kernel_optimize_test/drivers/vhost/tcm_vhost.h
Asias He 1b7f390eb3 tcm_vhost: Multi-queue support
This adds virtio-scsi multi-queue support to tcm_vhost. In order to use
multi-queue, guest side multi-queue support is need. It can
be found here:

   https://lkml.org/lkml/2012/12/18/166

Currently, only one thread is created by vhost core code for each
vhost_scsi instance. Even if there are multi-queues, all the handling of
guest kick (vhost_scsi_handle_kick) are processed in one thread. This is
not optimal. Luckily, most of the work is offloaded to the tcm_vhost
workqueue.

Some initial perf numbers:
1 queue,  4 targets, 1 lun per target
4K request size, 50% randread + 50% randwrite: 127K/127k IOPS

4 queues, 4 targets, 1 lun per target
4K request size, 50% randread + 50% randwrite: 181K/181k IOPS

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-02-13 11:30:14 -08:00

116 lines
3.9 KiB
C

#define TCM_VHOST_VERSION "v0.1"
#define TCM_VHOST_NAMELEN 256
#define TCM_VHOST_MAX_CDB_SIZE 32
struct tcm_vhost_cmd {
/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
int tvc_vq_desc;
/* virtio-scsi initiator task attribute */
int tvc_task_attr;
/* virtio-scsi initiator data direction */
enum dma_data_direction tvc_data_direction;
/* Expected data transfer length from virtio-scsi header */
u32 tvc_exp_data_len;
/* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
u64 tvc_tag;
/* The number of scatterlists associated with this cmd */
u32 tvc_sgl_count;
/* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
u32 tvc_lun;
/* Pointer to the SGL formatted memory from virtio-scsi */
struct scatterlist *tvc_sgl;
/* Pointer to response */
struct virtio_scsi_cmd_resp __user *tvc_resp;
/* Pointer to vhost_scsi for our device */
struct vhost_scsi *tvc_vhost;
/* Pointer to vhost_virtqueue for the cmd */
struct vhost_virtqueue *tvc_vq;
/* Pointer to vhost nexus memory */
struct tcm_vhost_nexus *tvc_nexus;
/* The TCM I/O descriptor that is accessed via container_of() */
struct se_cmd tvc_se_cmd;
/* work item used for cmwq dispatch to tcm_vhost_submission_work() */
struct work_struct work;
/* Copy of the incoming SCSI command descriptor block (CDB) */
unsigned char tvc_cdb[TCM_VHOST_MAX_CDB_SIZE];
/* Sense buffer that will be mapped into outgoing status */
unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
/* Completed commands list, serviced from vhost worker thread */
struct llist_node tvc_completion_list;
};
struct tcm_vhost_nexus {
/* Pointer to TCM session for I_T Nexus */
struct se_session *tvn_se_sess;
};
struct tcm_vhost_nacl {
/* Binary World Wide unique Port Name for Vhost Initiator port */
u64 iport_wwpn;
/* ASCII formatted WWPN for Sas Initiator port */
char iport_name[TCM_VHOST_NAMELEN];
/* Returned by tcm_vhost_make_nodeacl() */
struct se_node_acl se_node_acl;
};
struct tcm_vhost_tpg {
/* Vhost port target portal group tag for TCM */
u16 tport_tpgt;
/* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
int tv_tpg_port_count;
/* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
int tv_tpg_vhost_count;
/* list for tcm_vhost_list */
struct list_head tv_tpg_list;
/* Used to protect access for tpg_nexus */
struct mutex tv_tpg_mutex;
/* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
struct tcm_vhost_nexus *tpg_nexus;
/* Pointer back to tcm_vhost_tport */
struct tcm_vhost_tport *tport;
/* Returned by tcm_vhost_make_tpg() */
struct se_portal_group se_tpg;
};
struct tcm_vhost_tport {
/* SCSI protocol the tport is providing */
u8 tport_proto_id;
/* Binary World Wide unique Port Name for Vhost Target port */
u64 tport_wwpn;
/* ASCII formatted WWPN for Vhost Target port */
char tport_name[TCM_VHOST_NAMELEN];
/* Returned by tcm_vhost_make_tport() */
struct se_wwn tport_wwn;
};
/*
* As per request from MST, keep TCM_VHOST related ioctl defines out of
* linux/vhost.h (user-space) for now..
*/
#include <linux/vhost.h>
/*
* Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
*
* ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
* RFC-v2 vhost-scsi userspace. Add GET_ABI_VERSION ioctl usage
* ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
* All the targets under vhost_wwpn can be seen and used by guset.
*/
#define VHOST_SCSI_ABI_VERSION 1
struct vhost_scsi_target {
int abi_version;
char vhost_wwpn[TRANSPORT_IQN_LEN];
unsigned short vhost_tpgt;
unsigned short reserved;
};
/* VHOST_SCSI specific defines */
#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
/* Changing this breaks userspace. */
#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)