of
> > > +&DRM_IOCTL_XE_VM_GET_PROPERTY
> > > + *
> > > + * The user provides a VM and a property to query among
> > > +DRM_XE_VM_GET_PROPERTY_*,
> > > + * and sets the values in the vm_id and property members, respectively.
> > > +This
> > > + * determines both the VM to get the property of, as well as the
> > > +property to
> > > + * report.
> > > + *
> > > + * If size is set to 0, the driver fills it with the required size
> > > +for the
> > > + * requested property. The user is expected here to allocate
> > > +memory for the
> > > + * property structure and to provide a pointer to the allocated
> > > +memory using the
> > > + * data member. For some properties, this may be zero, in which
> > > +case, the
> > > + * value of the property will be saved to the value member and size
> > > +will remain
> > > + * zero on return.
> > > + *
> > > + * If size is not zero, then the IOCTL will attempt to copy the
> > > +requested
> > > + * property into the data member.
> > > + *
> > > + * The IOCTL will return -ENOENT if the VM could not be identified
> > > +from the
> > > + * provided VM ID, or -EINVAL if the IOCTL fails for any other
> > > +reason, such as
> > > + * providing an invalid size for the given property or if the
> > > +property data
> > > + * could not be copied to the memory allocated to the data member.
> > > + *
> > > + * The property member can be:
> > > + * - %DRM_XE_VM_GET_PROPERTY_FAULTS */ struct
> > > +drm_xe_vm_get_property {
> > > + /** @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;
> > > +
> > > +#define DRM_XE_VM_GET_PROPERTY_FAULTS 0
> > > + /** @property: property to get */
> > > + __u32 property;
> > > +
> > > + /** @size: Size to allocate for @data */
> > > + __u32 size;
> > > +
> > > + /** @pad: MBZ */
> > > + __u32 pad;
> > > +
> > > + union {
> > > + /** @data: Pointer to user-defined array of flexible size and
> > > type */
> > > + __u64 data;
> > > + /** @value: Return value for scalar queries */
> > > + __u64 value;
> > > + };
> > > +
> > > + /** @reserved: MBZ */
> > > + __u64 reserved[3];
> > > +};
> > > +
> > > /**
> > > * struct drm_xe_exec_queue_create - Input of
> > > &DRM_IOCTL_XE_EXEC_QUEUE_CREATE
> > > *
> > > --
> > > 2.43.0
> >
