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Re: [Qemu-devel] [RFC-v5] tcm_vhost: Initial merge for vhost level targe
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From: |
Michael S. Tsirkin |
|
Subject: |
Re: [Qemu-devel] [RFC-v5] tcm_vhost: Initial merge for vhost level target fabric driver |
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Date: |
Sun, 29 Jul 2012 16:40:52 +0300 |
On Thu, Jul 26, 2012 at 11:43:20PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <address@hidden>
>
> Hello KVM + QEMU folks,
>
> This is -v5 of the in-flight tcm_vhost fabric driver for KVM host virtualized
> target support using the in-kernel storage stack with for-3.6 code.
>
> The changes since -v4 have been pretty minimal. A new GET_ABI_VERSION ioctl
> has been added as requested by Anthony & Co, and after some back <-> forth on
> the lists we've decided upon a starting point of VHOST_SCSI_ABI_VERSION=0,
> and vhost-scsi RFC userspace has been updated accordingly.
>
> Along with that, a few handfuls of vq related error messages where converted
> to use vq_err as requested by MST, along with some minor checkpatch fixes.
>
> So this point everything required to run tcm_vhost from drivers/target +
> drivers/vhost, and virtio-scsi LLD bugfix has been merged into v3.6-rc0 code.
>
> Please have a look and let us know if there are any last-minute pre-merge
> comments ahead of MST returning from holiday this weekend.
>
> Thank you!
>
> --nab
Acked-by: Michael S. Tsirkin <address@hidden>
some comments below but can be fixed in-tree I think.
> Changelog v4 -> v5:
>
> Expose ABI version via VHOST_SCSI_GET_ABI_VERSION + use Rev 0 as
> starting point for v3.6-rc code (Stefan + ALiguori + nab)
> Convert vhost_scsi_handle_vq() to vq_err() (nab + MST)
> Minor style fixes from checkpatch (nab)
>
> Changelog v3 -> v4:
>
> Rename vhost_vring_target -> vhost_scsi_target (mst + nab)
> Use TRANSPORT_IQN_LEN in vhost_scsi_target->vhost_wwpn[] def (nab)
> Move back to drivers/vhost/, and just use drivers/vhost/Kconfig.tcm (mst)
> Move TCM_VHOST related ioctl defines from include/linux/vhost.h ->
> drivers/vhost/tcm_vhost.h as requested by MST (nab)
> Move Kbuild.tcm include from drivers/staging -> drivers/vhost/, and
> just use 'if STAGING' around 'source drivers/vhost/Kbuild.tcm'
>
> Changelog v2 -> v3:
>
> Unlock on error in tcm_vhost_drop_nexus() (DanC)
> Fix strlen() doesn't count the terminator (DanC)
> Call kfree() on an error path (DanC)
> Convert tcm_vhost_write_pending to use target_execute_cmd (hch + nab)
> Fix another strlen() off by one in tcm_vhost_make_tport (DanC)
> Add option under drivers/staging/Kconfig, and move to drivers/vhost/tcm/
> as requested by MST (nab)
>
> Changelog v1 -> v2:
>
> Fix tv_cmd completion -> release SGL memory leak (nab)
> Fix sparse warnings for static variable usage ((Fengguang Wu)
> Fix sparse warnings for min() typing + printk format specs (Fengguang Wu)
> Convert to cmwq submission for I/O dispatch (nab + hch)
>
> Changelog v0 -> v1:
>
> Merge into single source + header file, and move to drivers/vhost/
>
> Cc: Michael S. Tsirkin <address@hidden>
> Cc: Stefan Hajnoczi <address@hidden>
> Cc: Anthony Liguori <address@hidden>
> Cc: Zhi Yong Wu <address@hidden>
> Cc: Paolo Bonzini <address@hidden>
> Cc: Christoph Hellwig <address@hidden>
> Cc: Hannes Reinecke <address@hidden>
> Cc: Jens Axboe <address@hidden>
> Signed-off-by: Nicholas Bellinger <address@hidden>
> ---
> drivers/vhost/Kconfig | 3 +
> drivers/vhost/Kconfig.tcm | 6 +
> drivers/vhost/Makefile | 2 +
> drivers/vhost/tcm_vhost.c | 1628
> +++++++++++++++++++++++++++++++++++++++++++++
> drivers/vhost/tcm_vhost.h | 101 +++
> 5 files changed, 1740 insertions(+), 0 deletions(-)
> create mode 100644 drivers/vhost/Kconfig.tcm
> create mode 100644 drivers/vhost/tcm_vhost.c
> create mode 100644 drivers/vhost/tcm_vhost.h
>
> diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
> index e4e2fd1..202bba6 100644
> --- a/drivers/vhost/Kconfig
> +++ b/drivers/vhost/Kconfig
> @@ -9,3 +9,6 @@ config VHOST_NET
> To compile this driver as a module, choose M here: the module will
> be called vhost_net.
>
> +if STAGING
> +source "drivers/vhost/Kconfig.tcm"
> +endif
> diff --git a/drivers/vhost/Kconfig.tcm b/drivers/vhost/Kconfig.tcm
> new file mode 100644
> index 0000000..a9c6f76
> --- /dev/null
> +++ b/drivers/vhost/Kconfig.tcm
> @@ -0,0 +1,6 @@
> +config TCM_VHOST
> + tristate "TCM_VHOST fabric module (EXPERIMENTAL)"
> + depends on TARGET_CORE && EVENTFD && EXPERIMENTAL && m
> + default n
> + ---help---
> + Say M here to enable the TCM_VHOST fabric module for use with
> virtio-scsi guests
> diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
> index 72dd020..a27b053 100644
> --- a/drivers/vhost/Makefile
> +++ b/drivers/vhost/Makefile
> @@ -1,2 +1,4 @@
> obj-$(CONFIG_VHOST_NET) += vhost_net.o
> vhost_net-y := vhost.o net.o
> +
> +obj-$(CONFIG_TCM_VHOST) += tcm_vhost.o
> diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> new file mode 100644
> index 0000000..fb36654
> --- /dev/null
> +++ b/drivers/vhost/tcm_vhost.c
> @@ -0,0 +1,1628 @@
> +/*******************************************************************************
> + * Vhost kernel TCM fabric driver for virtio SCSI initiators
> + *
> + * (C) Copyright 2010-2012 RisingTide Systems LLC.
> + * (C) Copyright 2010-2012 IBM Corp.
> + *
> + * Licensed to the Linux Foundation under the General Public License (GPL)
> version 2.
> + *
> + * Authors: Nicholas A. Bellinger <address@hidden>
> + * Stefan Hajnoczi <address@hidden>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> +
> ****************************************************************************/
> +
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <generated/utsrelease.h>
> +#include <linux/utsname.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/kthread.h>
> +#include <linux/types.h>
> +#include <linux/string.h>
> +#include <linux/configfs.h>
> +#include <linux/ctype.h>
> +#include <linux/compat.h>
> +#include <linux/eventfd.h>
> +#include <linux/vhost.h>
> +#include <linux/fs.h>
> +#include <linux/miscdevice.h>
> +#include <asm/unaligned.h>
> +#include <scsi/scsi.h>
> +#include <scsi/scsi_tcq.h>
> +#include <target/target_core_base.h>
> +#include <target/target_core_fabric.h>
> +#include <target/target_core_fabric_configfs.h>
> +#include <target/target_core_configfs.h>
> +#include <target/configfs_macros.h>
> +#include <linux/vhost.h>
> +#include <linux/virtio_net.h> /* TODO vhost.h currently depends on this */
> +#include <linux/virtio_scsi.h>
> +
> +#include "vhost.c"
> +#include "vhost.h"
> +#include "tcm_vhost.h"
> +
> +struct vhost_scsi {
> + atomic_t vhost_ref_cnt;
> + struct tcm_vhost_tpg *vs_tpg;
Would b enice to add a note on locking about this field.
