1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2009, Microsoft Corporation.
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 * K. Y. Srinivasan <kys@microsoft.com>
11 #include <linux/kernel.h>
12 #include <linux/wait.h>
13 #include <linux/sched.h>
14 #include <linux/completion.h>
15 #include <linux/string.h>
17 #include <linux/delay.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/hyperv.h>
23 #include <linux/blkdev.h>
24 #include <linux/dma-mapping.h>
26 #include <scsi/scsi.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_devinfo.h>
33 #include <scsi/scsi_dbg.h>
34 #include <scsi/scsi_transport_fc.h>
35 #include <scsi/scsi_transport.h>
38 * All wire protocol details (storage protocol between the guest and the host)
39 * are consolidated here.
41 * Begin protocol definitions.
47 * V1 RC < 2008/1/31: 1.0
48 * V1 RC > 2008/1/31: 2.0
55 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_) ((((MAJOR_) & 0xff) << 8) | \
57 #define VMSTOR_PROTO_VERSION_WIN6 VMSTOR_PROTO_VERSION(2, 0)
58 #define VMSTOR_PROTO_VERSION_WIN7 VMSTOR_PROTO_VERSION(4, 2)
59 #define VMSTOR_PROTO_VERSION_WIN8 VMSTOR_PROTO_VERSION(5, 1)
60 #define VMSTOR_PROTO_VERSION_WIN8_1 VMSTOR_PROTO_VERSION(6, 0)
61 #define VMSTOR_PROTO_VERSION_WIN10 VMSTOR_PROTO_VERSION(6, 2)
63 /* channel callback timeout in ms */
64 #define CALLBACK_TIMEOUT 2
66 /* Packet structure describing virtual storage requests. */
67 enum vstor_packet_operation {
68 VSTOR_OPERATION_COMPLETE_IO = 1,
69 VSTOR_OPERATION_REMOVE_DEVICE = 2,
70 VSTOR_OPERATION_EXECUTE_SRB = 3,
71 VSTOR_OPERATION_RESET_LUN = 4,
72 VSTOR_OPERATION_RESET_ADAPTER = 5,
73 VSTOR_OPERATION_RESET_BUS = 6,
74 VSTOR_OPERATION_BEGIN_INITIALIZATION = 7,
75 VSTOR_OPERATION_END_INITIALIZATION = 8,
76 VSTOR_OPERATION_QUERY_PROTOCOL_VERSION = 9,
77 VSTOR_OPERATION_QUERY_PROPERTIES = 10,
78 VSTOR_OPERATION_ENUMERATE_BUS = 11,
79 VSTOR_OPERATION_FCHBA_DATA = 12,
80 VSTOR_OPERATION_CREATE_SUB_CHANNELS = 13,
81 VSTOR_OPERATION_MAXIMUM = 13
85 * WWN packet for Fibre Channel HBA
88 struct hv_fc_wwn_packet {
91 u8 primary_port_wwn[8];
92 u8 primary_node_wwn[8];
93 u8 secondary_port_wwn[8];
94 u8 secondary_node_wwn[8];
103 #define SRB_FLAGS_QUEUE_ACTION_ENABLE 0x00000002
104 #define SRB_FLAGS_DISABLE_DISCONNECT 0x00000004
105 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER 0x00000008
106 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE 0x00000010
107 #define SRB_FLAGS_DISABLE_AUTOSENSE 0x00000020
108 #define SRB_FLAGS_DATA_IN 0x00000040
109 #define SRB_FLAGS_DATA_OUT 0x00000080
110 #define SRB_FLAGS_NO_DATA_TRANSFER 0x00000000
111 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
112 #define SRB_FLAGS_NO_QUEUE_FREEZE 0x00000100
113 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE 0x00000200
114 #define SRB_FLAGS_FREE_SENSE_BUFFER 0x00000400
117 * This flag indicates the request is part of the workflow for processing a D3.
119 #define SRB_FLAGS_D3_PROCESSING 0x00000800
120 #define SRB_FLAGS_IS_ACTIVE 0x00010000
121 #define SRB_FLAGS_ALLOCATED_FROM_ZONE 0x00020000
122 #define SRB_FLAGS_SGLIST_FROM_POOL 0x00040000
123 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE 0x00080000
124 #define SRB_FLAGS_NO_KEEP_AWAKE 0x00100000
125 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE 0x00200000
126 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT 0x00400000
127 #define SRB_FLAGS_DONT_START_NEXT_PACKET 0x00800000
128 #define SRB_FLAGS_PORT_DRIVER_RESERVED 0x0F000000
129 #define SRB_FLAGS_CLASS_DRIVER_RESERVED 0xF0000000
131 #define SP_UNTAGGED ((unsigned char) ~0)
132 #define SRB_SIMPLE_TAG_REQUEST 0x20
135 * Platform neutral description of a scsi request -
136 * this remains the same across the write regardless of 32/64 bit
137 * note: it's patterned off the SCSI_PASS_THROUGH structure
139 #define STORVSC_MAX_CMD_LEN 0x10
141 /* Sense buffer size is the same for all versions since Windows 8 */
142 #define STORVSC_SENSE_BUFFER_SIZE 0x14
143 #define STORVSC_MAX_BUF_LEN_WITH_PADDING 0x14
146 * The storage protocol version is determined during the
147 * initial exchange with the host. It will indicate which
148 * storage functionality is available in the host.
