diff options
Diffstat (limited to 'drivers/xen/xen-scsiback.c')
| -rw-r--r-- | drivers/xen/xen-scsiback.c | 1910 |
1 files changed, 1910 insertions, 0 deletions
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c new file mode 100644 index 000000000..614d067ff --- /dev/null +++ b/drivers/xen/xen-scsiback.c @@ -0,0 +1,1910 @@ +/* + * Xen SCSI backend driver + * + * Copyright (c) 2008, FUJITSU Limited + * + * Based on the blkback driver code. + * Adaption to kernel taget core infrastructure taken from vhost/scsi.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#define pr_fmt(fmt) "xen-pvscsi: " fmt + +#include <stdarg.h> + +#include <linux/module.h> +#include <linux/utsname.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/list.h> +#include <linux/gfp.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/configfs.h> + +#include <generated/utsrelease.h> + +#include <scsi/scsi_host.h> /* SG_ALL */ + +#include <target/target_core_base.h> +#include <target/target_core_fabric.h> + +#include <asm/hypervisor.h> + +#include <xen/xen.h> +#include <xen/balloon.h> +#include <xen/events.h> +#include <xen/xenbus.h> +#include <xen/grant_table.h> +#include <xen/page.h> + +#include <xen/interface/grant_table.h> +#include <xen/interface/io/vscsiif.h> + +#define VSCSI_VERSION "v0.1" +#define VSCSI_NAMELEN 32 + +struct ids_tuple { + unsigned int hst; /* host */ + unsigned int chn; /* channel */ + unsigned int tgt; /* target */ + unsigned int lun; /* LUN */ +}; + +struct v2p_entry { + struct ids_tuple v; /* translate from */ + struct scsiback_tpg *tpg; /* translate to */ + unsigned int lun; + struct kref kref; + struct list_head l; +}; + +struct vscsibk_info { + struct xenbus_device *dev; + + domid_t domid; + unsigned int irq; + + struct vscsiif_back_ring ring; + + spinlock_t ring_lock; + atomic_t nr_unreplied_reqs; + + spinlock_t v2p_lock; + struct list_head v2p_entry_lists; + + wait_queue_head_t waiting_to_free; +}; + +/* theoretical maximum of grants for one request */ +#define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE) + +/* + * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one + * call to map/unmap grants. Don't choose it too large, as there are arrays + * with VSCSI_GRANT_BATCH elements allocated on the stack. + */ +#define VSCSI_GRANT_BATCH 16 + +struct vscsibk_pend { + uint16_t rqid; + + uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE]; + uint8_t cmd_len; + + uint8_t sc_data_direction; + uint16_t n_sg; /* real length of SG list */ + uint16_t n_grants; /* SG pages and potentially SG list */ + uint32_t data_len; + uint32_t result; + + struct vscsibk_info *info; + struct v2p_entry *v2p; + struct scatterlist *sgl; + + uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE]; + + grant_handle_t grant_handles[VSCSI_MAX_GRANTS]; + struct page *pages[VSCSI_MAX_GRANTS]; + + struct se_cmd se_cmd; + + struct completion tmr_done; +}; + +#define VSCSI_DEFAULT_SESSION_TAGS 128 + +struct scsiback_nexus { + /* Pointer to TCM session for I_T Nexus */ + struct se_session *tvn_se_sess; +}; + +struct scsiback_tport { + /* SCSI protocol the tport is providing */ + u8 tport_proto_id; + /* Binary World Wide unique Port Name for pvscsi Target port */ + u64 tport_wwpn; + /* ASCII formatted WWPN for pvscsi Target port */ + char tport_name[VSCSI_NAMELEN]; + /* Returned by scsiback_make_tport() */ + struct se_wwn tport_wwn; +}; + +struct scsiback_tpg { + /* scsiback port target portal group tag for TCM */ + u16 tport_tpgt; + /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */ + int tv_tpg_port_count; + /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */ + int tv_tpg_fe_count; + /* list for scsiback_list */ + struct list_head tv_tpg_list; + /* Used to protect access for tpg_nexus */ + struct mutex tv_tpg_mutex; + /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */ + struct scsiback_nexus *tpg_nexus; + /* Pointer back to scsiback_tport */ + struct scsiback_tport *tport; + /* Returned by scsiback_make_tpg() */ + struct se_portal_group se_tpg; + /* alias used in xenstore */ + char param_alias[VSCSI_NAMELEN]; + /* list of info structures related to this target portal group */ + struct list_head info_list; +}; + +#define SCSIBACK_INVALID_HANDLE (~0) + +static bool log_print_stat; +module_param(log_print_stat, bool, 0644); + +static int scsiback_max_buffer_pages = 1024; +module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644); +MODULE_PARM_DESC(max_buffer_pages, +"Maximum number of free pages to keep in backend buffer"); + +static DEFINE_SPINLOCK(free_pages_lock); +static int free_pages_num; +static LIST_HEAD(scsiback_free_pages); + +/* Global spinlock to protect scsiback TPG list */ +static DEFINE_MUTEX(scsiback_mutex); +static LIST_HEAD(scsiback_list); + +static void scsiback_get(struct vscsibk_info *info) +{ + atomic_inc(&info->nr_unreplied_reqs); +} + +static void scsiback_put(struct vscsibk_info *info) +{ + if (atomic_dec_and_test(&info->nr_unreplied_reqs)) + wake_up(&info->waiting_to_free); +} + +static void put_free_pages(struct page **page, int num) +{ + unsigned long flags; + int i = free_pages_num + num, n = num; + + if (num == 0) + return; + if (i > scsiback_max_buffer_pages) { + n = min(num, i - scsiback_max_buffer_pages); + gnttab_free_pages(n, page + num - n); + n = num - n; + } + spin_lock_irqsave(&free_pages_lock, flags); + for (i = 0; i < n; i++) + list_add(&page[i]->lru, &scsiback_free_pages); + free_pages_num += n; + spin_unlock_irqrestore(&free_pages_lock, flags); +} + +static int get_free_page(struct page **page) +{ + unsigned long flags; + + spin_lock_irqsave(&free_pages_lock, flags); + if (list_empty(&scsiback_free_pages)) { + spin_unlock_irqrestore(&free_pages_lock, flags); + return gnttab_alloc_pages(1, page); + } + page[0] = list_first_entry(&scsiback_free_pages, struct page, lru); + list_del(&page[0]->lru); + free_pages_num--; + spin_unlock_irqrestore(&free_pages_lock, flags); + return 0; +} + +static unsigned long vaddr_page(struct page *page) +{ + unsigned long pfn = page_to_pfn(page); + + return (unsigned long)pfn_to_kaddr(pfn); +} + +static unsigned long vaddr(struct vscsibk_pend *req, int seg) +{ + return vaddr_page(req->pages[seg]); +} + +static void scsiback_print_status(char *sense_buffer, int errors, + struct vscsibk_pend *pending_req) +{ + struct scsiback_tpg *tpg = pending_req->v2p->tpg; + + pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n", + tpg->tport->tport_name, pending_req->v2p->lun, + pending_req->cmnd[0], status_byte(errors), msg_byte(errors), + host_byte(errors), driver_byte(errors)); +} + +static void scsiback_fast_flush_area(struct vscsibk_pend *req) +{ + struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH]; + struct page *pages[VSCSI_GRANT_BATCH]; + unsigned int i, invcount = 0; + grant_handle_t handle; + int err; + + kfree(req->sgl); + req->sgl = NULL; + req->n_sg = 0; + + if (!req->n_grants) + return; + + for (i = 0; i < req->n_grants; i++) { + handle = req->grant_handles[i]; + if (handle == SCSIBACK_INVALID_HANDLE) + continue; + gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), + GNTMAP_host_map, handle); + req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; + pages[invcount] = req->pages[i]; + put_page(pages[invcount]); + invcount++; + if (invcount < VSCSI_GRANT_BATCH) + continue; + err = gnttab_unmap_refs(unmap, NULL, pages, invcount); + BUG_ON(err); + invcount = 0; + } + + if (invcount) { + err = gnttab_unmap_refs(unmap, NULL, pages, invcount); + BUG_ON(err); + } + + put_free_pages(req->pages, req->n_grants); + req->n_grants = 0; +} + +static void scsiback_free_translation_entry(struct kref *kref) +{ + struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref); + struct scsiback_tpg *tpg = entry->tpg; + + mutex_lock(&tpg->tv_tpg_mutex); + tpg->tv_tpg_fe_count--; + mutex_unlock(&tpg->tv_tpg_mutex); + + kfree(entry); +} + +static void scsiback_send_response(struct vscsibk_info *info, + char *sense_buffer, int32_t result, uint32_t resid, + uint16_t rqid) +{ + struct vscsiif_response *ring_res; + int notify; + struct scsi_sense_hdr sshdr; + unsigned long flags; + unsigned len; + + spin_lock_irqsave(&info->ring_lock, flags); + + ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); + info->ring.rsp_prod_pvt++; + + ring_res->rslt = result; + ring_res->rqid = rqid; + + if (sense_buffer != NULL && + scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, + &sshdr)) { + len = min_t(unsigned, 8 + sense_buffer[7], + VSCSIIF_SENSE_BUFFERSIZE); + memcpy(ring_res->sense_buffer, sense_buffer, len); + ring_res->sense_len = len; + } else { + ring_res->sense_len = 0; + } + + ring_res->residual_len = resid; + + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); + spin_unlock_irqrestore(&info->ring_lock, flags); + + if (notify) + notify_remote_via_irq(info->irq); +} + +static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, + uint32_t resid, struct vscsibk_pend *pending_req) +{ + scsiback_send_response(pending_req->info, sense_buffer, result, + resid, pending_req->rqid); + + if (pending_req->v2p) + kref_put(&pending_req->v2p->kref, + scsiback_free_translation_entry); +} + +static void scsiback_cmd_done(struct vscsibk_pend *pending_req) +{ + struct vscsibk_info *info = pending_req->info; + unsigned char *sense_buffer; + unsigned int resid; + int errors; + + sense_buffer = pending_req->sense_buffer; + resid = pending_req->se_cmd.residual_count; + errors = pending_req->result; + + if (errors && log_print_stat) + scsiback_print_status(sense_buffer, errors, pending_req); + + scsiback_fast_flush_area(pending_req); + scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); + scsiback_put(info); + /* + * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls() + * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd() + * final se_cmd->cmd_kref put. + */ + target_put_sess_cmd(&pending_req->se_cmd); +} + +static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) +{ + struct se_cmd *se_cmd = &pending_req->se_cmd; + struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; + int rc; + + scsiback_get(pending_req->info); + se_cmd->tag = pending_req->rqid; + rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd, + pending_req->sense_buffer, pending_req->v2p->lun, + pending_req->data_len, 0, + pending_req->sc_data_direction, TARGET_SCF_ACK_KREF, + pending_req->sgl, pending_req->n_sg, + NULL, 0, NULL, 0); + if (rc < 0) { + transport_send_check_condition_and_sense(se_cmd, + TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0); + transport_generic_free_cmd(se_cmd, 0); + } +} + +static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, + struct page **pg, grant_handle_t *grant, int cnt) +{ + int err, i; + + if (!cnt) + return 0; + + err = gnttab_map_refs(map, NULL, pg, cnt); + for (i = 0; i < cnt; i++) { + if (unlikely(map[i].status != GNTST_okay)) { + pr_err("invalid buffer -- could not remap it\n"); + map[i].handle = SCSIBACK_INVALID_HANDLE; + if (!err) + err = -ENOMEM; + } else { + get_page(pg[i]); + } + grant[i] = map[i].handle; + } + return err; +} + +static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, + struct scsiif_request_segment *seg, struct page **pg, + grant_handle_t *grant, int cnt, u32 flags) +{ + int mapcount = 0, i, err = 0; + struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; + struct vscsibk_info *info = pending_req->info; + + for (i = 0; i < cnt; i++) { + if (get_free_page(pg + mapcount)) { + put_free_pages(pg, mapcount); + pr_err("no grant page\n"); + return -ENOMEM; + } + gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), + flags, seg[i].gref, info->domid); + mapcount++; + if (mapcount < VSCSI_GRANT_BATCH) + continue; + err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); + pg += mapcount; + grant += mapcount; + pending_req->n_grants += mapcount; + if (err) + return err; + mapcount = 0; + } + err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); + pending_req->n_grants += mapcount; + return err; +} + +static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, + struct vscsibk_pend *pending_req) +{ + u32 flags; + int i, err, n_segs, i_seg = 0; + struct page **pg; + struct scsiif_request_segment *seg; + unsigned long end_seg = 0; + unsigned int nr_segments = (unsigned int)ring_req->nr_segments; + unsigned int nr_sgl = 0; + struct scatterlist *sg; + grant_handle_t *grant; + + pending_req->n_sg = 0; + pending_req->n_grants = 0; + pending_req->data_len = 0; + + nr_segments &= ~VSCSIIF_SG_GRANT; + if (!nr_segments) + return 0; + + if (nr_segments > VSCSIIF_SG_TABLESIZE) { + pr_debug("invalid parameter nr_seg = %d\n", + ring_req->nr_segments); + return -EINVAL; + } + + if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { + err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, + pending_req->pages, pending_req->grant_handles, + nr_segments, GNTMAP_host_map | GNTMAP_readonly); + if (err) + return err; + nr_sgl = nr_segments; + nr_segments = 0; + for (i = 0; i < nr_sgl; i++) { + n_segs = ring_req->seg[i].length / + sizeof(struct scsiif_request_segment); + if ((unsigned)ring_req->seg[i].offset + + (unsigned)ring_req->seg[i].length > PAGE_SIZE || + n_segs * sizeof(struct scsiif_request_segment) != + ring_req->seg[i].length) + return -EINVAL; + nr_segments += n_segs; + } + if (nr_segments > SG_ALL) { + pr_debug("invalid nr_seg = %d\n", nr_segments); + return -EINVAL; + } + } + + /* free of (sgl) in fast_flush_area() */ + pending_req->sgl = kmalloc_array(nr_segments, + sizeof(struct scatterlist), GFP_KERNEL); + if (!pending_req->sgl) + return -ENOMEM; + + sg_init_table(pending_req->sgl, nr_segments); + pending_req->n_sg = nr_segments; + + flags = GNTMAP_host_map; + if (pending_req->sc_data_direction == DMA_TO_DEVICE) + flags |= GNTMAP_readonly; + + pg = pending_req->pages + nr_sgl; + grant = pending_req->grant_handles + nr_sgl; + if (!nr_sgl) { + seg = ring_req->seg; + err = scsiback_gnttab_data_map_list(pending_req, seg, + pg, grant, nr_segments, flags); + if (err) + return err; + } else { + for (i = 0; i < nr_sgl; i++) { + seg = (struct scsiif_request_segment *)( + vaddr(pending_req, i) + ring_req->seg[i].offset); + n_segs = ring_req->seg[i].length / + sizeof(struct scsiif_request_segment); + err = scsiback_gnttab_data_map_list(pending_req, seg, + pg, grant, n_segs, flags); + if (err) + return err; + pg += n_segs; + grant += n_segs; + } + end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; + seg = (struct scsiif_request_segment *)end_seg; + end_seg += ring_req->seg[0].length; + pg = pending_req->pages + nr_sgl; + } + + for_each_sg(pending_req->sgl, sg, nr_segments, i) { + sg_set_page(sg, pg[i], seg->length, seg->offset); + pending_req->data_len += seg->length; + seg++; + if (nr_sgl && (unsigned long)seg >= end_seg) { + i_seg++; + end_seg = vaddr(pending_req, i_seg) + + ring_req->seg[i_seg].offset; + seg = (struct scsiif_request_segment *)end_seg; + end_seg += ring_req->seg[i_seg].length; + } + if (sg->offset >= PAGE_SIZE || + sg->length > PAGE_SIZE || + sg->offset + sg->length > PAGE_SIZE) + return -EINVAL; + } + + return 0; +} + +static void scsiback_disconnect(struct vscsibk_info *info) +{ + wait_event(info->waiting_to_free, + atomic_read(&info->nr_unreplied_reqs) == 0); + + unbind_from_irqhandler(info->irq, info); + info->irq = 0; + xenbus_unmap_ring_vfree(info->dev, info->ring.sring); +} + +static void scsiback_device_action(struct vscsibk_pend *pending_req, + enum tcm_tmreq_table act, int tag) +{ + struct scsiback_tpg *tpg = pending_req->v2p->tpg; + struct scsiback_nexus *nexus = tpg->tpg_nexus; + struct se_cmd *se_cmd = &pending_req->se_cmd; + u64 unpacked_lun = pending_req->v2p->lun; + int rc, err = FAILED; + + init_completion(&pending_req->tmr_done); + + rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, + &pending_req->sense_buffer[0], + unpacked_lun, NULL, act, GFP_KERNEL, + tag, TARGET_SCF_ACK_KREF); + if (rc) + goto err; + + wait_for_completion(&pending_req->tmr_done); + + err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? + SUCCESS : FAILED; + + scsiback_do_resp_with_sense(NULL, err, 0, pending_req); + transport_generic_free_cmd(&pending_req->se_cmd, 0); + return; + +err: + scsiback_do_resp_with_sense(NULL, err, 0, pending_req); +} + +/* + Perform virtual to physical translation +*/ +static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, + struct ids_tuple *v) +{ + struct v2p_entry *entry; + struct list_head *head = &(info->v2p_entry_lists); + unsigned long flags; + + spin_lock_irqsave(&info->v2p_lock, flags); + list_for_each_entry(entry, head, l) { + if ((entry->v.chn == v->chn) && + (entry->v.tgt == v->tgt) && + (entry->v.lun == v->lun)) { + kref_get(&entry->kref); + goto out; + } + } + entry = NULL; + +out: + spin_unlock_irqrestore(&info->v2p_lock, flags); + return entry; +} + +static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, + struct v2p_entry *v2p) +{ + struct scsiback_tpg *tpg = v2p->tpg; + struct scsiback_nexus *nexus = tpg->tpg_nexus; + struct se_session *se_sess = nexus->tvn_se_sess; + struct