> + struct vhost_dev dev;
> + struct vhost_virtqueue vqs[3];
> +
> + struct vhost_work vs_completion_work; /* cmd completion work item */
> + struct list_head vs_completion_list; /* cmd completion queue */
> + spinlock_t vs_completion_lock; /* protects s_completion_list */
> +};
> +
> +/* Local pointer to allocated TCM configfs fabric module */
> +static struct target_fabric_configfs *tcm_vhost_fabric_configfs;
> +
> +static struct workqueue_struct *tcm_vhost_workqueue;
> +
> +/* Global spinlock to protect tcm_vhost TPG list for vhost IOCTL access */
> +static DEFINE_MUTEX(tcm_vhost_mutex);
> +static LIST_HEAD(tcm_vhost_list);
> +
> +static int tcm_vhost_check_true(struct se_portal_group *se_tpg)
> +{
> + return 1;
> +}
> +
> +static int tcm_vhost_check_false(struct se_portal_group *se_tpg)
> +{
> + return 0;
> +}
> +
> +static char *tcm_vhost_get_fabric_name(void)
> +{
> + return "vhost";
> +}
> +
> +static u8 tcm_vhost_get_fabric_proto_ident(struct se_portal_group *se_tpg)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport = tpg->tport;
> +
> + switch (tport->tport_proto_id) {
> + case SCSI_PROTOCOL_SAS:
> + return sas_get_fabric_proto_ident(se_tpg);
> + case SCSI_PROTOCOL_FCP:
> + return fc_get_fabric_proto_ident(se_tpg);
> + case SCSI_PROTOCOL_ISCSI:
> + return iscsi_get_fabric_proto_ident(se_tpg);
> + default:
> + pr_err("Unknown tport_proto_id: 0x%02x, using"
> + " SAS emulation\n", tport->tport_proto_id);
> + break;
> + }
> +
> + return sas_get_fabric_proto_ident(se_tpg);
> +}
> +
> +static char *tcm_vhost_get_fabric_wwn(struct se_portal_group *se_tpg)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport = tpg->tport;
> +
> + return &tport->tport_name[0];
> +}
> +
> +static u16 tcm_vhost_get_tag(struct se_portal_group *se_tpg)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + return tpg->tport_tpgt;
> +}
> +
> +static u32 tcm_vhost_get_default_depth(struct se_portal_group *se_tpg)
> +{
> + return 1;
> +}
> +
> +static u32 tcm_vhost_get_pr_transport_id(
> + struct se_portal_group *se_tpg,
> + struct se_node_acl *se_nacl,
> + struct t10_pr_registration *pr_reg,
> + int *format_code,
> + unsigned char *buf)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport = tpg->tport;
> +
> + switch (tport->tport_proto_id) {
> + case SCSI_PROTOCOL_SAS:
> + return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
> + format_code, buf);
> + case SCSI_PROTOCOL_FCP:
> + return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
> + format_code, buf);
> + case SCSI_PROTOCOL_ISCSI:
> + return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
> + format_code, buf);
> + default:
> + pr_err("Unknown tport_proto_id: 0x%02x, using"
> + " SAS emulation\n", tport->tport_proto_id);
> + break;
> + }
> +
> + return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
> + format_code, buf);
> +}
> +
> +static u32 tcm_vhost_get_pr_transport_id_len(
> + struct se_portal_group *se_tpg,
> + struct se_node_acl *se_nacl,
> + struct t10_pr_registration *pr_reg,
> + int *format_code)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport = tpg->tport;
> +
> + switch (tport->tport_proto_id) {
> + case SCSI_PROTOCOL_SAS:
> + return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
> + format_code);
> + case SCSI_PROTOCOL_FCP:
> + return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
> + format_code);
> + case SCSI_PROTOCOL_ISCSI:
> + return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
> + format_code);
> + default:
> + pr_err("Unknown tport_proto_id: 0x%02x, using"
> + " SAS emulation\n", tport->tport_proto_id);
> + break;
> + }
> +
> + return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
> + format_code);
> +}
> +
> +static char *tcm_vhost_parse_pr_out_transport_id(
> + struct se_portal_group *se_tpg,
> + const char *buf,
> + u32 *out_tid_len,
> + char **port_nexus_ptr)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport = tpg->tport;
> +
> + switch (tport->tport_proto_id) {
> + case SCSI_PROTOCOL_SAS:
> + return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
> + port_nexus_ptr);
> + case SCSI_PROTOCOL_FCP:
> + return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
> + port_nexus_ptr);
> + case SCSI_PROTOCOL_ISCSI:
> + return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
> + port_nexus_ptr);
> + default:
> + pr_err("Unknown tport_proto_id: 0x%02x, using"
> + " SAS emulation\n", tport->tport_proto_id);
> + break;
> + }
> +
> + return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
> + port_nexus_ptr);
> +}
> +
> +static struct se_node_acl *tcm_vhost_alloc_fabric_acl(
> + struct se_portal_group *se_tpg)
> +{
> + struct tcm_vhost_nacl *nacl;
> +
> + nacl = kzalloc(sizeof(struct tcm_vhost_nacl), GFP_KERNEL);
> + if (!nacl) {
> + pr_err("Unable to alocate struct tcm_vhost_nacl\n");
> + return NULL;
> + }
> +
> + return &nacl->se_node_acl;
> +}
> +
> +static void tcm_vhost_release_fabric_acl(
> + struct se_portal_group *se_tpg,
> + struct se_node_acl *se_nacl)
> +{
> + struct tcm_vhost_nacl *nacl = container_of(se_nacl,
> + struct tcm_vhost_nacl, se_node_acl);
> + kfree(nacl);
> +}
> +
> +static u32 tcm_vhost_tpg_get_inst_index(struct se_portal_group *se_tpg)
> +{
> + return 1;
> +}
> +
> +static void tcm_vhost_release_cmd(struct se_cmd *se_cmd)
> +{
> + return;
> +}
> +
> +static int tcm_vhost_shutdown_session(struct se_session *se_sess)
> +{
> + return 0;
> +}
> +
> +static void tcm_vhost_close_session(struct se_session *se_sess)
> +{
> + return;
> +}
> +
> +static u32 tcm_vhost_sess_get_index(struct se_session *se_sess)
> +{
> + return 0;
> +}
> +
> +static int tcm_vhost_write_pending(struct se_cmd *se_cmd)
> +{
> + /* Go ahead and process the write immediately */
> + target_execute_cmd(se_cmd);
> + return 0;
> +}
> +
> +static int tcm_vhost_write_pending_status(struct se_cmd *se_cmd)
> +{
> + return 0;
> +}
> +
> +static void tcm_vhost_set_default_node_attrs(struct se_node_acl *nacl)
> +{
> + return;
> +}
> +
> +static u32 tcm_vhost_get_task_tag(struct se_cmd *se_cmd)
> +{
> + return 0;
> +}
> +
> +static int tcm_vhost_get_cmd_state(struct se_cmd *se_cmd)
> +{
> + return 0;
> +}
> +
> +static void vhost_scsi_complete_cmd(struct tcm_vhost_cmd *);
can we reorder code to avoid forward declarations?
> +
> +static int tcm_vhost_queue_data_in(struct se_cmd *se_cmd)
> +{
> + struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
> + struct tcm_vhost_cmd, tvc_se_cmd);
> + vhost_scsi_complete_cmd(tv_cmd);
> + return 0;
> +}
> +
> +static int tcm_vhost_queue_status(struct se_cmd *se_cmd)
> +{
> + struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
> + struct tcm_vhost_cmd, tvc_se_cmd);
> + vhost_scsi_complete_cmd(tv_cmd);
> + return 0;
> +}
> +
> +static int tcm_vhost_queue_tm_rsp(struct se_cmd *se_cmd)
> +{
> + return 0;
> +}
> +
> +static u16 tcm_vhost_set_fabric_sense_len(struct se_cmd *se_cmd,
> + u32 sense_length)
> +{
> + return 0;
> +}
> +
> +static u16 tcm_vhost_get_fabric_sense_len(void)
> +{
> + return 0;
> +}
> +
> +static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
> +{
> + struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
> +
> + /* TODO locking against target/backend threads? */
> + transport_generic_free_cmd(se_cmd, 1);
> +
> + if (tv_cmd->tvc_sgl_count) {
> + u32 i;
> + for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
> + put_page(sg_page(&tv_cmd->tvc_sgl[i]));
> +
> + kfree(tv_cmd->tvc_sgl);
> + }
> +
> + kfree(tv_cmd);
> +}
> +
> +/* Dequeue a command from the completion list */
> +static struct tcm_vhost_cmd *vhost_scsi_get_cmd_from_completion(
> + struct vhost_scsi *vs)
> +{
> + struct tcm_vhost_cmd *tv_cmd = NULL;
> +
> + spin_lock_bh(&vs->vs_completion_lock);
> + if (list_empty(&vs->vs_completion_list)) {
> + spin_unlock_bh(&vs->vs_completion_lock);
> + return NULL;
> + }
> +
> + list_for_each_entry(tv_cmd, &vs->vs_completion_list,
> + tvc_completion_list) {
> + list_del(&tv_cmd->tvc_completion_list);
> + break;
> + }
> + spin_unlock_bh(&vs->vs_completion_lock);
> + return tv_cmd;
> +}
> +
> +/* Fill in status and signal that we are done processing this command
> + *
> + * This is scheduled in the vhost work queue so we are called with the owner
> + * process mm and can access the vring.
