Re: [PATCH liburing v2 3/5] nvme: add nvme opcodes, structures and helper functions

[Jens Axboe <axboe@kernel.dk>]

On 7/26/22 4:52 AM, Ankit Kumar wrote:
> Add bare minimum structures and helper functions required for
> io_uring passthrough commands. This will enable the follow up
> patch to add tests for nvme-ns generic character device.
> 
> Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>
> ---
>  test/nvme.h | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 168 insertions(+)
>  create mode 100644 test/nvme.h
> 
> diff --git a/test/nvme.h b/test/nvme.h
> new file mode 100644
> index 0000000..866a7e6
> --- /dev/null
> +++ b/test/nvme.h
> @@ -0,0 +1,168 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Description: Helpers for NVMe uring passthrough commands
> + */
> +#ifndef LIBURING_NVME_H
> +#define LIBURING_NVME_H
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#include <sys/ioctl.h>
> +#include <linux/nvme_ioctl.h>
> +
> +/*
> + * If the uapi headers installed on the system lacks nvme uring command
> + * support, use the local version to prevent compilation issues.
> + */
> +#ifndef CONFIG_HAVE_NVME_URING
> +struct nvme_uring_cmd {
> +	__u8	opcode;
> +	__u8	flags;
> +	__u16	rsvd1;
> +	__u32	nsid;
> +	__u32	cdw2;
> +	__u32	cdw3;
> +	__u64	metadata;
> +	__u64	addr;
> +	__u32	metadata_len;
> +	__u32	data_len;
> +	__u32	cdw10;
> +	__u32	cdw11;
> +	__u32	cdw12;
> +	__u32	cdw13;
> +	__u32	cdw14;
> +	__u32	cdw15;
> +	__u32	timeout_ms;
> +	__u32   rsvd2;
> +};
> +
> +#define NVME_URING_CMD_IO	_IOWR('N', 0x80, struct nvme_uring_cmd)
> +#define NVME_URING_CMD_IO_VEC	_IOWR('N', 0x81, struct nvme_uring_cmd)
> +#endif /* CONFIG_HAVE_NVME_URING */
> +
> +#define NVME_DEFAULT_IOCTL_TIMEOUT 0
> +#define NVME_IDENTIFY_DATA_SIZE 4096
> +#define NVME_IDENTIFY_CSI_SHIFT 24
> +#define NVME_IDENTIFY_CNS_NS 0
> +#define NVME_CSI_NVM 0
> +
> +enum nvme_admin_opcode {
> +	nvme_admin_identify		= 0x06,
> +};
> +
> +enum nvme_io_opcode {
> +	nvme_cmd_write			= 0x01,
> +	nvme_cmd_read			= 0x02,
> +};
> +
> +int nsid;
> +__u32 lba_shift;
> +
> +struct nvme_lbaf {
> +	__le16			ms;
> +	__u8			ds;
> +	__u8			rp;
> +};
> +
> +struct nvme_id_ns {
> +	__le64			nsze;
> +	__le64			ncap;
> +	__le64			nuse;
> +	__u8			nsfeat;
> +	__u8			nlbaf;
> +	__u8			flbas;
> +	__u8			mc;
> +	__u8			dpc;
> +	__u8			dps;
> +	__u8			nmic;
> +	__u8			rescap;
> +	__u8			fpi;
> +	__u8			dlfeat;
> +	__le16			nawun;
> +	__le16			nawupf;
> +	__le16			nacwu;
> +	__le16			nabsn;
> +	__le16			nabo;
> +	__le16			nabspf;
> +	__le16			noiob;
> +	__u8			nvmcap[16];
> +	__le16			npwg;
> +	__le16			npwa;
> +	__le16			npdg;
> +	__le16			npda;
> +	__le16			nows;
> +	__le16			mssrl;
> +	__le32			mcl;
> +	__u8			msrc;
> +	__u8			rsvd81[11];
> +	__le32			anagrpid;
> +	__u8			rsvd96[3];
> +	__u8			nsattr;
> +	__le16			nvmsetid;
> +	__le16			endgid;
> +	__u8			nguid[16];
> +	__u8			eui64[8];
> +	struct nvme_lbaf	lbaf[16];
> +	__u8			rsvd192[192];
> +	__u8			vs[3712];
> +};
> +
> +static inline int ilog2(uint32_t i)
> +{
> +	int log = -1;
> +
> +	while (i) {
> +		i >>= 1;
> +		log++;
> +	}
> +	return log;
> +}
> +
> +int fio_nvme_get_info(const char *file)
> +{
> +	struct nvme_id_ns ns;
> +	int fd, err;
> +	__u32 lba_size;
> +
> +	fd = open(file, O_RDONLY);
> +	if (fd < 0)
> +		return -errno;
> +
> +	nsid = ioctl(fd, NVME_IOCTL_ID);
> +	if (nsid < 0) {
> +		fprintf(stderr, "failed to fetch namespace-id\n");
> +		close(fd);
> +		return -errno;
> +	}
> +
> +	struct nvme_passthru_cmd cmd = {
> +		.opcode         = nvme_admin_identify,
> +		.nsid           = nsid,
> +		.addr           = (__u64)(uintptr_t)&ns,
> +		.data_len       = NVME_IDENTIFY_DATA_SIZE,
> +		.cdw10          = NVME_IDENTIFY_CNS_NS,
> +		.cdw11          = NVME_CSI_NVM << NVME_IDENTIFY_CSI_SHIFT,
> +		.timeout_ms     = NVME_DEFAULT_IOCTL_TIMEOUT,
> +	};
> +
> +	err = ioctl(fd, NVME_IOCTL_ADMIN_CMD, &cmd);
> +	if (err) {
> +		fprintf(stderr, "failed to fetch identify namespace\n");
> +		close(fd);
> +		return err;
> +	}
> +
> +	lba_size = 1 << ns.lbaf[(ns.flbas & 0x0f)].ds;
> +	lba_shift = ilog2(lba_size);
> +
> +	close(fd);
> +	return 0;
> +}

Too much copy pasting I think? Probably should not prefix this one with
fio?

-- 
Jens Axboe