150 static int vmstor_proto_version;
152 #define STORVSC_LOGGING_NONE 0
153 #define STORVSC_LOGGING_ERROR 1
154 #define STORVSC_LOGGING_WARN 2
156 static int logging_level = STORVSC_LOGGING_ERROR;
157 module_param(logging_level, int, S_IRUGO|S_IWUSR);
158 MODULE_PARM_DESC(logging_level,
159 "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
161 static inline bool do_logging(int level)
163 return logging_level >= level;
166 #define storvsc_log(dev, level, fmt, ...) \
168 if (do_logging(level)) \
169 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__); \
172 struct vmscsi_request {
183 u8 sense_info_length;
187 u32 data_transfer_length;
190 u8 cdb[STORVSC_MAX_CMD_LEN];
191 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
192 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
195 * The following was added in win8.
204 } __attribute((packed));
207 * The list of windows version in order of preference.
210 static const int protocol_version[] = {
211 VMSTOR_PROTO_VERSION_WIN10,
212 VMSTOR_PROTO_VERSION_WIN8_1,
213 VMSTOR_PROTO_VERSION_WIN8,
218 * This structure is sent during the initialization phase to get the different
219 * properties of the channel.
222 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL 0x1
224 struct vmstorage_channel_properties {
230 u32 max_transfer_bytes;
235 /* This structure is sent during the storage protocol negotiations. */
236 struct vmstorage_protocol_version {
237 /* Major (MSW) and minor (LSW) version numbers. */
241 * Revision number is auto-incremented whenever this file is changed
242 * (See FILL_VMSTOR_REVISION macro above). Mismatch does not
243 * definitely indicate incompatibility--but it does indicate mismatched
245 * This is only used on the windows side. Just set it to 0.
250 /* Channel Property Flags */
251 #define STORAGE_CHANNEL_REMOVABLE_FLAG 0x1
252 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG 0x2
254 struct vstor_packet {
255 /* Requested operation type */
256 enum vstor_packet_operation operation;
258 /* Flags - see below for values */
261 /* Status of the request returned from the server side. */
264 /* Data payload area */
267 * Structure used to forward SCSI commands from the
268 * client to the server.
270 struct vmscsi_request vm_srb;
272 /* Structure used to query channel properties. */
273 struct vmstorage_channel_properties storage_channel_properties;
275 /* Used during version negotiations. */
276 struct vmstorage_protocol_version version;
278 /* Fibre channel address packet */
279 struct hv_fc_wwn_packet wwn_packet;
281 /* Number of sub-channels to create */
282 u16 sub_channel_count;
284 /* This will be the maximum of the union members */
292 * This flag indicates that the server should send back a completion for this
296 #define REQUEST_COMPLETION_FLAG 0x1
298 /* Matches Windows-end */
299 enum storvsc_request_type {
306 * SRB status codes and masks; a subset of the codes used here.
309 #define SRB_STATUS_AUTOSENSE_VALID 0x80
310 #define SRB_STATUS_QUEUE_FROZEN 0x40
311 #define SRB_STATUS_INVALID_LUN 0x20
312 #define SRB_STATUS_SUCCESS 0x01
313 #define SRB_STATUS_ABORTED 0x02
314 #define SRB_STATUS_ERROR 0x04
315 #define SRB_STATUS_DATA_OVERRUN 0x12
317 #define SRB_STATUS(status) \
318 (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
320 * This is the end of Protocol specific defines.
323 static int storvsc_ringbuffer_size = (128 * 1024);
324 static u32 max_outstanding_req_per_channel;
325 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
327 static int storvsc_vcpus_per_sub_channel = 4;
328 static unsigned int storvsc_max_hw_queues;
330 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
331 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
333 module_param(storvsc_max_hw_queues, uint, 0644);
334 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
336 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
337 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
339 static int ring_avail_percent_lowater = 10;
340 module_param(ring_avail_percent_lowater, int, S_IRUGO);
341 MODULE_PARM_DESC(ring_avail_percent_lowater,
342 "Select a channel if available ring size > this in percent");
345 * Timeout in seconds for all devices managed by this driver.
347 static int storvsc_timeout = 180;
349 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
350 static struct scsi_transport_template *fc_transport_template;
353 static struct scsi_host_template scsi_driver;
354 static void storvsc_on_channel_callback(void *context);
356 #define STORVSC_MAX_LUNS_PER_TARGET 255
357 #define STORVSC_MAX_TARGETS 2
358 #define STORVSC_MAX_CHANNELS 8
360 #define STORVSC_FC_MAX_LUNS_PER_TARGET 255
361 #define STORVSC_FC_MAX_TARGETS 128
362 #define STORVSC_FC_MAX_CHANNELS 8
364 #define STORVSC_IDE_MAX_LUNS_PER_TARGET 64
365 #define STORVSC_IDE_MAX_TARGETS 1
366 #define STORVSC_IDE_MAX_CHANNELS 1
369 * Upper bound on the size of a storvsc packet.
371 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
372 sizeof(struct vstor_packet))
374 struct storvsc_cmd_request {
375 struct scsi_cmnd *cmd;
377 struct hv_device *device;
379 /* Synchronize the request/response if needed */
380 struct completion wait_event;
382 struct vmbus_channel_packet_multipage_buffer mpb;
383 struct vmbus_packet_mpb_array *payload;
386 struct vstor_packet vstor_packet;
390 /* A storvsc device is a device object that contains a vmbus channel */
391 struct storvsc_device {
392 struct hv_device *device;
396 atomic_t num_outstanding_req;
397 struct Scsi_Host *host;
399 wait_queue_head_t waiting_to_drain;
402 * Each unique Port/Path/Target represents 1 channel ie scsi
403 * controller. In reality, the pathid, targetid is always 0
404 * and the port is set by us
406 unsigned int port_number;
407 unsigned char path_id;
408 unsigned char target_id;
411 * Max I/O, the device can support.
