On Monday, September 21, 2026 10:03:02 PM Central European Summer Time James
Zhu wrote:
> Add the DRM_AMDGPU_PROFILER ioctl number and its argument structures, the
> UAPI for GPU performance monitoring features such as SPM (Stream
> Performance Monitor).
>
> struct drm_amdgpu_profiler_args carries an operation selector and a union
> of per-operation parameters, currently AMDGPU_PROFILER_OP_GET_VER and
> AMDGPU_PROFILER_OP_SPM. The SPM operations and the layout of the
> destination buffer are described by struct drm_amdgpu_spm_args and
> struct drm_amdgpu_spm_buffer_header.
>
> The ioctl number and struct layout are frozen here. The implementation
> lands in the rest of this series and the ioctl is not registered in
> amdgpu_ioctls_kms[] until then, so this header change alone does not make
> the interface reachable.
>
> Signed-off-by: James Zhu <[email protected]>
> Reviewed-by: Bing Ma <[email protected]>
Hi,
Can you guys please clarify why this is necessary and what the use case is?
Are we sure we want a uAPI for this? RADV has been using SPM from userspace
for many years now.
Thanks & best regards,
Timur
> ---
> include/uapi/drm/amdgpu_drm.h | 124 ++++++++++++++++++++++++++++++++++
> 1 file changed, 124 insertions(+)
>
> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
> index 9e5fa6f53e59..285949d63eb6 100644
> --- a/include/uapi/drm/amdgpu_drm.h
> +++ b/include/uapi/drm/amdgpu_drm.h
> @@ -60,6 +60,7 @@ extern "C" {
> #define DRM_AMDGPU_GEM_LIST_HANDLES 0x19
> #define DRM_AMDGPU_PROC_OPTIONS 0x1A
> #define DRM_AMDGPU_TRAP 0x1B
> +#define DRM_AMDGPU_PROFILER 0x1C
>
> #define DRM_IOCTL_AMDGPU_GEM_CREATE DRM_IOWR(DRM_COMMAND_BASE +
> DRM_AMDGPU_GEM_CREATE, union drm_amdgpu_gem_create) #define
> DRM_IOCTL_AMDGPU_GEM_MMAP DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_MMAP,
> union drm_amdgpu_gem_mmap) @@ -83,6 +84,7 @@ extern "C" {
> #define DRM_IOCTL_AMDGPU_GEM_LIST_HANDLES DRM_IOWR(DRM_COMMAND_BASE +
> DRM_AMDGPU_GEM_LIST_HANDLES, struct drm_amdgpu_gem_list_handles) #define
> DRM_IOCTL_AMDGPU_PROC_OPTIONS DRM_IOWR(DRM_COMMAND_BASE +
> DRM_AMDGPU_PROC_OPTIONS, struct drm_amdgpu_proc_options) #define
> DRM_IOCTL_AMDGPU_TRAP DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_TRAP,
union
> drm_amdgpu_trap) +#define
> DRM_IOCTL_AMDGPU_PROFILER DRM_IOWR(DRM_COMMAND_BASE +
DRM_AMDGPU_PROFILER,
> struct drm_amdgpu_profiler_args)
>
> /**
> * DOC: memory domains
> @@ -1821,6 +1823,128 @@ struct drm_amdgpu_proc_options {
> } kfd_sigbus_delay;
> };
>
> +/*
> + * Supported SPM (Stream Performance Monitor) Operations
> + */
> +/**
> + * drm_amdgpu_spm_op - SPM ioctl operations
> + */
> +enum drm_amdgpu_spm_op {
> + AMDGPU_SPM_OP_ACQUIRE = 1,
> + AMDGPU_SPM_OP_RELEASE,
> + AMDGPU_SPM_OP_SET_DEST_BUF
> +};
> +
> +/**
> + * drm_amdgpu_spm_args - Arguments for SPM ioctl
> + *
> + * @dest_buf: [in] used for the address of the destination buffer
> + * in @AMDGPU_SPM_OP_SET_DEST_BUF
> + * @buf_size: [in] size of the destination buffer
> + * @op: [in] specifies the operation to perform
> + * @timeout: [in/out] timeout in milliseconds (in), amount of time left
> + * in the timeout window (out)
> + * @bytes_copied: [out] total amount of data that was copied to the
> previous dest_buf + * @has_data_loss: [out] non-zero if data was lost (e.g.