> + */
> +static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
> +{
> + struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
> + vs_completion_work);
> + struct tcm_vhost_cmd *tv_cmd;
> +
> + while ((tv_cmd = vhost_scsi_get_cmd_from_completion(vs)) != NULL) {
I normally prefer while ((tv_cmd = vhost_scsi_get_cmd_from_completion(vs)))
without != NULL
> + struct virtio_scsi_cmd_resp v_rsp;
> + struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
> + int ret;
> +
> + pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
> + tv_cmd, se_cmd->residual_count, se_cmd->scsi_status);
> +
> + memset(&v_rsp, 0, sizeof(v_rsp));
> + v_rsp.resid = se_cmd->residual_count;
> + /* TODO is status_qualifier field needed? */
> + v_rsp.status = se_cmd->scsi_status;
> + v_rsp.sense_len = se_cmd->scsi_sense_length;
> + memcpy(v_rsp.sense, tv_cmd->tvc_sense_buf,
> + v_rsp.sense_len);
> + ret = copy_to_user(tv_cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
> + if (likely(ret == 0))
> + vhost_add_used(&vs->vqs[2], tv_cmd->tvc_vq_desc, 0);
> + else
> + pr_err("Faulted on virtio_scsi_cmd_resp\n");
> +
> + vhost_scsi_free_cmd(tv_cmd);
> + }
> +
> + vhost_signal(&vs->dev, &vs->vqs[2]);
> +}
> +
> +static void vhost_scsi_complete_cmd(struct tcm_vhost_cmd *tv_cmd)
> +{
> + struct vhost_scsi *vs = tv_cmd->tvc_vhost;
> +
> + pr_debug("%s tv_cmd %p\n", __func__, tv_cmd);
Is this doing something you can not already do with
tracing? If all these pr_debug messages are useful,
I think it's best to add a kconfig entry for them
so that they are off for people even if they build
debug kernels.
> +
> + spin_lock_bh(&vs->vs_completion_lock);
> + list_add_tail(&tv_cmd->tvc_completion_list, &vs->vs_completion_list);
> + spin_unlock_bh(&vs->vs_completion_lock);
> +
> + vhost_work_queue(&vs->dev, &vs->vs_completion_work);
> +}
> +
> +static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd(
> + struct tcm_vhost_tpg *tv_tpg,
> + struct virtio_scsi_cmd_req *v_req,
> + u32 exp_data_len,
> + int data_direction)
> +{
> + struct tcm_vhost_cmd *tv_cmd;
> + struct tcm_vhost_nexus *tv_nexus;
> + struct se_portal_group *se_tpg = &tv_tpg->se_tpg;
> + struct se_session *se_sess;
> + struct se_cmd *se_cmd;
> + int sam_task_attr;
> +
> + tv_nexus = tv_tpg->tpg_nexus;
> + if (!tv_nexus) {
> + pr_err("Unable to locate active struct tcm_vhost_nexus\n");
> + return ERR_PTR(-EIO);
> + }
> + se_sess = tv_nexus->tvn_se_sess;
> +
> + tv_cmd = kzalloc(sizeof(struct tcm_vhost_cmd), GFP_ATOMIC);
> + if (!tv_cmd) {
> + pr_err("Unable to allocate struct tcm_vhost_cmd\n");
> + return ERR_PTR(-ENOMEM);
> + }
> + INIT_LIST_HEAD(&tv_cmd->tvc_completion_list);
> + tv_cmd->tvc_tag = v_req->tag;
> +
> + se_cmd = &tv_cmd->tvc_se_cmd;
> + /*
> + * Locate the SAM Task Attr from virtio_scsi_cmd_req
> + */
> + sam_task_attr = v_req->task_attr;
> + /*
> + * Initialize struct se_cmd descriptor from TCM infrastructure
> + */
> + transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, exp_data_len,
> + data_direction, sam_task_attr,
> + &tv_cmd->tvc_sense_buf[0]);
> +
> +#if 0 /* FIXME: vhost_scsi_allocate_cmd() BIDI operation */
> + if (bidi)
> + se_cmd->se_cmd_flags |= SCF_BIDI;
> +#endif
> + return tv_cmd;
> +}
> +
> +/*
> + * Map a user memory range into a scatterlist
> + *
> + * Returns the number of scatterlist entries used or -errno on error.
> + */
> +static int vhost_scsi_map_to_sgl(struct scatterlist *sgl,
> + unsigned int sgl_count, void __user *ptr, size_t len, int write)
> +{
> + struct scatterlist *sg = sgl;
> + unsigned int npages = 0;
> + int ret;
> +
> + while (len > 0) {
> + struct page *page;
> + unsigned int offset = (uintptr_t)ptr & ~PAGE_MASK;
> + unsigned int nbytes = min_t(unsigned int,
> + PAGE_SIZE - offset, len);
> +
> + if (npages == sgl_count) {
> + ret = -ENOBUFS;
> + goto err;
> + }
> +
> + ret = get_user_pages_fast((unsigned long)ptr, 1, write, &page);
> + BUG_ON(ret == 0); /* we should either get our page or fail */
> + if (ret < 0)
> + goto err;
> +
> + sg_set_page(sg, page, nbytes, offset);
> + ptr += nbytes;
> + len -= nbytes;
> + sg++;
> + npages++;
> + }
> + return npages;
> +
> +err:
> + /* Put pages that we hold */
> + for (sg = sgl; sg != &sgl[npages]; sg++)
> + put_page(sg_page(sg));
> + return ret;
> +}
> +
> +static int vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *tv_cmd,
> + struct iovec *iov, unsigned int niov, int write)
> +{
> + int ret;
> + unsigned int i;
> + u32 sgl_count;
> + struct scatterlist *sg;
> +
> + /*
> + * Find out how long sglist needs to be
> + */
> + sgl_count = 0;
> + for (i = 0; i < niov; i++) {
> + sgl_count += (((uintptr_t)iov[i].iov_base + iov[i].iov_len +
> + PAGE_SIZE - 1) >> PAGE_SHIFT) -
> + ((uintptr_t)iov[i].iov_base >> PAGE_SHIFT);
> + }
> + /* TODO overflow checking */
> +
> + sg = kmalloc(sizeof(tv_cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);
> + if (!sg)
> + return -ENOMEM;
> + pr_debug("%s sg %p sgl_count %u is_err %ld\n", __func__,
> + sg, sgl_count, IS_ERR(sg));
> + sg_init_table(sg, sgl_count);
> +
> + tv_cmd->tvc_sgl = sg;
> + tv_cmd->tvc_sgl_count = sgl_count;
> +
> + pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);
> + for (i = 0; i < niov; i++) {
> + ret = vhost_scsi_map_to_sgl(sg, sgl_count, iov[i].iov_base,
> + iov[i].iov_len, write);
> + if (ret < 0) {
> + for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
> + put_page(sg_page(&tv_cmd->tvc_sgl[i]));
> + kfree(tv_cmd->tvc_sgl);
> + tv_cmd->tvc_sgl = NULL;
> + tv_cmd->tvc_sgl_count = 0;
> + return ret;
> + }
> +
> + sg += ret;
> + sgl_count -= ret;
> + }
> + return 0;
> +}
> +
> +static void tcm_vhost_submission_work(struct work_struct *work)
> +{
> + struct tcm_vhost_cmd *tv_cmd =
> + container_of(work, struct tcm_vhost_cmd, work);
> + struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
> + struct scatterlist *sg_ptr, *sg_bidi_ptr = NULL;
> + int rc, sg_no_bidi = 0;
> + /*
> + * Locate the struct se_lun pointer based on v_req->lun, and
> + * attach it to struct se_cmd
> + */
> + rc = transport_lookup_cmd_lun(&tv_cmd->tvc_se_cmd, tv_cmd->tvc_lun);
> + if (rc < 0) {
> + pr_err("Failed to look up lun: %d\n", tv_cmd->tvc_lun);
> + transport_send_check_condition_and_sense(&tv_cmd->tvc_se_cmd,
> + tv_cmd->tvc_se_cmd.scsi_sense_reason, 0);
> + transport_generic_free_cmd(se_cmd, 0);
> + return;
> + }
> +
> + rc = target_setup_cmd_from_cdb(se_cmd, tv_cmd->tvc_cdb);
> + if (rc == -ENOMEM) {
> + transport_send_check_condition_and_sense(se_cmd,
> + TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
> + transport_generic_free_cmd(se_cmd, 0);
> + return;
> + } else if (rc < 0) {
> + if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
> + tcm_vhost_queue_status(se_cmd);
> + else
> + transport_send_check_condition_and_sense(se_cmd,
> + se_cmd->scsi_sense_reason, 0);
> + transport_generic_free_cmd(se_cmd, 0);
> + return;
> + }
> +
> + if (tv_cmd->tvc_sgl_count) {
> + sg_ptr = tv_cmd->tvc_sgl;
> + /*
> + * For BIDI commands, pass in the extra READ buffer
> + * to transport_generic_map_mem_to_cmd() below..