413 u32 max_transfer_bytes;
415 * Number of sub-channels we will open.
418 struct vmbus_channel **stor_chns;
420 * Mask of CPUs bound to subchannels.
422 struct cpumask alloced_cpus;
424 * Serializes modifications of stor_chns[] from storvsc_do_io()
425 * and storvsc_change_target_cpu().
428 /* Used for vsc/vsp channel reset process */
429 struct storvsc_cmd_request init_request;
430 struct storvsc_cmd_request reset_request;
432 * Currently active port and node names for FC devices.
436 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
437 struct fc_rport *rport;
441 struct hv_host_device {
442 struct hv_device *dev;
445 unsigned char target;
446 struct workqueue_struct *handle_error_wq;
447 struct work_struct host_scan_work;
448 struct Scsi_Host *host;
451 struct storvsc_scan_work {
452 struct work_struct work;
453 struct Scsi_Host *host;
458 static void storvsc_device_scan(struct work_struct *work)
460 struct storvsc_scan_work *wrk;
461 struct scsi_device *sdev;
463 wrk = container_of(work, struct storvsc_scan_work, work);
465 sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
468 scsi_rescan_device(&sdev->sdev_gendev);
469 scsi_device_put(sdev);
475 static void storvsc_host_scan(struct work_struct *work)
477 struct Scsi_Host *host;
478 struct scsi_device *sdev;
479 struct hv_host_device *host_device =
480 container_of(work, struct hv_host_device, host_scan_work);
482 host = host_device->host;
484 * Before scanning the host, first check to see if any of the
485 * currently known devices have been hot removed. We issue a
486 * "unit ready" command against all currently known devices.
487 * This I/O will result in an error for devices that have been
488 * removed. As part of handling the I/O error, we remove the device.
490 * When a LUN is added or removed, the host sends us a signal to
491 * scan the host. Thus we are forced to discover the LUNs that
492 * may have been removed this way.
494 mutex_lock(&host->scan_mutex);
495 shost_for_each_device(sdev, host)
496 scsi_test_unit_ready(sdev, 1, 1, NULL);
497 mutex_unlock(&host->scan_mutex);
499 * Now scan the host to discover LUNs that may have been added.
501 scsi_scan_host(host);
504 static void storvsc_remove_lun(struct work_struct *work)
506 struct storvsc_scan_work *wrk;
507 struct scsi_device *sdev;
509 wrk = container_of(work, struct storvsc_scan_work, work);
510 if (!scsi_host_get(wrk->host))
513 sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
516 scsi_remove_device(sdev);
517 scsi_device_put(sdev);
519 scsi_host_put(wrk->host);
527 * We can get incoming messages from the host that are not in response to
528 * messages that we have sent out. An example of this would be messages
529 * received by the guest to notify dynamic addition/removal of LUNs. To
530 * deal with potential race conditions where the driver may be in the
531 * midst of being unloaded when we might receive an unsolicited message
532 * from the host, we have implemented a mechanism to gurantee sequential
535 * 1) Once the device is marked as being destroyed, we will fail all
537 * 2) We permit incoming messages when the device is being destroyed,
538 * only to properly account for messages already sent out.
541 static inline struct storvsc_device *get_out_stor_device(
542 struct hv_device *device)
544 struct storvsc_device *stor_device;
546 stor_device = hv_get_drvdata(device);
548 if (stor_device && stor_device->destroy)
555 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
557 dev->drain_notify = true;
558 wait_event(dev->waiting_to_drain,
559 atomic_read(&dev->num_outstanding_req) == 0);
560 dev->drain_notify = false;
563 static inline struct storvsc_device *get_in_stor_device(
564 struct hv_device *device)
566 struct storvsc_device *stor_device;
568 stor_device = hv_get_drvdata(device);
574 * If the device is being destroyed; allow incoming
575 * traffic only to cleanup outstanding requests.
578 if (stor_device->destroy &&
579 (atomic_read(&stor_device->num_outstanding_req) == 0))
587 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
590 struct storvsc_device *stor_device;
591 struct vmbus_channel *cur_chn;
592 bool old_is_alloced = false;
593 struct hv_device *device;
597 device = channel->primary_channel ?
598 channel->primary_channel->device_obj
599 : channel->device_obj;
600 stor_device = get_out_stor_device(device);
604 /* See storvsc_do_io() -> get_og_chn(). */
605 spin_lock_irqsave(&stor_device->lock, flags);
608 * Determines if the storvsc device has other channels assigned to
609 * the "old" CPU to update the alloced_cpus mask and the stor_chns
612 if (device->channel != channel && device->channel->target_cpu == old) {
613 cur_chn = device->channel;
614 old_is_alloced = true;
617 list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
618 if (cur_chn == channel)
620 if (cur_chn->target_cpu == old) {
621 old_is_alloced = true;
628 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
630 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
632 /* "Flush" the stor_chns array. */
633 for_each_possible_cpu(cpu) {
634 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
635 cpu, &stor_device->alloced_cpus))
636 WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
639 WRITE_ONCE(stor_device->stor_chns[new], channel);
640 cpumask_set_cpu(new, &stor_device->alloced_cpus);
642 spin_unlock_irqrestore(&stor_device->lock, flags);
645 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
647 struct storvsc_cmd_request *request =
648 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
650 if (rqst_addr == VMBUS_RQST_INIT)
651 return VMBUS_RQST_INIT;
652 if (rqst_addr == VMBUS_RQST_RESET)
653 return VMBUS_RQST_RESET;
656 * Cannot return an ID of 0, which is reserved for an unsolicited
657 * message from Hyper-V.