> due to ring buffer overflow), + * zero otherwise
> + * @reserved: must be zero for forward compatibility
> + *
> + * This ioctl performs different functions depending on the @op parameter.
> + *
> + * AMDGPU_SPM_OP_ACQUIRE
> + * ------------------------
> + *
> + * Acquires exclusive access of SPM on the specified XCP for the calling
> process. + * This must be called before using AMDGPU_SPM_OP_SET_DEST_BUF.
> + *
> + * AMDGPU_SPM_OP_RELEASE
> + * ------------------------
> + *
> + * Releases exclusive access of SPM on the specified XCP for the calling
> process, + * which allows another process to acquire it in the future.
> + *
> + * AMDGPU_SPM_OP_SET_DEST_BUF
> + * -----------------------------
> + *
> + * If @dest_buf is NULL, the destination buffer address is unset and
> copying of counters + * is stopped.
> + *
> + * If @dest_buf is not NULL, it specifies the pointer to a new destination
> buffer. + * @buf_size specifies the size of the buffer.
> + *
> + * If @timeout is non-0, the call will wait for up to @timeout ms for the
> previous + * buffer to be filled. If the previous buffer is filled before
> the timeout, @timeout + * is updated with the time remaining. If the
> timeout is exceeded, the function + * copies any partial data available
> into the previous user buffer and returns success. + * The amount of valid
> data in the previous user buffer is indicated by @bytes_copied. + *
> + * If @timeout is 0, the function immediately replaces the previous
> destination buffer + * without waiting for the previous buffer to be
> filled. That means the previous buffer + * may only be partially filled,
> and @bytes_copied will indicate how much data has been + * copied to it.
> + *
> + * If data was lost, e.g. due to a ring buffer overflow, @has_data_loss
> will be non-0. + *
> + * Returns negative error code on failure, 0 on success.
> + */
> +struct drm_amdgpu_spm_args {
> + __u64 dest_buf;
> + __u32 buf_size;
> + __u32 op;
> + __u32 timeout;
> + __u32 bytes_copied;
> + __u32 has_data_loss;
> + __u32 reserved[9]; /* must be zero; pads this struct to 64
bytes */
> +};
> +
> +/**
> + * drm_amdgpu_spm_buffer_header - SPM Buffer header for
> drm_amdgpu_spm_args->dest_buf + *
> + * @version: [out] SPM version (0-23: minor, 24-31: major)
> + * @bytes_copied: [out] Amount of data copied for this sub-block
> + * @has_data_loss: [out] Boolean indicating whether data was lost for this
> sub-block + * (e.g. due to a ring-buffer overflow)
> + * @reserved: Reserved for future use, must be zero
> + *
> + * This header precedes the SPM data in the destination buffer. The
> reserved + * field maintains 64-byte cache line alignment (32 bytes total).
> + */
> +struct drm_amdgpu_spm_buffer_header {
> + __u32 version; /* 0-23: minor, 24-31: major */
> + __u32 bytes_copied;
> + __u32 has_data_loss;
> + __u32 reserved[5]; /* pad to 32 bytes (64-byte cache line / 2) */
> +};
> +
> +/* Supported Profiler Operation */
> +#define AMDGPU_PROFILER_OP_GET_VER 1 /* get profiler UAPI
version */
> +#define AMDGPU_PROFILER_OP_SPM 2
> +
> +/*
> + * Profiler IOCTL
> + */
> +/**
> + * struct drm_amdgpu_profiler_args - Profiler IOCTL arguments
> + * @op: Operation to perform (AMDGPU_PROFILER_OP_*)
> + * @pad: Must be zero for input validation
> + * @data: Operation-specific parameters (union)
> + *
> + * GET_VER operation:
> + * Returns the profiler UAPI version in @data.version as (MAJOR<<24) |
> MINOR. + * Input: @data must be zero (reserved for forward compatibility).
> + *
> + * Design note: GET_VER is intentionally a parameter-free query returning
> + * the global profiler UAPI version.
> + */
> +struct drm_amdgpu_profiler_args {
> + __u32 op; /*
AMDGPU_PROFILER_OP_* */
> + __u32 pad; /* must be zero */
> + union {
> + __u32 version; /* GET_VER: out
(MAJOR<<24) | MINOR */
> + struct drm_amdgpu_spm_args spm;
> + } data;
> +};
> +
> #if defined(__cplusplus)
> }
> #endif
