[PATCH RFC 7/8] nvme: Add Controller Data Queue (CDQ) ioctl command

From: Joel Granados
Date: Mon Jul 14 2025 - 05:17:43 EST


New ioctl to create a CDQ.

Creating a CDQ:
Set the following memebers:
* entry_nr: Number of CDQ entries
* entry_nbytes: size in bytes of each CDQ entry
* cqs: Create Queue Specific. Value depends on CDQ type
* mos: Management Operation Specific. Value depends on CDQ type
* cdqp_{offset,mask}: Location of CDQ Phase tag bit within an entry

Return:
* cdq_id: The ID set by the controller for the created CDQ
* read_fd: The file descriptor that can be used to read the CDQ

Signed-off-by: Joel Granados <joel.granados@xxxxxxxxxx>
---
include/uapi/linux/nvme_ioctl.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index 2f76cba6716637baff53e167a6141b68420d75c3..dc434628acc8462877e774a1eec9242a5df8a08a 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -92,6 +92,17 @@ struct nvme_uring_cmd {
__u32 rsvd2;
};

+struct nvme_cdq_cmd {
+ __u32 entry_nr;
+ __u32 entry_nbyte;
+ __u16 cdq_id;
+ __u16 cqs;
+ __u16 mos;
+ __u32 cdqp_offset;
+ __u32 cdqp_mask;
+ int read_fd;
+};
+
#define nvme_admin_cmd nvme_passthru_cmd

#define NVME_IOCTL_ID _IO('N', 0x40)
@@ -104,6 +115,7 @@ struct nvme_uring_cmd {
#define NVME_IOCTL_ADMIN64_CMD _IOWR('N', 0x47, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD _IOWR('N', 0x48, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD_VEC _IOWR('N', 0x49, struct nvme_passthru_cmd64)
+#define NVME_IOCTL_ADMIN_CDQ _IOR('N', 0x50, struct nvme_cdq_cmd)

/* io_uring async commands: */
#define NVME_URING_CMD_IO _IOWR('N', 0x80, struct nvme_uring_cmd)

--
2.47.2