> + */
> +/* FIXME: Fix BIDI operation in tcm_vhost_submission_work() */
> +#if 0
> + if (se_cmd->se_cmd_flags & SCF_BIDI) {
> + sg_bidi_ptr = NULL;
> + sg_no_bidi = 0;
> + }
> +#endif
> + } else {
> + sg_ptr = NULL;
> + }
> +
> + rc = transport_generic_map_mem_to_cmd(se_cmd, sg_ptr,
> + tv_cmd->tvc_sgl_count, sg_bidi_ptr,
> + sg_no_bidi);
> + if (rc < 0) {
> + transport_send_check_condition_and_sense(se_cmd,
> + se_cmd->scsi_sense_reason, 0);
> + transport_generic_free_cmd(se_cmd, 0);
> + return;
> + }
> + transport_handle_cdb_direct(se_cmd);
> +}
> +
> +static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> +{
> + struct vhost_virtqueue *vq = &vs->vqs[2];
> + struct virtio_scsi_cmd_req v_req;
> + struct tcm_vhost_tpg *tv_tpg;
> + struct tcm_vhost_cmd *tv_cmd;
> + u32 exp_data_len, data_first, data_num, data_direction;
> + unsigned out, in, i;
> + int head, ret;
> +
> + /* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
> + tv_tpg = vs->vs_tpg;
> + if (unlikely(!tv_tpg)) {
> + pr_err("%s endpoint not set\n", __func__);
> + return;
> + }
> +
> + mutex_lock(&vq->mutex);
> + vhost_disable_notify(&vs->dev, vq);
> +
> + for (;;) {
> + head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
> + ARRAY_SIZE(vq->iov), &out, &in,
> + NULL, NULL);
> + pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
> + head, out, in);
> + /* On error, stop handling until the next kick. */
> + if (unlikely(head < 0))
> + break;
> + /* Nothing new? Wait for eventfd to tell us they refilled. */
> + if (head == vq->num) {
> + if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
> + vhost_disable_notify(&vs->dev, vq);
> + continue;
> + }
> + break;
> + }
> +
> +/* FIXME: BIDI operation */
> + if (out == 1 && in == 1) {
> + data_direction = DMA_NONE;
> + data_first = 0;
> + data_num = 0;
> + } else if (out == 1 && in > 1) {
> + data_direction = DMA_FROM_DEVICE;
> + data_first = out + 1;
> + data_num = in - 1;
> + } else if (out > 1 && in == 1) {
> + data_direction = DMA_TO_DEVICE;
> + data_first = 1;
> + data_num = out - 1;
> + } else {
> + vq_err(vq, "Invalid buffer layout out: %u in: %u\n",
> + out, in);
> + break;
> + }
> +
> + /*
> + * Check for a sane resp buffer so we can report errors to
> + * the guest.
> + */
> + if (unlikely(vq->iov[out].iov_len !=
> + sizeof(struct virtio_scsi_cmd_resp))) {
> + vq_err(vq, "Expecting virtio_scsi_cmd_resp, got %zu"
> + " bytes\n", vq->iov[out].iov_len);
> + break;
> + }
> +
> + if (unlikely(vq->iov[0].iov_len != sizeof(v_req))) {
> + vq_err(vq, "Expecting virtio_scsi_cmd_req, got %zu"
> + " bytes\n", vq->iov[0].iov_len);
> + break;
> + }
> + pr_debug("Calling __copy_from_user: vq->iov[0].iov_base: %p,"
> + " len: %zu\n", vq->iov[0].iov_base, sizeof(v_req));
> + ret = __copy_from_user(&v_req, vq->iov[0].iov_base,
> + sizeof(v_req));
> + if (unlikely(ret)) {
> + vq_err(vq, "Faulted on virtio_scsi_cmd_req\n");
> + break;
> + }
> +
> + exp_data_len = 0;
> + for (i = 0; i < data_num; i++)
> + exp_data_len += vq->iov[data_first + i].iov_len;
> +
> + tv_cmd = vhost_scsi_allocate_cmd(tv_tpg, &v_req,
> + exp_data_len, data_direction);
> + if (IS_ERR(tv_cmd)) {
> + vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n",
> + PTR_ERR(tv_cmd));
> + break;
> + }
> + pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
> + ": %d\n", tv_cmd, exp_data_len, data_direction);
> +
> + tv_cmd->tvc_vhost = vs;
> +
> + if (unlikely(vq->iov[out].iov_len !=
> + sizeof(struct virtio_scsi_cmd_resp))) {
> + vq_err(vq, "Expecting virtio_scsi_cmd_resp, got %zu"
> + " bytes, out: %d, in: %d\n",
> + vq->iov[out].iov_len, out, in);
> + break;
> + }
> +
> + tv_cmd->tvc_resp = vq->iov[out].iov_base;
> +
> + /*
> + * Copy in the recieved CDB descriptor into tv_cmd->tvc_cdb
> + * that will be used by tcm_vhost_new_cmd_map() and down into
> + * target_setup_cmd_from_cdb()
> + */
> + memcpy(tv_cmd->tvc_cdb, v_req.cdb, TCM_VHOST_MAX_CDB_SIZE);
> + /*
> + * Check that the recieved CDB size does not exceeded our
> + * hardcoded max for tcm_vhost
> + */
> + /* TODO what if cdb was too small for varlen cdb header? */
> + if (unlikely(scsi_command_size(tv_cmd->tvc_cdb) >
> + TCM_VHOST_MAX_CDB_SIZE)) {
> + vq_err(vq, "Received SCSI CDB with command_size: %d
> that"
> + " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
> + scsi_command_size(tv_cmd->tvc_cdb),
> + TCM_VHOST_MAX_CDB_SIZE);
> + break; /* TODO */
> + }
> + tv_cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
> +
> + pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
> + tv_cmd->tvc_cdb[0], tv_cmd->tvc_lun);
> +
> + if (data_direction != DMA_NONE) {
> + ret = vhost_scsi_map_iov_to_sgl(tv_cmd,
> + &vq->iov[data_first], data_num,
> + data_direction == DMA_TO_DEVICE);
> + if (unlikely(ret)) {
> + vq_err(vq, "Failed to map iov to sgl\n");
> + break; /* TODO */
> + }
> + }
> +
> + /*
> + * Save the descriptor from vhost_get_vq_desc() to be used to
> + * complete the virtio-scsi request in TCM callback context via
> + * tcm_vhost_queue_data_in() and tcm_vhost_queue_status()
> + */
> + tv_cmd->tvc_vq_desc = head;
> + /*
> + * Dispatch tv_cmd descriptor for cmwq execution in process
> + * context provided by tcm_vhost_workqueue. This also ensures
> + * tv_cmd is executed on the same kworker CPU as this vhost
> + * thread to gain positive L2 cache locality effects..
