[PATCH v4 02/20] drm/xe/uapi: Add madvise interface
Ghimiray, Himal Prasad
himal.prasad.ghimiray at intel.com
Mon Jun 23 06:20:21 UTC 2025
On 23-06-2025 10:00, Matthew Brost wrote:
> On Fri, Jun 13, 2025 at 06:25:40PM +0530, Himal Prasad Ghimiray wrote:
>> This commit introduces a new madvise interface to support
>> driver-specific ioctl operations. The madvise interface allows for more
>> efficient memory management by providing hints to the driver about the
>> expected memory usage and pte update policy for gpuvma.
>>
>> v2 (Matthew/Thomas)
>> - Drop num_ops support
>> - Drop purgeable support
>> - Add kernel-docs
>> - IOWR/IOW
>>
>> Cc: Matthew Brost <matthew.brost at intel.com>
>> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
>> Acked-by: José Roberto de Souza <jose.souza at intel.com>
>> ---
>> include/uapi/drm/xe_drm.h | 118 ++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 118 insertions(+)
>>
>> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
>> index 6a702ba7817c..b5f8d11faaa8 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_MADVISE
>> */
>>
>> /*
>> @@ -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_MADVISE 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_MADVISE DRM_IOW(DRM_COMMAND_BASE + DRM_XE_MADVISE, struct drm_xe_madvise)
>>
>> /**
>> * DOC: Xe IOCTL Extensions
>> @@ -1970,6 +1973,121 @@ struct drm_xe_query_eu_stall {
>> __u64 sampling_rates[];
>> };
>>
>> +/**
>> + * struct drm_xe_madvise - Input of &DRM_IOCTL_XE_MADVISE
>> + *
>> + * This structure is used to set memory attributes for a virtual address range
>> + * in a VM. The type of attribute is specified by @type, and the corresponding
>> + * union member is used to provide additional parameters for @type.
>> + *
>> + * Supported attribute types:
>> + * - DRM_XE_VMA_ATTR_PREFERRED_LOC: Set preferred memory location.
>> + * - DRM_XE_VMA_ATTR_ATOMIC: Set atomic access policy.
>> + * - DRM_XE_VMA_ATTR_PAT: Set page attribute table index.
>> + *
>> + * Example:
>> + *
>> + * .. code-block:: C
>> + *
>> + * struct drm_xe_madvise madvise = {
>> + * .vm_id = vm_id,
>> + * .start = 0x100000,
>> + * .range = 0x2000,
>> + * .type = DRM_XE_VMA_ATTR_ATOMIC,
>> + * .atomic_val = DRM_XE_VMA_ATOMIC_DEVICE,
>> + * };
>> + *
>> + * ioctl(fd, DRM_IOCTL_XE_MADVISE, &madvise);
>> + *
>> + */
>> +struct drm_xe_madvise {
>> + /** @extensions: Pointer to the first extension struct, if any */
>> + __u64 extensions;
>> +
>> + /** @start: start of the virtual address range */
>> + __u64 start;
>> +
>> + /** @size: size of the virtual address range */
>> + __u64 range;
>> +
>> + /** @vm_id: vm_id of the virtual range */
>> + __u32 vm_id;
>> +
>> +#define DRM_XE_VMA_ATTR_PREFERRED_LOC 0
>> +#define DRM_XE_VMA_ATTR_ATOMIC 1
>> +#define DRM_XE_VMA_ATTR_PAT 2
>> + /** @type: type of attribute */
>> + __u32 type;
>> +
>> + union {
>
> Nit: I'd make this union is same order as the defines (e.g., preferred location
> first, atomic second, pat third).
sure
>
>> + /**
>> + * @atomic: Atomic access policy
>> + *
>> + * Used when @type == DRM_XE_VMA_ATTR_ATOMIC.
>> + *
>> + * Supported values for @atomic.val:
>> + * - DRM_XE_VMA_ATOMIC_UNDEFINED: Undefined or default behaviour
>> + * Support both GPU and CPU atomic operations for system allocator
>> + * Support GPU atomic operations for normal(bo) allocator
>> + * - DRM_XE_VMA_ATOMIC_DEVICE: Support GPU atomic operations
>> + * - DRM_XE_VMA_ATOMIC_GLOBAL: Support both GPU and CPU atomic operations
>> + * - DRM_XE_VMA_ATOMIC_CPU: Support CPU atomic
>> + */
>> + struct {
>> +#define DRM_XE_VMA_ATOMIC_UNDEFINED 0
>> +#define DRM_XE_VMA_ATOMIC_DEVICE 1
>> +#define DRM_XE_VMA_ATOMIC_GLOBAL 2
>> +#define DRM_XE_VMA_ATOMIC_CPU 3
>> + /** @atomic.val: value of atomic operation */
>> + __u32 val;
>> +
>> + /** @atomic.reserved: Reserved */
>> + __u32 reserved;
>> + } atomic;
>> +
>> + /**
>> + * @pat_index: Page attribute table index
>> + *
>> + * Used when @type == DRM_XE_VMA_ATTR_PAT.
>> + */
>> + struct {
>> + /** @pat_index.val: PAT index value */
>> + __u32 val;
>> +
>> + /** @pat_index.reserved: Reserved */
>> + __u32 reserved;
>> + } pat_index;
>> +
>> + /**
>> + * @preferred_mem_loc: preferred memory location
>> + *
>> + * Used when @type == DRM_XE_VMA_ATTR_PREFERRED_LOC
>> + *
>> + * Supported values for @preferred_mem_loc.devmem_fd:
>> + * - DRM_XE_PREFERRED_LOC_DEFAULT_DEVICE: set vram of faulting tile as preferred loc
>> + * - DRM_XE_PREFERRED_LOC_DEFAULT_SYSTEM: set smem as preferred loc
>> + *
>> + * Supported values for @preferred_mem_loc.migration_policy:
>> + * - DRM_XE_MIGRATE_ALL_PAGES
>> + * - DRM_XE_MIGRATE_ONLY_SYSTEM_PAGES
>> + */
>> + struct {
>> +#define DRM_XE_PREFERRED_LOC_DEFAULT_DEVICE 0
>> +#define DRM_XE_PREFERRED_LOC_DEFAULT_SYSTEM -1
>> + /** @preferred_mem_loc.devmem_fd: fd for preferred loc */
>> + __u32 devmem_fd;
>> +
>> +#define DRM_XE_MIGRATE_ALL_PAGES 0
>> +#define DRM_XE_MIGRATE_ONLY_SYSTEM_PAGES 1
>
> I'd double check with Thomas / maintainers if they want this (migration_policy)
> to be included in this version as still more or less unused in this series.
Sure
>
>> + /** @preferred_mem_loc.migration_policy: Page migration policy */
>> + __u32 migration_policy;
>
> Could we future proof a little, maybe migration_policy is a __u16 (or __u8?) and
> stick a reserved __u16 in here?
OK
>
> Matt
>
>> + } preferred_mem_loc;
>> + };
>> +
>> + /** @reserved: Reserved */
>> + __u64 reserved[2];
>> +};
>> +
>> #if defined(__cplusplus)
>> }
>> #endif
>> --
>> 2.34.1
>>
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