659 return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
662 static void handle_sc_creation(struct vmbus_channel *new_sc)
664 struct hv_device *device = new_sc->primary_channel->device_obj;
665 struct device *dev = &device->device;
666 struct storvsc_device *stor_device;
667 struct vmstorage_channel_properties props;
670 stor_device = get_out_stor_device(device);
674 memset(&props, 0, sizeof(struct vmstorage_channel_properties));
675 new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
677 new_sc->next_request_id_callback = storvsc_next_request_id;
679 ret = vmbus_open(new_sc,
680 storvsc_ringbuffer_size,
681 storvsc_ringbuffer_size,
683 sizeof(struct vmstorage_channel_properties),
684 storvsc_on_channel_callback, new_sc);
686 /* In case vmbus_open() fails, we don't use the sub-channel. */
688 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
692 new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
694 /* Add the sub-channel to the array of available channels. */
695 stor_device->stor_chns[new_sc->target_cpu] = new_sc;
696 cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
699 static void handle_multichannel_storage(struct hv_device *device, int max_chns)
701 struct device *dev = &device->device;
702 struct storvsc_device *stor_device;
704 struct storvsc_cmd_request *request;
705 struct vstor_packet *vstor_packet;
709 * If the number of CPUs is artificially restricted, such as
710 * with maxcpus=1 on the kernel boot line, Hyper-V could offer
711 * sub-channels >= the number of CPUs. These sub-channels
712 * should not be created. The primary channel is already created
713 * and assigned to one CPU, so check against # CPUs - 1.
715 num_sc = min((int)(num_online_cpus() - 1), max_chns);
719 stor_device = get_out_stor_device(device);
723 stor_device->num_sc = num_sc;
724 request = &stor_device->init_request;
725 vstor_packet = &request->vstor_packet;
728 * Establish a handler for dealing with subchannels.
730 vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
733 * Request the host to create sub-channels.
735 memset(request, 0, sizeof(struct storvsc_cmd_request));
736 init_completion(&request->wait_event);
737 vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
738 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
739 vstor_packet->sub_channel_count = num_sc;
741 ret = vmbus_sendpacket(device->channel, vstor_packet,
742 sizeof(struct vstor_packet),
745 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
748 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
752 t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
754 dev_err(dev, "Failed to create sub-channel: timed out\n");
758 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
759 vstor_packet->status != 0) {
760 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
761 vstor_packet->operation, vstor_packet->status);
766 * We need to do nothing here, because vmbus_process_offer()
767 * invokes channel->sc_creation_callback, which will open and use
768 * the sub-channel(s).
772 static void cache_wwn(struct storvsc_device *stor_device,
773 struct vstor_packet *vstor_packet)
776 * Cache the currently active port and node ww names.
778 if (vstor_packet->wwn_packet.primary_active) {
779 stor_device->node_name =
780 wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
781 stor_device->port_name =
782 wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
784 stor_device->node_name =
785 wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
786 stor_device->port_name =
787 wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
792 static int storvsc_execute_vstor_op(struct hv_device *device,
793 struct storvsc_cmd_request *request,
796 struct storvsc_device *stor_device;
797 struct vstor_packet *vstor_packet;
800 stor_device = get_out_stor_device(device);
804 vstor_packet = &request->vstor_packet;
806 init_completion(&request->wait_event);
807 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
809 ret = vmbus_sendpacket(device->channel, vstor_packet,
810 sizeof(struct vstor_packet),
813 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
817 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
824 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
825 vstor_packet->status != 0)
831 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
833 struct storvsc_device *stor_device;
834 struct storvsc_cmd_request *request;
835 struct vstor_packet *vstor_packet;
838 bool process_sub_channels = false;
840 stor_device = get_out_stor_device(device);
844 request = &stor_device->init_request;
845 vstor_packet = &request->vstor_packet;
848 * Now, initiate the vsc/vsp initialization protocol on the open
851 memset(request, 0, sizeof(struct storvsc_cmd_request));
852 vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
853 ret = storvsc_execute_vstor_op(device, request, true);
857 * Query host supported protocol version.
860 for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
861 /* reuse the packet for version range supported */
862 memset(vstor_packet, 0, sizeof(struct vstor_packet));
863 vstor_packet->operation =
864 VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
866 vstor_packet->version.major_minor = protocol_version[i];
869 * The revision number is only used in Windows; set it to 0.
871 vstor_packet->version.revision = 0;
872 ret = storvsc_execute_vstor_op(device, request, false);
876 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
879 if (vstor_packet->status == 0) {
880 vmstor_proto_version = protocol_version[i];
886 if (vstor_packet->status != 0) {
887 dev_err(&device->device, "Obsolete Hyper-V version\n");
892 memset(vstor_packet, 0, sizeof(struct vstor_packet));
893 vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
894 ret = storvsc_execute_vstor_op(device, request, true);
899 * Check to see if multi-channel support is there.
900 * Hosts that implement protocol version of 5.1 and above
901 * support multi-channel.
903 max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
906 * Allocate state to manage the sub-channels.
907 * We allocate an array based on the numbers of possible CPUs
908 * (Hyper-V does not support cpu online/offline).
909 * This Array will be sparseley populated with unique
910 * channels - primary + sub-channels.
911 * We will however populate all the slots to evenly distribute
914 stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
916 if (stor_device->stor_chns == NULL)
919 device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
921 stor_device->stor_chns[device->channel->target_cpu] = device->channel;
922 cpumask_set_cpu(device->channel->target_cpu,
923 &stor_device->alloced_cpus);
925 if (vstor_packet->storage_channel_properties.flags &
926 STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
927 process_sub_channels = true;
929 stor_device->max_transfer_bytes =
930 vstor_packet->storage_channel_properties.max_transfer_bytes;
936 * For FC devices retrieve FC HBA data.