> + */
> + INIT_WORK(&tv_cmd->work, tcm_vhost_submission_work);
> + queue_work(tcm_vhost_workqueue, &tv_cmd->work);
> + }
> +
> + mutex_unlock(&vq->mutex);
> +}
> +
> +static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
> +{
> + pr_err("%s: The handling func for control queue.\n", __func__);
> +}
> +
> +static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
> +{
> + pr_err("%s: The handling func for event queue.\n", __func__);
> +}
> +
can userspace still trigger these? If not pls add a comment explaining
why are above never triggering.
> +static void vhost_scsi_handle_kick(struct vhost_work *work)
> +{
> + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> + poll.work);
> + struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
> +
> + vhost_scsi_handle_vq(vs);
> +}
> +
> +/*
> + * Called from vhost_scsi_ioctl() context to walk the list of available
> + * tcm_vhost_tpg with an active struct tcm_vhost_nexus
> + */
> +static int vhost_scsi_set_endpoint(
> + struct vhost_scsi *vs,
> + struct vhost_scsi_target *t)
> +{
> + struct tcm_vhost_tport *tv_tport;
> + struct tcm_vhost_tpg *tv_tpg;
> + int index;
> +
> + mutex_lock(&vs->dev.mutex);
> + /* Verify that ring has been setup correctly. */
> + for (index = 0; index < vs->dev.nvqs; ++index) {
> + /* Verify that ring has been setup correctly. */
> + if (!vhost_vq_access_ok(&vs->vqs[index])) {
> + mutex_unlock(&vs->dev.mutex);
> + return -EFAULT;
> + }
> + }
> +
> + if (vs->vs_tpg) {
> + mutex_unlock(&vs->dev.mutex);
> + return -EEXIST;
> + }
> + mutex_unlock(&vs->dev.mutex);
vs->vs_tpg can change at this point and be != NULL in loop below. Not an issue?
> + mutex_lock(&tcm_vhost_mutex);
> + list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
If you move this loop to a function, then it can use goto to cleanup on error.
> + mutex_lock(&tv_tpg->tv_tpg_mutex);
> + if (!tv_tpg->tpg_nexus) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + continue;
> + }
> + if (atomic_read(&tv_tpg->tv_tpg_vhost_count)) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + continue;
> + }
> + tv_tport = tv_tpg->tport;
> +
> + if (!strcmp(tv_tport->tport_name, t->vhost_wwpn) &&
> + (tv_tpg->tport_tpgt == t->vhost_tpgt)) {
> + atomic_inc(&tv_tpg->tv_tpg_vhost_count);
> + smp_mb__after_atomic_inc();
this an other uses of memory barriers need a comment: what are we
flushing out and why. Also - could something like kref be used for
reference counting? If this is not datapath this might be better.
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + mutex_unlock(&tcm_vhost_mutex);
> +
> + mutex_lock(&vs->dev.mutex);
> + vs->vs_tpg = tv_tpg;
> + atomic_inc(&vs->vhost_ref_cnt);
> + smp_mb__after_atomic_inc();
> + mutex_unlock(&vs->dev.mutex);
> + return 0;
> + }
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + }
> + mutex_unlock(&tcm_vhost_mutex);
> + return -EINVAL;
> +}
> +
> +static int vhost_scsi_clear_endpoint(
> + struct vhost_scsi *vs,
> + struct vhost_scsi_target *t)
> +{
> + struct tcm_vhost_tport *tv_tport;
> + struct tcm_vhost_tpg *tv_tpg;
> + int index;
> +
> + mutex_lock(&vs->dev.mutex);
> + /* Verify that ring has been setup correctly. */
> + for (index = 0; index < vs->dev.nvqs; ++index) {
> + if (!vhost_vq_access_ok(&vs->vqs[index])) {
> + mutex_unlock(&vs->dev.mutex);
> + return -EFAULT;
> + }
> + }
> +
> + if (!vs->vs_tpg) {
> + mutex_unlock(&vs->dev.mutex);
> + return -ENODEV;
> + }
> + tv_tpg = vs->vs_tpg;
> + tv_tport = tv_tpg->tport;
> +
> + if (strcmp(tv_tport->tport_name, t->vhost_wwpn) ||
> + (tv_tpg->tport_tpgt != t->vhost_tpgt)) {
> + mutex_unlock(&vs->dev.mutex);
> + pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"
> + " does not match t->vhost_wwpn: %s, t->vhost_tpgt:
> %hu\n",
> + tv_tport->tport_name, tv_tpg->tport_tpgt,
> + t->vhost_wwpn, t->vhost_tpgt);
> + return -EINVAL;
> + }
> + atomic_dec(&tv_tpg->tv_tpg_vhost_count);
> + vs->vs_tpg = NULL;
> + mutex_unlock(&vs->dev.mutex);
> +
> + return 0;
We could do it like this:
err:
mutex_unlock(&vs->dev.mutex);
return ret;
to make it clear we do not exit this with lock taken
> +}
> +
> +static int vhost_scsi_open(struct inode *inode, struct file *f)
> +{
> + struct vhost_scsi *s;
> + int r;
> +
> + s = kzalloc(sizeof(*s), GFP_KERNEL);
> + if (!s)
> + return -ENOMEM;
> +
> + vhost_work_init(&s->vs_completion_work, vhost_scsi_complete_cmd_work);
> + INIT_LIST_HEAD(&s->vs_completion_list);
> + spin_lock_init(&s->vs_completion_lock);
> +
> + s->vqs[0].handle_kick = vhost_scsi_ctl_handle_kick;
> + s->vqs[1].handle_kick = vhost_scsi_evt_handle_kick;
> + s->vqs[2].handle_kick = vhost_scsi_handle_kick;
better to add an enum with VQ numbers.
> + r = vhost_dev_init(&s->dev, s->vqs, 3);
> + if (r < 0) {
> + kfree(s);
> + return r;
> + }
> +
> + f->private_data = s;
> + return 0;
> +}
> +
> +static int vhost_scsi_release(struct inode *inode, struct file *f)
> +{
> + struct vhost_scsi *s = f->private_data;
> +
> + if (s->vs_tpg && s->vs_tpg->tport) {
> + struct vhost_scsi_target backend;
> +
> + memcpy(backend.vhost_wwpn, s->vs_tpg->tport->tport_name,
> + sizeof(backend.vhost_wwpn));
> + backend.vhost_tpgt = s->vs_tpg->tport_tpgt;
> + vhost_scsi_clear_endpoint(s, &backend);
> + }
> +
> + vhost_dev_cleanup(&s->dev, false);
> + kfree(s);
> + return 0;
> +}
> +
> +static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
> +{
> + if (features & ~VHOST_FEATURES)
> + return -EOPNOTSUPP;
> +
> + mutex_lock(&vs->dev.mutex);
> + if ((features & (1 << VHOST_F_LOG_ALL)) &&
> + !vhost_log_access_ok(&vs->dev)) {
> + mutex_unlock(&vs->dev.mutex);
> + return -EFAULT;
> + }
> + vs->dev.acked_features = features;
> + /* TODO possibly smp_wmb() and flush vqs */
Either that or fail if already running.
Current userspace does not change features once set,
but it's cleaner not to make assumptions.
> + mutex_unlock(&vs->dev.mutex);
> + return 0;
> +}
> +
> +static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
> + unsigned long arg)
> +{
> + struct vhost_scsi *vs = f->private_data;
> + struct vhost_scsi_target backend;
> + void __user *argp = (void __user *)arg;
> + u64 __user *featurep = argp;
> + u64 features;
> + int r;
> +
> + switch (ioctl) {
> + case VHOST_SCSI_SET_ENDPOINT:
> + if (copy_from_user(&backend, argp, sizeof backend))
> + return -EFAULT;
> +
> + return vhost_scsi_set_endpoint(vs, &backend);
> + case VHOST_SCSI_CLEAR_ENDPOINT:
> + if (copy_from_user(&backend, argp, sizeof backend))
> + return -EFAULT;
> +
> + return vhost_scsi_clear_endpoint(vs, &backend);
> + case VHOST_SCSI_GET_ABI_VERSION:
> + if (copy_from_user(&backend, argp, sizeof backend))
> + return -EFAULT;
Why are we reading this in BTW?