vscsibk_pend *req; + int tag, cpu, i; + + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); + if (tag < 0) { + pr_err("Unable to obtain tag for vscsiif_request\n"); + return ERR_PTR(-ENOMEM); + } + + req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; + memset(req, 0, sizeof(*req)); + req->se_cmd.map_tag = tag; + req->se_cmd.map_cpu = cpu; + + for (i = 0; i < VSCSI_MAX_GRANTS; i++) + req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; + + return req; +} + +static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, + struct vscsiif_back_ring *ring, + struct vscsiif_request *ring_req) +{ + struct vscsibk_pend *pending_req; + struct v2p_entry *v2p; + struct ids_tuple vir; + + /* request range check from frontend */ + if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && + (ring_req->sc_data_direction != DMA_TO_DEVICE) && + (ring_req->sc_data_direction != DMA_FROM_DEVICE) && + (ring_req->sc_data_direction != DMA_NONE)) { + pr_debug("invalid parameter data_dir = %d\n", + ring_req->sc_data_direction); + return ERR_PTR(-EINVAL); + } + if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { + pr_debug("invalid parameter cmd_len = %d\n", + ring_req->cmd_len); + return ERR_PTR(-EINVAL); + } + + vir.chn = ring_req->channel; + vir.tgt = ring_req->id; + vir.lun = ring_req->lun; + + v2p = scsiback_do_translation(info, &vir); + if (!v2p) { + pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", + vir.chn, vir.tgt, vir.lun); + return ERR_PTR(-ENODEV); + } + + pending_req = scsiback_get_pend_req(ring, v2p); + if (IS_ERR(pending_req)) { + kref_put(&v2p->kref, scsiback_free_translation_entry); + return ERR_PTR(-ENOMEM); + } + pending_req->rqid = ring_req->rqid; + pending_req->info = info; + pending_req->v2p = v2p; + pending_req->sc_data_direction = ring_req->sc_data_direction; + pending_req->cmd_len = ring_req->cmd_len; + memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); + + return pending_req; +} + +static int scsiback_do_cmd_fn(struct vscsibk_info *info, + unsigned int *eoi_flags) +{ + struct vscsiif_back_ring *ring = &info->ring; + struct vscsiif_request ring_req; + struct vscsibk_pend *pending_req; + RING_IDX rc, rp; + int more_to_do; + uint32_t result; + + rc = ring->req_cons; + rp = ring->sring->req_prod; + rmb(); /* guest system is accessing ring, too */ + + if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { + rc = ring->rsp_prod_pvt; + pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", + info->domid, rp, rc, rp - rc); + return -EINVAL; + } + + while ((rc != rp)) { + *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS; + + if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) + break; + + RING_COPY_REQUEST(ring, rc, &ring_req); + ring->req_cons = ++rc; + + pending_req = prepare_pending_reqs(info, ring, &ring_req); + if (IS_ERR(pending_req)) { + switch (PTR_ERR(pending_req)) { + case -ENODEV: + result = DID_NO_CONNECT; + break; + default: + result = DRIVER_ERROR; + break; + } + scsiback_send_response(info, NULL, result << 24, 0, + ring_req.rqid); + return 1; + } + + switch (ring_req.act) { + case VSCSIIF_ACT_SCSI_CDB: + if (scsiback_gnttab_data_map(&ring_req, pending_req)) { + scsiback_fast_flush_area(pending_req); + scsiback_do_resp_with_sense(NULL, + DRIVER_ERROR << 24, 0, pending_req); + transport_generic_free_cmd(&pending_req->se_cmd, 0); + } else { + scsiback_cmd_exec(pending_req); + } + break; + case VSCSIIF_ACT_SCSI_ABORT: + scsiback_device_action(pending_req, TMR_ABORT_TASK, + ring_req.ref_rqid); + break; + case VSCSIIF_ACT_SCSI_RESET: + scsiback_device_action(pending_req, TMR_LUN_RESET, 0); + break; + default: + pr_err_ratelimited("invalid request\n"); + scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0, + pending_req); + transport_generic_free_cmd(&pending_req->se_cmd, 0); + break; + } + + /* Yield point for this unbounded loop. */ + cond_resched(); + } + + RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); + return more_to_do; +} + +static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) +{ + struct vscsibk_info *info = dev_id; + int rc; + unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; + + while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0) + cond_resched(); + + /* In case of a ring error we keep the event channel masked. */ + if (!rc) + xen_irq_lateeoi(irq, eoi_flags); + + return IRQ_HANDLED; +} + +static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, + evtchn_port_t evtchn) +{ + void *area; + struct vscsiif_sring *sring; + int err; + + if (info->irq) + return -1; + + err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); + if (err) + return err; + + sring = (struct vscsiif_sring *)area; + BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); + + err = bind_interdomain_evtchn_to_irq_lateeoi(info->domid, evtchn); + if (err < 0) + goto unmap_page; + + info->irq = err; + + err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, + IRQF_ONESHOT, "vscsiif-backend", info); + if (err) + goto free_irq; + + return 0; + +free_irq: + unbind_from_irqhandler(info->irq, info); + info->irq = 0; +unmap_page: + xenbus_unmap_ring_vfree(info->dev, area); + + return err; +} + +static int scsiback_map(struct vscsibk_info *info) +{ + struct xenbus_device *dev = info->dev; + unsigned int ring_ref, evtchn; + int err; + + err = xenbus_gather(XBT_NIL, dev->otherend, + "ring-ref", "%u", &ring_ref, + "event-channel", "%u", &evtchn, NULL); + if (err) { + xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); + return err; + } + + return scsiback_init_sring(info, ring_ref, evtchn); +} + +/* + Check for a translation entry being present +*/ +static struct v2p_entry *scsiback_chk_translation_entry( + struct vscsibk_info *info, struct ids_tuple *v) +{ + struct list_head *head = &(info->v2p_entry_lists); + struct v2p_entry *entry; + + list_for_each_entry(entry, head, l) + if ((entry->v.chn == v->chn) && + (entry->v.tgt == v->tgt) && + (entry->v.lun == v->lun)) + return entry; + + return NULL; +} + +/* + Add a new translation entry +*/ +static int scsiback_add_translation_entry(struct vscsibk_info *info, + char *phy, struct ids_tuple *v) +{ + int err = 0; + struct v2p_entry *new; + unsigned long flags; + char *lunp; + unsigned long long unpacked_lun; + struct se_lun *se_lun; + struct scsiback_tpg *tpg_entry, *tpg = NULL; + char *error = "doesn't exist"; + + lunp = strrchr(phy, ':'); + if (!lunp) { + pr_err("illegal format of physical device %s\n", phy); + return -EINVAL; + } + *lunp = 0; + lunp++; + err = kstrtoull(lunp, 10, &unpacked_lun); + if (err < 0) { + pr_err("lun number not valid: %s\n", lunp); + return err; + } + + mutex_lock(&scsiback_mutex); + list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { + if (!strcmp(phy, tpg_entry->tport->tport_name) || + !strcmp(phy, tpg_entry->param_alias)) { + mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); + hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { + if (se_lun->unpacked_lun == unpacked_lun) { + if (!tpg_entry->tpg_nexus) + error = "nexus undefined"; + else + tpg = tpg_entry; + break; + } + } + mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); + break; + } + } + if (tpg) { + mutex_lock(&tpg->tv_tpg_mutex); + tpg->tv_tpg_fe_count++; + mutex_unlock(&tpg->tv_tpg_mutex); + } + mutex_unlock(&scsiback_mutex); + + if (!tpg) { + pr_err("%s:%llu %s\n", phy, unpacked_lun, error); + return -ENODEV; + } + + new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); + if (new == NULL) { + err = -ENOMEM; + goto out_free; + } + + spin_lock_irqsave(&info->v2p_lock, flags); + + /* Check double assignment to identical virtual ID */ + if (scsiback_chk_translation_entry(info, v)) { + pr_warn("Virtual ID is already used. Assignment was not performed.\n"); + err = -EEXIST; + goto out; + } + + /* Create a new translation entry and add to the list */ + kref_init(&new->kref); + new->v = *v; + new->tpg = tpg; + new->lun = unpacked_lun; + list_add_tail(&new->l, &info->v2p_entry_lists); + +out: + spin_unlock_irqrestore(&info->v2p_lock, flags); + +out_free: + if (err) { + mutex_lock(&tpg->tv_tpg_mutex); + tpg->tv_tpg_fe_count--; + mutex_unlock(&tpg->tv_tpg_mutex); + kfree(new); + } + + return err; +} + +static void __scsiback_del_translation_entry(struct v2p_entry *entry) +{ + list_del(&entry->l); + kref_put(&entry->kref, scsiback_free_translation_entry); +} + +/* + Delete the translation entry specified +*/ +static int scsiback_del_translation_entry(struct vscsibk_info *info, + struct ids_tuple *v) +{ + struct v2p_entry *entry; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&info->v2p_lock, flags); + /* Find out the translation entry specified */ + entry = scsiback_chk_translation_entry(info, v); + if (entry) + __scsiback_del_translation_entry(entry); + else + ret = -ENOENT; + + spin_unlock_irqrestore(&info->v2p_lock, flags); + return ret; +} + +static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, + char *phy, struct ids_tuple *vir, int try) +{ + struct v2p_entry *entry; + unsigned long flags; + int err; + + if (try) { + spin_lock_irqsave(&info->v2p_lock, flags); + entry = scsiback_chk_translation_entry(info, vir); + spin_unlock_irqrestore(&info->v2p_lock, flags); + if (entry) + return; + } + if (!scsiback_add_translation_entry(info, phy, vir)) { + if (xenbus_printf(XBT_NIL, info->dev->nodename, state, + "%d", XenbusStateInitialised)) { + pr_err("xenbus_printf error %s\n", state); + scsiback_del_translation_entry(info, vir); + } + } else if (!try) { + err = xenbus_printf(XBT_NIL, info->dev->nodename, state, + "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); + } +} + +static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, + struct ids_tuple *vir) +{ + if (!scsiback_del_translation_entry(info, vir)) { + if (xenbus_printf(XBT_NIL, info->dev->nodename, state, + "%d", XenbusStateClosed)) + pr_err("xenbus_printf error %s\n", state); + } +} + +#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 +#define VSCSIBACK_OP_UPDATEDEV_STATE 2 + +static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, + char *ent) +{ + int err; + struct ids_tuple vir; + char *val; + int device_state; + char phy[VSCSI_NAMELEN]; + char str[64]; + char state[64]; + struct xenbus_device *dev = info->dev; + + /* read status */ + snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); + err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); + if (XENBUS_EXIST_ERR(err)) + return; + + /* physical SCSI device */ + snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); + val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); + if (IS_ERR(val)) { + err = xenbus_printf(XBT_NIL, dev->nodename, state, + "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); + return; + } + strlcpy(phy, val, VSCSI_NAMELEN); + kfree(val); + + /* virtual SCSI device */ + snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); + err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", + &vir.hst, &vir.chn, &vir.tgt, &vir.lun); + if (XENBUS_EXIST_ERR(err)) { + err = xenbus_printf(XBT_NIL, dev->nodename, state, + "%d", XenbusStateClosed); + if (err) + xenbus_dev_error(info->dev, err, + "%s: writing %s", __func__, state); + return; + } + + switch (op) { + case VSCSIBACK_OP_ADD_OR_DEL_LUN: + switch (device_state) { + case XenbusStateInitialising: + scsiback_do_add_lun(info, state, phy, &vir, 0); + break; + case