938 memset(vstor_packet, 0, sizeof(struct vstor_packet));
939 vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
940 ret = storvsc_execute_vstor_op(device, request, true);
945 * Cache the currently active port and node ww names.
947 cache_wwn(stor_device, vstor_packet);
951 memset(vstor_packet, 0, sizeof(struct vstor_packet));
952 vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
953 ret = storvsc_execute_vstor_op(device, request, true);
957 if (process_sub_channels)
958 handle_multichannel_storage(device, max_chns);
963 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
964 struct scsi_cmnd *scmnd,
965 struct Scsi_Host *host,
968 struct storvsc_scan_work *wrk;
969 void (*process_err_fn)(struct work_struct *work);
970 struct hv_host_device *host_dev = shost_priv(host);
973 * In some situations, Hyper-V sets multiple bits in the
974 * srb_status, such as ABORTED and ERROR. So process them
975 * individually, with the most specific bits first.
978 if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
979 set_host_byte(scmnd, DID_NO_CONNECT);
980 process_err_fn = storvsc_remove_lun;
984 if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
985 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
986 /* Capacity data has changed */
987 (asc == 0x2a) && (ascq == 0x9)) {
988 process_err_fn = storvsc_device_scan;
990 * Retry the I/O that triggered this.
992 set_host_byte(scmnd, DID_REQUEUE);
997 if (vm_srb->srb_status & SRB_STATUS_ERROR) {
999 * Let upper layer deal with error when
1000 * sense message is present.
1002 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1006 * If there is an error; offline the device since all
1007 * error recovery strategies would have already been
1008 * deployed on the host side. However, if the command
1009 * were a pass-through command deal with it appropriately.
1011 switch (scmnd->cmnd[0]) {
1014 set_host_byte(scmnd, DID_PASSTHROUGH);
1017 * On some Hyper-V hosts TEST_UNIT_READY command can
1018 * return SRB_STATUS_ERROR. Let the upper level code
1019 * deal with it based on the sense information.
1021 case TEST_UNIT_READY:
1024 set_host_byte(scmnd, DID_ERROR);
1031 * We need to schedule work to process this error; schedule it.
1033 wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1035 set_host_byte(scmnd, DID_BAD_TARGET);
1040 wrk->lun = vm_srb->lun;
1041 wrk->tgt_id = vm_srb->target_id;
1042 INIT_WORK(&wrk->work, process_err_fn);
1043 queue_work(host_dev->handle_error_wq, &wrk->work);
1047 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1048 struct storvsc_device *stor_dev)
1050 struct scsi_cmnd *scmnd = cmd_request->cmd;
1051 struct scsi_sense_hdr sense_hdr;
1052 struct vmscsi_request *vm_srb;
1053 u32 data_transfer_length;
1054 struct Scsi_Host *host;
1055 u32 payload_sz = cmd_request->payload_sz;
1056 void *payload = cmd_request->payload;
1059 host = stor_dev->host;
1061 vm_srb = &cmd_request->vstor_packet.vm_srb;
1062 data_transfer_length = vm_srb->data_transfer_length;
1064 scmnd->result = vm_srb->scsi_status;
1066 if (scmnd->result) {
1067 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1068 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1070 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1071 scsi_print_sense_hdr(scmnd->device, "storvsc",
1075 if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1076 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1079 * The Windows driver set data_transfer_length on
1080 * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1081 * is untouched. In these cases we set it to 0.
1083 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1084 data_transfer_length = 0;
1087 /* Validate data_transfer_length (from Hyper-V) */
1088 if (data_transfer_length > cmd_request->payload->range.len)
1089 data_transfer_length = cmd_request->payload->range.len;
1091 scsi_set_resid(scmnd,
1092 cmd_request->payload->range.len - data_transfer_length);
1097 sizeof(struct vmbus_channel_packet_multipage_buffer))
1101 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1102 struct vstor_packet *vstor_packet,
1103 struct storvsc_cmd_request *request)
1105 struct vstor_packet *stor_pkt;
1106 struct hv_device *device = stor_device->device;
1108 stor_pkt = &request->vstor_packet;
1111 * The current SCSI handling on the host side does
1112 * not correctly handle:
1113 * INQUIRY command with page code parameter set to 0x80
1114 * MODE_SENSE command with cmd[2] == 0x1c
1116 * Setup srb and scsi status so this won't be fatal.
1117 * We do this so we can distinguish truly fatal failues
1118 * (srb status == 0x4) and off-line the device in that case.
1121 if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1122 (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1123 vstor_packet->vm_srb.scsi_status = 0;
1124 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1127 /* Copy over the status...etc */
1128 stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1129 stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1132 * Copy over the sense_info_length, but limit to the known max
1133 * size if Hyper-V returns a bad value.
1135 stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1136 vstor_packet->vm_srb.sense_info_length);
1138 if (vstor_packet->vm_srb.scsi_status != 0 ||
1139 vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1142 * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1143 * return errors when detecting devices using TEST_UNIT_READY,
1144 * and logging these as errors produces unhelpful noise.