> +
> + backend.abi_version = VHOST_SCSI_ABI_VERSION;
> +
> + if (copy_to_user(argp, &backend, sizeof backend))
> + return -EFAULT;
> + return 0;
> + case VHOST_GET_FEATURES:
> + features = VHOST_FEATURES;
> + if (copy_to_user(featurep, &features, sizeof features))
> + return -EFAULT;
> + return 0;
> + case VHOST_SET_FEATURES:
> + if (copy_from_user(&features, featurep, sizeof features))
> + return -EFAULT;
> + return vhost_scsi_set_features(vs, features);
> + default:
> + mutex_lock(&vs->dev.mutex);
> + r = vhost_dev_ioctl(&vs->dev, ioctl, arg);
> + mutex_unlock(&vs->dev.mutex);
> + return r;
> + }
> +}
> +
> +static const struct file_operations vhost_scsi_fops = {
> + .owner = THIS_MODULE,
> + .release = vhost_scsi_release,
> + .unlocked_ioctl = vhost_scsi_ioctl,
> + /* TODO compat ioctl? */
well?
> + .open = vhost_scsi_open,
> + .llseek = noop_llseek,
> +};
> +
> +static struct miscdevice vhost_scsi_misc = {
> + MISC_DYNAMIC_MINOR,
> + "vhost-scsi",
> + &vhost_scsi_fops,
> +};
> +
> +static int __init vhost_scsi_register(void)
> +{
> + return misc_register(&vhost_scsi_misc);
> +}
> +
> +static int vhost_scsi_deregister(void)
> +{
> + return misc_deregister(&vhost_scsi_misc);
> +}
> +
> +static char *tcm_vhost_dump_proto_id(struct tcm_vhost_tport *tport)
> +{
> + switch (tport->tport_proto_id) {
> + case SCSI_PROTOCOL_SAS:
> + return "SAS";
> + case SCSI_PROTOCOL_FCP:
> + return "FCP";
> + case SCSI_PROTOCOL_ISCSI:
> + return "iSCSI";
> + default:
> + break;
> + }
> +
> + return "Unknown";
> +}
> +
> +static int tcm_vhost_port_link(
> + struct se_portal_group *se_tpg,
> + struct se_lun *lun)
I'd like this and other places to be like this:
static int tcm_vhost_port_link(struct se_portal_group *se_tpg,
struct se_lun *lun)
or
static int
tcm_vhost_port_link(struct se_portal_group *se_tpg,
struct se_lun *lun)
so that it's more like the rest of vhost code.
> +{
> + struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> +
> + atomic_inc(&tv_tpg->tv_tpg_port_count);
> + smp_mb__after_atomic_inc();
> +
> + return 0;
> +}
> +
> +static void tcm_vhost_port_unlink(
> + struct se_portal_group *se_tpg,
> + struct se_lun *se_lun)
> +{
> + struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> +
> + atomic_dec(&tv_tpg->tv_tpg_port_count);
> + smp_mb__after_atomic_dec();
> +}
> +
> +static struct se_node_acl *tcm_vhost_make_nodeacl(
> + struct se_portal_group *se_tpg,
> + struct config_group *group,
> + const char *name)
> +{
> + struct se_node_acl *se_nacl, *se_nacl_new;
> + struct tcm_vhost_nacl *nacl;
> + u64 wwpn = 0;
> + u32 nexus_depth;
> +
> + /* tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
> + return ERR_PTR(-EINVAL); */
> + se_nacl_new = tcm_vhost_alloc_fabric_acl(se_tpg);
> + if (!se_nacl_new)
> + return ERR_PTR(-ENOMEM);
> +
> + nexus_depth = 1;
> + /*
> + * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
> + * when converting a NodeACL from demo mode -> explict
> + */
> + se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
> + name, nexus_depth);
> + if (IS_ERR(se_nacl)) {
> + tcm_vhost_release_fabric_acl(se_tpg, se_nacl_new);
> + return se_nacl;
> + }
> + /*
> + * Locate our struct tcm_vhost_nacl and set the FC Nport WWPN
> + */
> + nacl = container_of(se_nacl, struct tcm_vhost_nacl, se_node_acl);
> + nacl->iport_wwpn = wwpn;
> +
> + return se_nacl;
> +}
> +
> +static void tcm_vhost_drop_nodeacl(struct se_node_acl *se_acl)
> +{
> + struct tcm_vhost_nacl *nacl = container_of(se_acl,
> + struct tcm_vhost_nacl, se_node_acl);
> + core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
> + kfree(nacl);
> +}
> +
> +static int tcm_vhost_make_nexus(
> + struct tcm_vhost_tpg *tv_tpg,
> + const char *name)
> +{
> + struct se_portal_group *se_tpg;
> + struct tcm_vhost_nexus *tv_nexus;
> +
> + mutex_lock(&tv_tpg->tv_tpg_mutex);
> + if (tv_tpg->tpg_nexus) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + pr_debug("tv_tpg->tpg_nexus already exists\n");
> + return -EEXIST;
> + }
> + se_tpg = &tv_tpg->se_tpg;
> +
> + tv_nexus = kzalloc(sizeof(struct tcm_vhost_nexus), GFP_KERNEL);
> + if (!tv_nexus) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + pr_err("Unable to allocate struct tcm_vhost_nexus\n");
> + return -ENOMEM;
> + }
> + /*
> + * Initialize the struct se_session pointer
> + */
> + tv_nexus->tvn_se_sess = transport_init_session();
> + if (IS_ERR(tv_nexus->tvn_se_sess)) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + kfree(tv_nexus);
> + return -ENOMEM;
> + }
> + /*
> + * Since we are running in 'demo mode' this call with generate a
> + * struct se_node_acl for the tcm_vhost struct se_portal_group with
> + * the SCSI Initiator port name of the passed configfs group 'name'.
> + */
> + tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
> + se_tpg, (unsigned char *)name);
> + if (!tv_nexus->tvn_se_sess->se_node_acl) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + pr_debug("core_tpg_check_initiator_node_acl() failed"
> + " for %s\n", name);
> + transport_free_session(tv_nexus->tvn_se_sess);
> + kfree(tv_nexus);
> + return -ENOMEM;
> + }
> + /*
> + * Now register the TCM vHost virtual I_T Nexus as active with the
I think s/vHost/vhost/ would be nice :)
> + * call to __transport_register_session()
> + */
> + __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
> + tv_nexus->tvn_se_sess, tv_nexus);
> + tv_tpg->tpg_nexus = tv_nexus;
> +
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + return 0;
> +}
> +
> +static int tcm_vhost_drop_nexus(
> + struct tcm_vhost_tpg *tpg)
> +{
> + struct se_session *se_sess;
> + struct tcm_vhost_nexus *tv_nexus;
> +
> + mutex_lock(&tpg->tv_tpg_mutex);
> + tv_nexus = tpg->tpg_nexus;
> + if (!tv_nexus) {
> + mutex_unlock(&tpg->tv_tpg_mutex);
> + return -ENODEV;
> + }
> +
> + se_sess = tv_nexus->tvn_se_sess;
> + if (!se_sess) {
> + mutex_unlock(&tpg->tv_tpg_mutex);
> + return -ENODEV;
> + }
> +
> + if (atomic_read(&tpg->tv_tpg_port_count)) {
> + mutex_unlock(&tpg->tv_tpg_mutex);
> + pr_err("Unable to remove TCM_vHost I_T Nexus with"
> + " active TPG port count: %d\n",
> + atomic_read(&tpg->tv_tpg_port_count));
> + return -EPERM;
EBUSY?
> + }
> +
> + if (atomic_read(&tpg->tv_tpg_vhost_count)) {
> + mutex_unlock(&tpg->tv_tpg_mutex);
> + pr_err("Unable to remove TCM_vHost I_T Nexus with"
> + " active TPG vhost count: %d\n",
> + atomic_read(&tpg->tv_tpg_vhost_count));
> + return -EPERM;
Same?