XenbusStateConnected: + scsiback_do_add_lun(info, state, phy, &vir, 1); + break; + case XenbusStateClosing: + scsiback_do_del_lun(info, state, &vir); + break; + default: + break; + } + break; + + case VSCSIBACK_OP_UPDATEDEV_STATE: + if (device_state == XenbusStateInitialised) { + /* modify vscsi-devs/dev-x/state */ + if (xenbus_printf(XBT_NIL, dev->nodename, state, + "%d", XenbusStateConnected)) { + pr_err("xenbus_printf error %s\n", str); + scsiback_del_translation_entry(info, &vir); + xenbus_printf(XBT_NIL, dev->nodename, state, + "%d", XenbusStateClosed); + } + } + break; + /* When it is necessary, processing is added here. */ + default: + break; + } +} + +static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) +{ + int i; + char **dir; + unsigned int ndir = 0; + + dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", + &ndir); + if (IS_ERR(dir)) + return; + + for (i = 0; i < ndir; i++) + scsiback_do_1lun_hotplug(info, op, dir[i]); + + kfree(dir); +} + +static void scsiback_frontend_changed(struct xenbus_device *dev, + enum xenbus_state frontend_state) +{ + struct vscsibk_info *info = dev_get_drvdata(&dev->dev); + + switch (frontend_state) { + case XenbusStateInitialising: + break; + + case XenbusStateInitialised: + if (scsiback_map(info)) + break; + + scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateConnected: + scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); + + if (dev->state == XenbusStateConnected) + break; + + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateClosing: + if (info->irq) + scsiback_disconnect(info); + + xenbus_switch_state(dev, XenbusStateClosing); + break; + + case XenbusStateClosed: + xenbus_switch_state(dev, XenbusStateClosed); + if (xenbus_dev_is_online(dev)) + break; + /* fall through if not online */ + case XenbusStateUnknown: + device_unregister(&dev->dev); + break; + + case XenbusStateReconfiguring: + scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); + xenbus_switch_state(dev, XenbusStateReconfigured); + + break; + + default: + xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", + frontend_state); + break; + } +} + +/* + Release the translation entry specfied +*/ +static void scsiback_release_translation_entry(struct vscsibk_info *info) +{ + struct v2p_entry *entry, *tmp; + struct list_head *head = &(info->v2p_entry_lists); + unsigned long flags; + + spin_lock_irqsave(&info->v2p_lock, flags); + + list_for_each_entry_safe(entry, tmp, head, l) + __scsiback_del_translation_entry(entry); + + spin_unlock_irqrestore(&info->v2p_lock, flags); +} + +static int scsiback_remove(struct xenbus_device *dev) +{ + struct vscsibk_info *info = dev_get_drvdata(&dev->dev); + + if (info->irq) + scsiback_disconnect(info); + + scsiback_release_translation_entry(info); + + dev_set_drvdata(&dev->dev, NULL); + + return 0; +} + +static int scsiback_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + int err; + + struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), + GFP_KERNEL); + + pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); + + if (!info) { + xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); + return -ENOMEM; + } + info->dev = dev; + dev_set_drvdata(&dev->dev, info); + + info->domid = dev->otherend_id; + spin_lock_init(&info->ring_lock); + atomic_set(&info->nr_unreplied_reqs, 0); + init_waitqueue_head(&info->waiting_to_free); + info->dev = dev; + info->irq = 0; + INIT_LIST_HEAD(&info->v2p_entry_lists); + spin_lock_init(&info->v2p_lock); + + err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", + SG_ALL); + if (err) + xenbus_dev_error(dev, err, "writing feature-sg-grant"); + + err = xenbus_switch_state(dev, XenbusStateInitWait); + if (err) + goto fail; + + return 0; + +fail: + pr_warn("%s failed\n", __func__); + scsiback_remove(dev); + + return err; +} + +static char *scsiback_dump_proto_id(struct scsiback_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 char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + struct scsiback_tport *tport = tpg->tport; + + return &tport->tport_name[0]; +} + +static u16 scsiback_get_tag(struct se_portal_group *se_tpg) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + return tpg->tport_tpgt; +} + +static struct se_wwn * +scsiback_make_tport(struct target_fabric_configfs *tf, + struct config_group *group, + const char *name) +{ + struct scsiback_tport *tport; + char *ptr; + u64 wwpn = 0; + int off = 0; + + tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); + if (!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) >= VSCSI_NAMELEN) { + pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, + scsiback_dump_proto_id(tport), VSCSI_NAMELEN); + kfree(tport); + return ERR_PTR(-EINVAL); + } + snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); + + pr_debug("Allocated emulated Target %s Address: %s\n", + scsiback_dump_proto_id(tport), name); + + return &tport->tport_wwn; +} + +static void scsiback_drop_tport(struct se_wwn *wwn) +{ + struct scsiback_tport *tport = container_of(wwn, + struct scsiback_tport, tport_wwn); + + pr_debug("Deallocating emulated Target %s Address: %s\n", + scsiback_dump_proto_id(tport), tport->tport_name); + + kfree(tport); +} + +static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) +{ + return 1; +} + +static int scsiback_check_stop_free(struct se_cmd *se_cmd) +{ + return transport_generic_free_cmd(se_cmd, 0); +} + +static void scsiback_release_cmd(struct se_cmd *se_cmd) +{ + target_free_tag(se_cmd->se_sess, se_cmd); +} + +static u32 scsiback_sess_get_index(struct se_session *se_sess) +{ + return 0; +} + +static int scsiback_write_pending(struct se_cmd *se_cmd) +{ + /* Go ahead and process the