1146 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1147 STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1149 storvsc_log(device, loglevel,
1150 "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1151 scsi_cmd_to_rq(request->cmd)->tag,
1152 stor_pkt->vm_srb.cdb[0],
1153 vstor_packet->vm_srb.scsi_status,
1154 vstor_packet->vm_srb.srb_status,
1155 vstor_packet->status);
1158 if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1159 (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1160 memcpy(request->cmd->sense_buffer,
1161 vstor_packet->vm_srb.sense_data,
1162 stor_pkt->vm_srb.sense_info_length);
1164 stor_pkt->vm_srb.data_transfer_length =
1165 vstor_packet->vm_srb.data_transfer_length;
1167 storvsc_command_completion(request, stor_device);
1169 if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1170 stor_device->drain_notify)
1171 wake_up(&stor_device->waiting_to_drain);
1174 static void storvsc_on_receive(struct storvsc_device *stor_device,
1175 struct vstor_packet *vstor_packet,
1176 struct storvsc_cmd_request *request)
1178 struct hv_host_device *host_dev;
1179 switch (vstor_packet->operation) {
1180 case VSTOR_OPERATION_COMPLETE_IO:
1181 storvsc_on_io_completion(stor_device, vstor_packet, request);
1184 case VSTOR_OPERATION_REMOVE_DEVICE:
1185 case VSTOR_OPERATION_ENUMERATE_BUS:
1186 host_dev = shost_priv(stor_device->host);
1188 host_dev->handle_error_wq, &host_dev->host_scan_work);
1191 case VSTOR_OPERATION_FCHBA_DATA:
1192 cache_wwn(stor_device, vstor_packet);
1193 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1194 fc_host_node_name(stor_device->host) = stor_device->node_name;
1195 fc_host_port_name(stor_device->host) = stor_device->port_name;
1203 static void storvsc_on_channel_callback(void *context)
1205 struct vmbus_channel *channel = (struct vmbus_channel *)context;
1206 const struct vmpacket_descriptor *desc;
1207 struct hv_device *device;
1208 struct storvsc_device *stor_device;
1209 struct Scsi_Host *shost;
1210 unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1212 if (channel->primary_channel != NULL)
1213 device = channel->primary_channel->device_obj;
1215 device = channel->device_obj;
1217 stor_device = get_in_stor_device(device);
1221 shost = stor_device->host;
1223 foreach_vmbus_pkt(desc, channel) {
1224 struct vstor_packet *packet = hv_pkt_data(desc);
1225 struct storvsc_cmd_request *request = NULL;
1226 u32 pktlen = hv_pkt_datalen(desc);
1227 u64 rqst_id = desc->trans_id;
1228 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1229 sizeof(enum vstor_packet_operation);
1231 if (unlikely(time_after(jiffies, time_limit))) {
1232 hv_pkt_iter_close(channel);
1236 if (pktlen < minlen) {
1237 dev_err(&device->device,
1238 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1239 rqst_id, pktlen, minlen);
1243 if (rqst_id == VMBUS_RQST_INIT) {
1244 request = &stor_device->init_request;
1245 } else if (rqst_id == VMBUS_RQST_RESET) {
1246 request = &stor_device->reset_request;
1248 /* Hyper-V can send an unsolicited message with ID of 0 */
1251 * storvsc_on_receive() looks at the vstor_packet in the message
1252 * from the ring buffer.
1254 * - If the operation in the vstor_packet is COMPLETE_IO, then
1255 * we call storvsc_on_io_completion(), and dereference the
1256 * guest memory address. Make sure we don't call
1257 * storvsc_on_io_completion() with a guest memory address
1258 * that is zero if Hyper-V were to construct and send such
1261 * - If the operation in the vstor_packet is FCHBA_DATA, then
1262 * we call cache_wwn(), and access the data payload area of
1263 * the packet (wwn_packet); however, there is no guarantee
1264 * that the packet is big enough to contain such area.
1265 * Future-proof the code by rejecting such a bogus packet.
1267 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1268 packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1269 dev_err(&device->device, "Invalid packet with ID of 0\n");
1273 struct scsi_cmnd *scmnd;
1275 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1276 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1277 if (scmnd == NULL) {
1278 dev_err(&device->device, "Incorrect transaction ID\n");
1281 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1282 scsi_dma_unmap(scmnd);
1285 storvsc_on_receive(stor_device, packet, request);
1289 memcpy(&request->vstor_packet, packet,
1290 sizeof(struct vstor_packet));
1291 complete(&request->wait_event);
1295 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1298 struct vmstorage_channel_properties props;
1301 memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1303 device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1304 device->channel->next_request_id_callback = storvsc_next_request_id;
1306 ret = vmbus_open(device->channel,
1310 sizeof(struct vmstorage_channel_properties),
1311 storvsc_on_channel_callback, device->channel);
1316 ret = storvsc_channel_init(device, is_fc);
1321 static int storvsc_dev_remove(struct hv_device *device)
1323 struct storvsc_device *stor_device;
1325 stor_device = hv_get_drvdata(device);
1327 stor_device->destroy = true;
1329 /* Make sure flag is set before waiting */
1333 * At this point, all outbound traffic should be disable. We
1334 * only allow inbound traffic (responses) to proceed so that
1335 * outstanding requests can be completed.
1338 storvsc_wait_to_drain(stor_device);
1341 * Since we have already drained, we don't need to busy wait
1342 * as was done in final_release_stor_device()
1343 * Note that we cannot set the ext pointer to NULL until
1344 * we have drained - to drain the outgoing packets, we need to
1345 * allow incoming packets.
1347 hv_set_drvdata(device, NULL);
1349 /* Close the channel */
1350 vmbus_close(device->channel);
1352 kfree(stor_device->stor_chns);
1357 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1362 const struct cpumask *node_mask;
1363 int num_channels, tgt_cpu;
1365 if (stor_device->num_sc == 0) {
1366 stor_device->stor_chns[q_num] = stor_device->device->channel;
1367 return stor_device->device->channel;
1371 * Our channel array is sparsley populated and we
1372 * initiated I/O on a processor/hw-q that does not
1373 * currently have a designated channel. Fix this.