> + }
> +
> + pr_debug("TCM_vHost_ConfigFS: Removing I_T Nexus to emulated"
> + " %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),
> + tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
> + /*
> + * Release the SCSI I_T Nexus to the emulated vHost Target Port
> + */
> + transport_deregister_session(tv_nexus->tvn_se_sess);
> + tpg->tpg_nexus = NULL;
> + mutex_unlock(&tpg->tv_tpg_mutex);
> +
> + kfree(tv_nexus);
> + return 0;
> +}
> +
> +static ssize_t tcm_vhost_tpg_show_nexus(
> + struct se_portal_group *se_tpg,
> + char *page)
> +{
> + struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_nexus *tv_nexus;
> + ssize_t ret;
> +
> + mutex_lock(&tv_tpg->tv_tpg_mutex);
> + tv_nexus = tv_tpg->tpg_nexus;
> + if (!tv_nexus) {
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> + return -ENODEV;
> + }
> + ret = snprintf(page, PAGE_SIZE, "%s\n",
> + tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
> + mutex_unlock(&tv_tpg->tv_tpg_mutex);
> +
> + return ret;
> +}
> +
> +static ssize_t tcm_vhost_tpg_store_nexus(
> + struct se_portal_group *se_tpg,
> + const char *page,
> + size_t count)
> +{
> + struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> + struct tcm_vhost_tport *tport_wwn = tv_tpg->tport;
> + unsigned char i_port[TCM_VHOST_NAMELEN], *ptr, *port_ptr;
> + int ret;
> + /*
> + * Shutdown the active I_T nexus if 'NULL' is passed..
> + */
> + if (!strncmp(page, "NULL", 4)) {
> + ret = tcm_vhost_drop_nexus(tv_tpg);
> + return (!ret) ? count : ret;
> + }
> + /*
> + * Otherwise make sure the passed virtual Initiator port WWN matches
> + * the fabric protocol_id set in tcm_vhost_make_tport(), and call
> + * tcm_vhost_make_nexus().
> + */
> + if (strlen(page) >= TCM_VHOST_NAMELEN) {
> + pr_err("Emulated NAA Sas Address: %s, exceeds"
> + " max: %d\n", page, TCM_VHOST_NAMELEN);
> + return -EINVAL;
> + }
> + snprintf(&i_port[0], TCM_VHOST_NAMELEN, "%s", page);
> +
> + ptr = strstr(i_port, "naa.");
> + if (ptr) {
> + if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
> + pr_err("Passed SAS Initiator Port %s does not"
> + " match target port protoid: %s\n", i_port,
> + tcm_vhost_dump_proto_id(tport_wwn));
> + return -EINVAL;
> + }
> + port_ptr = &i_port[0];
> + goto check_newline;
> + }
> + ptr = strstr(i_port, "fc.");
> + if (ptr) {
> + if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
> + pr_err("Passed FCP Initiator Port %s does not"
> + " match target port protoid: %s\n", i_port,
> + tcm_vhost_dump_proto_id(tport_wwn));
> + return -EINVAL;
> + }
> + port_ptr = &i_port[3]; /* Skip over "fc." */
> + goto check_newline;
> + }
> + ptr = strstr(i_port, "iqn.");
> + if (ptr) {
> + if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
> + pr_err("Passed iSCSI Initiator Port %s does not"
> + " match target port protoid: %s\n", i_port,
> + tcm_vhost_dump_proto_id(tport_wwn));
> + return -EINVAL;
> + }
> + port_ptr = &i_port[0];
> + goto check_newline;
> + }
> + pr_err("Unable to locate prefix for emulated Initiator Port:"
> + " %s\n", i_port);
> + return -EINVAL;
> + /*
> + * Clear any trailing newline for the NAA WWN
> + */
> +check_newline:
> + if (i_port[strlen(i_port)-1] == '\n')
> + i_port[strlen(i_port)-1] = '\0';
> +
> + ret = tcm_vhost_make_nexus(tv_tpg, port_ptr);
> + if (ret < 0)
> + return ret;
> +
> + return count;
> +}
> +
> +TF_TPG_BASE_ATTR(tcm_vhost, nexus, S_IRUGO | S_IWUSR);
> +
> +static struct configfs_attribute *tcm_vhost_tpg_attrs[] = {
> + &tcm_vhost_tpg_nexus.attr,
> + NULL,
> +};
> +
> +static struct se_portal_group *tcm_vhost_make_tpg(
> + struct se_wwn *wwn,
> + struct config_group *group,
> + const char *name)
> +{
> + struct tcm_vhost_tport *tport = container_of(wwn,
> + struct tcm_vhost_tport, tport_wwn);
> +
> + struct tcm_vhost_tpg *tpg;
> + unsigned long tpgt;
> + int ret;
> +
> + if (strstr(name, "tpgt_") != name)
> + return ERR_PTR(-EINVAL);
> + if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
> + return ERR_PTR(-EINVAL);
> +
> + tpg = kzalloc(sizeof(struct tcm_vhost_tpg), GFP_KERNEL);
> + if (!tpg) {
> + pr_err("Unable to allocate struct tcm_vhost_tpg");
> + return ERR_PTR(-ENOMEM);
> + }
> + mutex_init(&tpg->tv_tpg_mutex);
> + INIT_LIST_HEAD(&tpg->tv_tpg_list);
> + tpg->tport = tport;
> + tpg->tport_tpgt = tpgt;
> +
> + ret = core_tpg_register(&tcm_vhost_fabric_configfs->tf_ops, wwn,
> + &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
> + if (ret < 0) {
> + kfree(tpg);
> + return NULL;
> + }
> + mutex_lock(&tcm_vhost_mutex);
> + list_add_tail(&tpg->tv_tpg_list, &tcm_vhost_list);
> + mutex_unlock(&tcm_vhost_mutex);
> +
> + return &tpg->se_tpg;
> +}
> +
> +static void tcm_vhost_drop_tpg(struct se_portal_group *se_tpg)
> +{
> + struct tcm_vhost_tpg *tpg = container_of(se_tpg,
> + struct tcm_vhost_tpg, se_tpg);
> +
> + mutex_lock(&tcm_vhost_mutex);
> + list_del(&tpg->tv_tpg_list);
> + mutex_unlock(&tcm_vhost_mutex);
> + /*
> + * Release the virtual I_T Nexus for this vHost TPG
> + */
> + tcm_vhost_drop_nexus(tpg);
> + /*
> + * Deregister the se_tpg from TCM..
> + */
> + core_tpg_deregister(se_tpg);
> + kfree(tpg);
> +}
> +
> +static struct se_wwn *tcm_vhost_make_tport(
> + struct target_fabric_configfs *tf,
> + struct config_group *group,
> + const char *name)
> +{
> + struct tcm_vhost_tport *tport;
> + char *ptr;
> + u64 wwpn = 0;
> + int off = 0;
> +
> + /* if (tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
> + return ERR_PTR(-EINVAL); */
> +
> + tport = kzalloc(sizeof(struct tcm_vhost_tport), GFP_KERNEL);
> + if (!tport) {
> + pr_err("Unable to allocate struct tcm_vhost_tport");
> + return ERR_PTR(-ENOMEM);
> + }
> + tport->tport_wwpn = wwpn;
> + /*
> + * Determine the emulated Protocol Identifier and Target Port Name
> + * based on the incoming configfs directory name.