write immediately */ + target_execute_cmd(se_cmd); + + return 0; +} + +static int scsiback_write_pending_status(struct se_cmd *se_cmd) +{ + return 0; +} + +static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) +{ +} + +static int scsiback_get_cmd_state(struct se_cmd *se_cmd) +{ + return 0; +} + +static int scsiback_queue_data_in(struct se_cmd *se_cmd) +{ + struct vscsibk_pend *pending_req = container_of(se_cmd, + struct vscsibk_pend, se_cmd); + + pending_req->result = SAM_STAT_GOOD; + scsiback_cmd_done(pending_req); + return 0; +} + +static int scsiback_queue_status(struct se_cmd *se_cmd) +{ + struct vscsibk_pend *pending_req = container_of(se_cmd, + struct vscsibk_pend, se_cmd); + + if (se_cmd->sense_buffer && + ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || + (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) + pending_req->result = (DRIVER_SENSE << 24) | + SAM_STAT_CHECK_CONDITION; + else + pending_req->result = se_cmd->scsi_status; + + scsiback_cmd_done(pending_req); + return 0; +} + +static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) +{ + struct vscsibk_pend *pending_req = container_of(se_cmd, + struct vscsibk_pend, se_cmd); + + complete(&pending_req->tmr_done); +} + +static void scsiback_aborted_task(struct se_cmd *se_cmd) +{ +} + +static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, + char *page) +{ + struct se_portal_group *se_tpg = param_to_tpg(item); + struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, + se_tpg); + ssize_t rb; + + mutex_lock(&tpg->tv_tpg_mutex); + rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); + mutex_unlock(&tpg->tv_tpg_mutex); + + return rb; +} + +static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, + const char *page, size_t count) +{ + struct se_portal_group *se_tpg = param_to_tpg(item); + struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, + se_tpg); + int len; + + if (strlen(page) >= VSCSI_NAMELEN) { + pr_err("param alias: %s, exceeds max: %d\n", page, + VSCSI_NAMELEN); + return -EINVAL; + } + + mutex_lock(&tpg->tv_tpg_mutex); + len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); + if (tpg->param_alias[len - 1] == '\n') + tpg->param_alias[len - 1] = '\0'; + mutex_unlock(&tpg->tv_tpg_mutex); + + return count; +} + +CONFIGFS_ATTR(scsiback_tpg_param_, alias); + +static struct configfs_attribute *scsiback_param_attrs[] = { + &scsiback_tpg_param_attr_alias, + NULL, +}; + +static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, + struct se_session *se_sess, void *p) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + + tpg->tpg_nexus = p; + return 0; +} + +static int scsiback_make_nexus(struct scsiback_tpg *tpg, + const char *name) +{ + struct scsiback_nexus *tv_nexus; + int ret = 0; + + mutex_lock(&tpg->tv_tpg_mutex); + if (tpg->tpg_nexus) { + pr_debug("tpg->tpg_nexus already exists\n"); + ret = -EEXIST; + goto out_unlock; + } + + tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); + if (!tv_nexus) { + ret = -ENOMEM; + goto out_unlock; + } + + tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, + VSCSI_DEFAULT_SESSION_TAGS, + sizeof(struct vscsibk_pend), + TARGET_PROT_NORMAL, name, + tv_nexus, scsiback_alloc_sess_cb); + if (IS_ERR(tv_nexus->tvn_se_sess)) { + kfree(tv_nexus); + ret = -ENOMEM; + goto out_unlock; + } + +out_unlock: + mutex_unlock(&tpg->tv_tpg_mutex); + return ret; +} + +static int scsiback_drop_nexus(struct scsiback_tpg *tpg) +{ + struct se_session *se_sess; + struct scsiback_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 (tpg->tv_tpg_port_count != 0) { + mutex_unlock(&tpg->tv_tpg_mutex); + pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", + tpg->tv_tpg_port_count); + return -EBUSY; + } + + if (tpg->tv_tpg_fe_count != 0) { + mutex_unlock(&tpg->tv_tpg_mutex); + pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", + tpg->tv_tpg_fe_count); + return -EBUSY; + } + + pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", + scsiback_dump_proto_id(tpg->tport), + tv_nexus->tvn_se_sess->se_node_acl->initiatorname); + + /* + * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port + */ + target_remove_session(se_sess); + tpg->tpg_nexus = NULL; + mutex_unlock(&tpg->tv_tpg_mutex); + + kfree(tv_nexus); + return 0; +} + +static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) +{ + struct se_portal_group *se_tpg = to_tpg(item); + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + struct scsiback_nexus *tv_nexus; + ssize_t ret; + + mutex_lock(&tpg->tv_tpg_mutex); + tv_nexus = tpg->tpg_nexus; + if (!tv_nexus) { + mutex_unlock(&tpg->tv_tpg_mutex); + return -ENODEV; + } + ret = snprintf(page, PAGE_SIZE, "%s\n", + tv_nexus->tvn_se_sess->se_node_acl->initiatorname); + mutex_unlock(&tpg->tv_tpg_mutex); + + return ret; +} + +static ssize_t scsiback_tpg_nexus_store(struct config_item *item, + const char *page, size_t count) +{ + struct se_portal_group *se_tpg = to_tpg(item); + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + struct scsiback_tport *tport_wwn = tpg->tport; + unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; + int ret; + /* + * Shutdown the active I_T nexus if 'NULL' is passed. + */ + if (!strncmp(page, "NULL", 4)) { + ret = scsiback_drop_nexus(tpg); + return (!ret) ? count : ret; + } + /* + * Otherwise make sure the passed virtual Initiator port WWN matches + * the fabric protocol_id set in scsiback_make_tport(), and call + * scsiback_make_nexus(). + */ + if (strlen(page) >= VSCSI_NAMELEN) { + pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", + page, VSCSI_NAMELEN); + return -EINVAL; + } + snprintf(&i_port[0], VSCSI_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, scsiback_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, scsiback_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, scsiback_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 = scsiback_make_nexus(tpg, port_ptr); + if (ret < 0) + return ret; + + return count; +} + +CONFIGFS_ATTR(scsiback_tpg_, nexus); + +static struct configfs_attribute *scsiback_tpg_attrs[] = { + &scsiback_tpg_attr_nexus, + NULL, +}; + +static ssize_t +scsiback_wwn_version_show(struct config_item *item, char *page) +{ + return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " + UTS_RELEASE"\n", + VSCSI_VERSION, utsname()->sysname, utsname()->machine); +} + +CONFIGFS_ATTR_RO(scsiback_wwn_, version); + +static struct configfs_attribute *scsiback_wwn_attrs[] = { + &scsiback_wwn_attr_version, + NULL, +}; + +static char *scsiback_get_fabric_name(void) +{ + return "xen-pvscsi"; +} + +static int scsiback_port_link(struct se_portal_group *se_tpg, + struct se_lun *lun) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + + mutex_lock(&tpg->tv_tpg_mutex); + tpg->tv_tpg_port_count++; + mutex_unlock(&tpg->tv_tpg_mutex); + + return 0; +} + +static void scsiback_port_unlink(struct se_portal_group *se_tpg, + struct se_lun *lun) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + + mutex_lock(&tpg->tv_tpg_mutex); + tpg->tv_tpg_port_count--; + mutex_unlock(&tpg->tv_tpg_mutex); +} + +static struct se_portal_group * +scsiback_make_tpg(struct se_wwn *wwn, const char *name) +{ + struct scsiback_tport *tport = container_of(wwn, + struct scsiback_tport, tport_wwn); + + struct scsiback_tpg *tpg; + u16 tpgt; + int ret; + + if (strstr(name, "tpgt_") != name) + return ERR_PTR(-EINVAL); + ret = kstrtou16(name + 5, 10, &tpgt); + if (ret) + return ERR_PTR(ret); + + tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); + if (!tpg) + return ERR_PTR(-ENOMEM); + + mutex_init(&tpg->tv_tpg_mutex); + INIT_LIST_HEAD(&tpg->tv_tpg_list); + INIT_LIST_HEAD(&tpg->info_list); + tpg->tport = tport; + tpg->tport_tpgt = tpgt; + + ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); + if (ret < 0) { + kfree(tpg); + return NULL; + } + mutex_lock(&scsiback_mutex); + list_add_tail(&tpg->tv_tpg_list, &scsiback_list); + mutex_unlock(&scsiback_mutex); + + return &tpg->se_tpg; +} + +static void scsiback_drop_tpg(struct se_portal_group *se_tpg) +{ + struct scsiback_tpg *tpg = container_of(se_tpg, + struct scsiback_tpg, se_tpg); + + mutex_lock(&scsiback_mutex); + list_del(&tpg->tv_tpg_list); + mutex_unlock(&scsiback_mutex); + /* + * Release the virtual I_T Nexus for this xen-pvscsi TPG + */ + scsiback_drop_nexus(tpg); + /* + * Deregister the se_tpg from TCM. + */ + core_tpg_deregister(se_tpg); + kfree(tpg); +} + +static int scsiback_check_true(struct se_portal_group *se_tpg) +{ + return 1; +} + +static int scsiback_check_false(struct se_portal_group *se_tpg) +{ + return 0; +} + +static const struct target_core_fabric_ops scsiback_ops = { + .module = THIS_MODULE, + .name = "xen-pvscsi", + .get_fabric_name = scsiback_get_fabric_name, + .tpg_get_wwn = scsiback_get_fabric_wwn, + .tpg_get_tag = scsiback_get_tag, + .tpg_check_demo_mode = scsiback_check_true, + .tpg_check_demo_mode_cache = scsiback_check_true, + .tpg_check_demo_mode_write_protect = scsiback_check_false, + .tpg_check_prod_mode_write_protect = scsiback_check_false, + .tpg_get_inst_index = scsiback_tpg_get_inst_index, + .check_stop_free = scsiback_check_stop_free, + .release_cmd = scsiback_release_cmd, + .sess_get_index = scsiback_sess_get_index, + .sess_get_initiator_sid = NULL, + .write_pending = scsiback_write_pending, + .write_pending_status = scsiback_write_pending_status, + .set_default_node_attributes = scsiback_set_default_node_attrs, + .get_cmd_state = scsiback_get_cmd_state, + .queue_data_in = scsiback_queue_data_in, + .queue_status = scsiback_queue_status, + .queue_tm_rsp = scsiback_queue_tm_rsp, + .aborted_task = scsiback_aborted_task, + /* + * Setup callers for generic logic in target_core_fabric_configfs.c + */ + .fabric_make_wwn = scsiback_make_tport, + .fabric_drop_wwn = scsiback_drop_tport, + .fabric_make_tpg = scsiback_make_tpg, + .fabric_drop_tpg = scsiback_drop_tpg, + .fabric_post_link = scsiback_port_link, + .fabric_pre_unlink = scsiback_port_unlink, + + .tfc_wwn_attrs = scsiback_wwn_attrs, + .tfc_tpg_base_attrs = scsiback_tpg_attrs, + .tfc_tpg_param_attrs = scsiback_param_attrs, +}; + +static const struct xenbus_device_id scsiback_ids[] = { + { "vscsi" }, + { "" } +}; + +static struct xenbus_driver scsiback_driver = { + .ids = scsiback_ids, + .probe = scsiback_probe, + .remove = scsiback_remove, + .otherend_changed = scsiback_frontend_changed +}; + +static int __init scsiback_init(void) +{ + int ret; + + if (!xen_domain()) + return -ENODEV; + + pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", + VSCSI_VERSION, utsname()->sysname, utsname()->machine); + + ret = xenbus_register_backend(&scsiback_driver); + if (ret) + goto out; + + ret = target_register_template(&scsiback_ops); + if (ret) + goto out_unregister_xenbus; + + return 0; + +out_unregister_xenbus: + xenbus_unregister_driver(&scsiback_driver); +out: + pr_err("%s: error %d\n", __func__, ret); + return ret; +} + +static void __exit scsiback_exit(void) +{ + struct page *page; + + while (free_pages_num) { + if (get_free_page(&page)) + BUG(); + gnttab_free_pages(1, &page); + } + target_unregister_template(&scsiback_ops); + xenbus_unregister_driver(&scsiback_driver); +} + +module_init(scsiback_init); +module_exit(scsiback_exit); + +MODULE_DESCRIPTION("Xen SCSI backend driver"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS("xen-backend:vscsi"); +MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); |