1374 * The strategy is simple:
1375 * I. Ensure NUMA locality
1376 * II. Distribute evenly (best effort)
1379 node_mask = cpumask_of_node(cpu_to_node(q_num));
1382 for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1383 if (cpumask_test_cpu(tgt_cpu, node_mask))
1386 if (num_channels == 0) {
1387 stor_device->stor_chns[q_num] = stor_device->device->channel;
1388 return stor_device->device->channel;
1392 while (hash_qnum >= num_channels)
1393 hash_qnum -= num_channels;
1395 for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1396 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1398 if (slot == hash_qnum)
1403 stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1405 return stor_device->stor_chns[q_num];
1409 static int storvsc_do_io(struct hv_device *device,
1410 struct storvsc_cmd_request *request, u16 q_num)
1412 struct storvsc_device *stor_device;
1413 struct vstor_packet *vstor_packet;
1414 struct vmbus_channel *outgoing_channel, *channel;
1415 unsigned long flags;
1417 const struct cpumask *node_mask;
1420 vstor_packet = &request->vstor_packet;
1421 stor_device = get_out_stor_device(device);
1427 request->device = device;
1429 * Select an appropriate channel to send the request out.
1431 /* See storvsc_change_target_cpu(). */
1432 outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1433 if (outgoing_channel != NULL) {
1434 if (outgoing_channel->target_cpu == q_num) {
1436 * Ideally, we want to pick a different channel if
1437 * available on the same NUMA node.
1439 node_mask = cpumask_of_node(cpu_to_node(q_num));
1440 for_each_cpu_wrap(tgt_cpu,
1441 &stor_device->alloced_cpus, q_num + 1) {
1442 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1444 if (tgt_cpu == q_num)
1446 channel = READ_ONCE(
1447 stor_device->stor_chns[tgt_cpu]);
1448 if (channel == NULL)
1450 if (hv_get_avail_to_write_percent(
1452 > ring_avail_percent_lowater) {
1453 outgoing_channel = channel;
1459 * All the other channels on the same NUMA node are
1460 * busy. Try to use the channel on the current CPU
1462 if (hv_get_avail_to_write_percent(
1463 &outgoing_channel->outbound)
1464 > ring_avail_percent_lowater)
1468 * If we reach here, all the channels on the current
1469 * NUMA node are busy. Try to find a channel in
1472 for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1473 if (cpumask_test_cpu(tgt_cpu, node_mask))
1475 channel = READ_ONCE(
1476 stor_device->stor_chns[tgt_cpu]);
1477 if (channel == NULL)
1479 if (hv_get_avail_to_write_percent(
1481 > ring_avail_percent_lowater) {
1482 outgoing_channel = channel;
1488 spin_lock_irqsave(&stor_device->lock, flags);
1489 outgoing_channel = stor_device->stor_chns[q_num];
1490 if (outgoing_channel != NULL) {
1491 spin_unlock_irqrestore(&stor_device->lock, flags);
1494 outgoing_channel = get_og_chn(stor_device, q_num);
1495 spin_unlock_irqrestore(&stor_device->lock, flags);
1499 vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1501 vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1504 vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1507 vstor_packet->vm_srb.data_transfer_length =
1508 request->payload->range.len;
1510 vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1512 if (request->payload->range.len) {
1514 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1515 request->payload, request->payload_sz,
1517 sizeof(struct vstor_packet),
1518 (unsigned long)request);
1520 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1521 sizeof(struct vstor_packet),
1522 (unsigned long)request,
1524 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1530 atomic_inc(&stor_device->num_outstanding_req);
1535 static int storvsc_device_alloc(struct scsi_device *sdevice)
1538 * Set blist flag to permit the reading of the VPD pages even when
1539 * the target may claim SPC-2 compliance. MSFT targets currently
1540 * claim SPC-2 compliance while they implement post SPC-2 features.
1541 * With this flag we can correctly handle WRITE_SAME_16 issues.
1543 * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1544 * still supports REPORT LUN.
1546 sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1551 static int storvsc_device_configure(struct scsi_device *sdevice)
1553 blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1555 sdevice->no_write_same = 1;
1558 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1559 * if the device is a MSFT virtual device. If the host is
1560 * WIN10 or newer, allow write_same.
1562 if (!strncmp(sdevice->vendor, "Msft", 4)) {
1563 switch (vmstor_proto_version) {
1564 case VMSTOR_PROTO_VERSION_WIN8:
1565 case VMSTOR_PROTO_VERSION_WIN8_1:
1566 sdevice->scsi_level = SCSI_SPC_3;
1570 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1571 sdevice->no_write_same = 0;
1577 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1578 sector_t capacity, int *info)
1580 sector_t nsect = capacity;
1581 sector_t cylinders = nsect;
1582 int heads, sectors_pt;
1585 * We are making up these values; let us keep it simple.
1588 sectors_pt = 0x3f; /* Sectors per track */
1589 sector_div(cylinders, heads * sectors_pt);
1590 if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1594 info[1] = sectors_pt;
1595 info[2] = (int)cylinders;
1600 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1602 struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1603 struct hv_device *device = host_dev->dev;
1605 struct storvsc_device *stor_device;
1606 struct storvsc_cmd_request *request;
1607 struct vstor_packet *vstor_packet;
1610 stor_device = get_out_stor_device(device);
1614 request = &stor_device->reset_request;
1615 vstor_packet = &request->vstor_packet;
1616 memset(vstor_packet, 0, sizeof(struct vstor_packet));
1618 init_completion(&request->wait_event);
1620 vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1621 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1622 vstor_packet->vm_srb.path_id = stor_device->path_id;
1624 ret = vmbus_sendpacket(device->channel, vstor_packet,
1625 sizeof(struct vstor_packet),
1628 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1632 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1634 return TIMEOUT_ERROR;
1638 * At this point, all outstanding requests in the adapter
1639 * should have been flushed out and return to us
1640 * There is a potential race here where the host may be in
1641 * the process of responding when we return from here.