> + */
> + ptr = strstr(name, "naa.");
> + if (ptr) {
> + tport->tport_proto_id = SCSI_PROTOCOL_SAS;
> + goto check_len;
> + }
> + ptr = strstr(name, "fc.");
> + if (ptr) {
> + tport->tport_proto_id = SCSI_PROTOCOL_FCP;
> + off = 3; /* Skip over "fc." */
> + goto check_len;
> + }
> + ptr = strstr(name, "iqn.");
> + if (ptr) {
> + tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
> + goto check_len;
> + }
> +
> + pr_err("Unable to locate prefix for emulated Target Port:"
> + " %s\n", name);
> + kfree(tport);
> + return ERR_PTR(-EINVAL);
> +
> +check_len:
> + if (strlen(name) >= TCM_VHOST_NAMELEN) {
> + pr_err("Emulated %s Address: %s, exceeds"
> + " max: %d\n", name, tcm_vhost_dump_proto_id(tport),
> + TCM_VHOST_NAMELEN);
> + kfree(tport);
> + return ERR_PTR(-EINVAL);
> + }
> + snprintf(&tport->tport_name[0], TCM_VHOST_NAMELEN, "%s", &name[off]);
> +
> + pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
> + " %s Address: %s\n", tcm_vhost_dump_proto_id(tport), name);
> +
> + return &tport->tport_wwn;
> +}
> +
> +static void tcm_vhost_drop_tport(struct se_wwn *wwn)
> +{
> + struct tcm_vhost_tport *tport = container_of(wwn,
> + struct tcm_vhost_tport, tport_wwn);
> +
> + pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
> + " %s Address: %s\n", tcm_vhost_dump_proto_id(tport),
> + tport->tport_name);
> +
> + kfree(tport);
> +}
> +
> +static ssize_t tcm_vhost_wwn_show_attr_version(
> + struct target_fabric_configfs *tf,
> + char *page)
> +{
> + return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
> + "on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
> + utsname()->machine);
> +}
> +
> +TF_WWN_ATTR_RO(tcm_vhost, version);
> +
> +static struct configfs_attribute *tcm_vhost_wwn_attrs[] = {
> + &tcm_vhost_wwn_version.attr,
> + NULL,
> +};
> +
> +static struct target_core_fabric_ops tcm_vhost_ops = {
> + .get_fabric_name = tcm_vhost_get_fabric_name,
> + .get_fabric_proto_ident = tcm_vhost_get_fabric_proto_ident,
> + .tpg_get_wwn = tcm_vhost_get_fabric_wwn,
> + .tpg_get_tag = tcm_vhost_get_tag,
> + .tpg_get_default_depth = tcm_vhost_get_default_depth,
> + .tpg_get_pr_transport_id = tcm_vhost_get_pr_transport_id,
> + .tpg_get_pr_transport_id_len = tcm_vhost_get_pr_transport_id_len,
> + .tpg_parse_pr_out_transport_id = tcm_vhost_parse_pr_out_transport_id,
> + .tpg_check_demo_mode = tcm_vhost_check_true,
> + .tpg_check_demo_mode_cache = tcm_vhost_check_true,
> + .tpg_check_demo_mode_write_protect = tcm_vhost_check_false,
> + .tpg_check_prod_mode_write_protect = tcm_vhost_check_false,
> + .tpg_alloc_fabric_acl = tcm_vhost_alloc_fabric_acl,
> + .tpg_release_fabric_acl = tcm_vhost_release_fabric_acl,
> + .tpg_get_inst_index = tcm_vhost_tpg_get_inst_index,
> + .release_cmd = tcm_vhost_release_cmd,
> + .shutdown_session = tcm_vhost_shutdown_session,
> + .close_session = tcm_vhost_close_session,
> + .sess_get_index = tcm_vhost_sess_get_index,
> + .sess_get_initiator_sid = NULL,
> + .write_pending = tcm_vhost_write_pending,
> + .write_pending_status = tcm_vhost_write_pending_status,
> + .set_default_node_attributes = tcm_vhost_set_default_node_attrs,
> + .get_task_tag = tcm_vhost_get_task_tag,
> + .get_cmd_state = tcm_vhost_get_cmd_state,
> + .queue_data_in = tcm_vhost_queue_data_in,
> + .queue_status = tcm_vhost_queue_status,
> + .queue_tm_rsp = tcm_vhost_queue_tm_rsp,
> + .get_fabric_sense_len = tcm_vhost_get_fabric_sense_len,
> + .set_fabric_sense_len = tcm_vhost_set_fabric_sense_len,
> + /*
> + * Setup callers for generic logic in target_core_fabric_configfs.c
> + */
> + .fabric_make_wwn = tcm_vhost_make_tport,
> + .fabric_drop_wwn = tcm_vhost_drop_tport,
> + .fabric_make_tpg = tcm_vhost_make_tpg,
> + .fabric_drop_tpg = tcm_vhost_drop_tpg,
> + .fabric_post_link = tcm_vhost_port_link,
> + .fabric_pre_unlink = tcm_vhost_port_unlink,
> + .fabric_make_np = NULL,
> + .fabric_drop_np = NULL,
> + .fabric_make_nodeacl = tcm_vhost_make_nodeacl,
> + .fabric_drop_nodeacl = tcm_vhost_drop_nodeacl,
> +};
> +
> +static int tcm_vhost_register_configfs(void)
> +{
> + struct target_fabric_configfs *fabric;
> + int ret;
> +
> + pr_debug("TCM_VHOST fabric module %s on %s/%s"
> + " on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
> + utsname()->machine);
> + /*
> + * Register the top level struct config_item_type with TCM core
> + */
> + fabric = target_fabric_configfs_init(THIS_MODULE, "vhost");
> + if (IS_ERR(fabric)) {
> + pr_err("target_fabric_configfs_init() failed\n");
> + return PTR_ERR(fabric);
> + }
> + /*
> + * Setup fabric->tf_ops from our local tcm_vhost_ops
> + */
> + fabric->tf_ops = tcm_vhost_ops;
> + /*
> + * Setup default attribute lists for various fabric->tf_cit_tmpl
> + */
> + TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_vhost_wwn_attrs;
> + TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_vhost_tpg_attrs;
> + TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_nacl_base_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
> + TF_CIT_TMPL(fabric)->tfc_tpg_nacl_param_cit.ct_attrs = NULL;
> + /*
> + * Register the fabric for use within TCM
> + */
> + ret = target_fabric_configfs_register(fabric);
> + if (ret < 0) {
> + pr_err("target_fabric_configfs_register() failed"
> + " for TCM_VHOST\n");
> + return ret;
> + }
> + /*
> + * Setup our local pointer to *fabric
> + */
> + tcm_vhost_fabric_configfs = fabric;
> + pr_debug("TCM_VHOST[0] - Set fabric -> tcm_vhost_fabric_configfs\n");
> + return 0;
> +};
> +
> +static void tcm_vhost_deregister_configfs(void)
> +{
> + if (!tcm_vhost_fabric_configfs)
> + return;
> +
> + target_fabric_configfs_deregister(tcm_vhost_fabric_configfs);
> + tcm_vhost_fabric_configfs = NULL;
> + pr_debug("TCM_VHOST[0] - Cleared tcm_vhost_fabric_configfs\n");
> +};
> +
> +static int __init tcm_vhost_init(void)
> +{
> + int ret = -ENOMEM;
> +
> + tcm_vhost_workqueue = alloc_workqueue("tcm_vhost", 0, 0);
> + if (!tcm_vhost_workqueue)
> + goto out;
Pls add a comment explaining why we need our own workqueue
and aren't using the system one instead.
> +
> + ret = vhost_scsi_register();
> + if (ret < 0)
> + goto out_destroy_workqueue;
> +
> + ret = tcm_vhost_register_configfs();
> + if (ret < 0)
> + goto out_vhost_scsi_deregister;
> +
> + return 0;
> +
> +out_vhost_scsi_deregister:
> + vhost_scsi_deregister();
> +out_destroy_workqueue:
> + destroy_workqueue(tcm_vhost_workqueue);
> +out:
> + return ret;
> +};
> +
> +static void tcm_vhost_exit(void)
> +{
> + tcm_vhost_deregister_configfs();
> + vhost_scsi_deregister();
> + destroy_workqueue(tcm_vhost_workqueue);
> +};
> +
> +MODULE_DESCRIPTION("TCM_VHOST series fabric driver");
> +MODULE_LICENSE("GPL");
> +module_init(tcm_vhost_init);
> +module_exit(tcm_vhost_exit);
> diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
> new file mode 100644
> index 0000000..c983ed2
> --- /dev/null
> +++ b/drivers/vhost/tcm_vhost.h
> @@ -0,0 +1,101 @@
> +#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;
> + /* 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;
> + /* 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 list_head 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 */
> + atomic_t tv_tpg_port_count;
> + /* Used for vhost_scsi device reference to tpg_nexus */
> + atomic_t 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;
would it be easier to just use dev mutex instead?
> + /* 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
> + */
> +
> +#define VHOST_SCSI_ABI_VERSION 0
> +
> +struct vhost_scsi_target {
> + int abi_version;
> + unsigned char vhost_wwpn[TRANSPORT_IQN_LEN];
> + unsigned short vhost_tpgt;
> +};
> +
> +/* 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)
> +#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, struct
> vhost_scsi_target)
CLEAR_ENDPOINT and SET_ENDPOINT commands get an abi version
too but it's ignored there. Intentional?
Why not
#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
and then you avoid changing vhost_scsi_target ...
Also, let's add a comment like
/* Changing this breaks userspace. */
so we remember never to change this value.
> --
> 1.7.2.5