[PATCH v3 RFC 2/2] nvme: improve performance for virtual NVMe devices

[J Freyensee]

On Mon, 2016-08-15 at 22:41 -0300, Helen Koike wrote:


>  
> +struct nvme_doorbell_memory {
> +	__u8			opcode;
> +	__u8			flags;
> +	__u16			command_id;
> +	__u32			rsvd1[5];
> +	__le64			prp1;
> +	__le64			prp2;
> +	__u32			rsvd12[6];
> +};
> +
>  struct nvme_command {
>  	union {
>  		struct nvme_common_command common;
> @@ -845,6 +858,7 @@ struct nvme_command {
>  		struct nvmf_connect_command connect;
>  		struct nvmf_property_set_command prop_set;
>  		struct nvmf_property_get_command prop_get;
> +		struct nvme_doorbell_memory doorbell_memory;
>  	};
>  };

This looks like a new NVMe command being introduced, not found in the
latest NVMe specs (NVMe 1.2.1 spec or NVMe-over-Fabrics 1.0 spec)?

This is a big NACK, the command needs to be part of the NVMe standard
before adding it to the NVMe code base (this is exactly how NVMe-over-
Fabrics standard got implemented).  I would bring your proposal to
nvmexpress.org.

Jay


>  
> @@ -934,6 +948,9 @@ enum {
>  	/*
>  	 * Media and Data Integrity Errors:
>  	 */
> +#ifdef CONFIG_NVME_VDB
> +	NVME_SC_DOORBELL_MEMORY_INVALID	= 0x1C0,
> +#endif
>  	NVME_SC_WRITE_FAULT		= 0x280,
>  	NVME_SC_READ_ERROR		= 0x281,
>  	NVME_SC_GUARD_CHECK		= 0x282,