v4.19.13 snapshot.
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
new file mode 100644
index 0000000..14a3d4c
--- /dev/null
+++ b/drivers/xen/xen-scsiback.c
@@ -0,0 +1,1907 @@
+/*
+ * 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;
+ int ring_error;
+
+ 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);
+ BUG_ON(err);
+ 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;
+ 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)
+{
+ 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);
+ info->ring_error = 1;
+ return 0;
+ }
+
+ while ((rc != rp)) {
+ 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;
+
+ if (info->ring_error)
+ return IRQ_HANDLED;
+
+ while (scsiback_do_cmd_fn(info))
+ cond_resched();
+
+ 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(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);
+ info->ring_error = 0;
+ 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>");