struct xensnd_open_req {
	uint32_t                   pcm_rate;             /*     0     4 */
	uint8_t                    pcm_format;           /*     4     1 */
	uint8_t                    pcm_channels;         /*     5     1 */
	uint16_t                   reserved;             /*     6     2 */
	uint32_t                   buffer_sz;            /*     8     4 */
	grant_ref_t                gref_directory_start; /*    12     4 */

	/* size: 16, cachelines: 1, members: 6 */
	/* last cacheline: 16 bytes */
};
struct xensnd_page_directory {
	grant_ref_t                gref_dir_next_page;   /*     0     4 */
	grant_ref_t                gref[1];              /*     4     4 */

	/* size: 8, cachelines: 1, members: 2 */
	/* last cacheline: 8 bytes */
};
struct xensnd_rw_req {
	uint32_t                   offset;               /*     0     4 */
	uint32_t                   len;                  /*     4     4 */

	/* size: 8, cachelines: 1, members: 2 */
	/* last cacheline: 8 bytes */
};
struct xensnd_req {
	uint16_t                   id;                   /*     0     2 */
	uint8_t                    operation;            /*     2     1 */
	uint8_t                    reserved[5];          /*     3     5 */
	union {
		struct xensnd_open_req open;             /*          16 */
		struct xensnd_rw_req rw;                 /*           8 */
		uint8_t            reserved[24];         /*          24 */
	} op;                                            /*     8    24 */

	/* size: 32, cachelines: 1, members: 4 */
	/* last cacheline: 32 bytes */
};
struct xensnd_resp {
	uint16_t                   id;                   /*     0     2 */
	uint8_t                    operation;            /*     2     1 */
	uint8_t                    reserved;             /*     3     1 */
	int32_t                    status;               /*     4     4 */
	uint8_t                    reserved1[24];        /*     8    24 */

	/* size: 32, cachelines: 1, members: 5 */
	/* last cacheline: 32 bytes */
};