1642 * Just wait for all in-transit packets to be accounted for
1643 * before we return from here.
1645 storvsc_wait_to_drain(stor_device);
1651 * The host guarantees to respond to each command, although I/O latencies might
1652 * be unbounded on Azure. Reset the timer unconditionally to give the host a
1653 * chance to perform EH.
1655 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1657 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1658 if (scmnd->device->host->transportt == fc_transport_template)
1659 return fc_eh_timed_out(scmnd);
1661 return BLK_EH_RESET_TIMER;
1664 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1666 bool allowed = true;
1667 u8 scsi_op = scmnd->cmnd[0];
1670 /* the host does not handle WRITE_SAME, log accident usage */
1673 * smartd sends this command and the host does not handle
1674 * this. So, don't send it.
1677 set_host_byte(scmnd, DID_ERROR);
1686 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1689 struct hv_host_device *host_dev = shost_priv(host);
1690 struct hv_device *dev = host_dev->dev;
1691 struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1692 struct scatterlist *sgl;
1693 struct vmscsi_request *vm_srb;
1694 struct vmbus_packet_mpb_array *payload;
1698 if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1700 * On legacy hosts filter unimplemented commands.
1701 * Future hosts are expected to correctly handle
1702 * unsupported commands. Furthermore, it is
1703 * possible that some of the currently
1704 * unsupported commands maybe supported in
1705 * future versions of the host.
1707 if (!storvsc_scsi_cmd_ok(scmnd)) {
1713 /* Setup the cmd request */
1714 cmd_request->cmd = scmnd;
1716 memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1717 vm_srb = &cmd_request->vstor_packet.vm_srb;
1718 vm_srb->time_out_value = 60;
1720 vm_srb->srb_flags |=
1721 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1723 if (scmnd->device->tagged_supported) {
1724 vm_srb->srb_flags |=
1725 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1726 vm_srb->queue_tag = SP_UNTAGGED;
1727 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1731 switch (scmnd->sc_data_direction) {
1733 vm_srb->data_in = WRITE_TYPE;
1734 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1736 case DMA_FROM_DEVICE:
1737 vm_srb->data_in = READ_TYPE;
1738 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1741 vm_srb->data_in = UNKNOWN_TYPE;
1742 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1746 * This is DMA_BIDIRECTIONAL or something else we are never
1747 * supposed to see here.
1749 WARN(1, "Unexpected data direction: %d\n",
1750 scmnd->sc_data_direction);
1755 vm_srb->port_number = host_dev->port;
1756 vm_srb->path_id = scmnd->device->channel;
1757 vm_srb->target_id = scmnd->device->id;
1758 vm_srb->lun = scmnd->device->lun;
1760 vm_srb->cdb_length = scmnd->cmd_len;
1762 memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1764 sgl = (struct scatterlist *)scsi_sglist(scmnd);
1766 length = scsi_bufflen(scmnd);
1767 payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1768 payload_sz = sizeof(cmd_request->mpb);
1770 if (scsi_sg_count(scmnd)) {
1771 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1772 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1773 struct scatterlist *sg;
1774 unsigned long hvpfn, hvpfns_to_add;
1775 int j, i = 0, sg_count;
1777 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1779 payload_sz = (hvpg_count * sizeof(u64) +
1780 sizeof(struct vmbus_packet_mpb_array));
1781 payload = kzalloc(payload_sz, GFP_ATOMIC);
1783 return SCSI_MLQUEUE_DEVICE_BUSY;
1786 payload->range.len = length;
1787 payload->range.offset = offset_in_hvpg;
1789 sg_count = scsi_dma_map(scmnd);
1791 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1792 goto err_free_payload;
1795 for_each_sg(sgl, sg, sg_count, j) {
1797 * Init values for the current sgl entry. hvpfns_to_add
1798 * is in units of Hyper-V size pages. Handling the
1799 * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1800 * values of sgl->offset that are larger than PAGE_SIZE.
1801 * Such offsets are handled even on other than the first
1802 * sgl entry, provided they are a multiple of PAGE_SIZE.
1804 hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1805 hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1806 sg_dma_len(sg)) - hvpfn;
1809 * Fill the next portion of the PFN array with
1810 * sequential Hyper-V PFNs for the continguous physical
1811 * memory described by the sgl entry. The end of the
1812 * last sgl should be reached at the same time that
1813 * the PFN array is filled.
1815 while (hvpfns_to_add--)
1816 payload->range.pfn_array[i++] = hvpfn++;
1820 cmd_request->payload = payload;
1821 cmd_request->payload_sz = payload_sz;
1823 /* Invokes the vsc to start an IO */
1824 ret = storvsc_do_io(dev, cmd_request, get_cpu());
1827 if (ret == -EAGAIN) {
1829 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1830 goto err_free_payload;
1836 if (payload_sz > sizeof(cmd_request->mpb))
1842 static struct scsi_host_template scsi_driver = {
1843 .module = THIS_MODULE,
1844 .name = "storvsc_host_t",
1845 .cmd_size = sizeof(struct storvsc_cmd_request),
1846 .bios_param = storvsc_get_chs,
1847 .queuecommand = storvsc_queuecommand,
1848 .eh_host_reset_handler = storvsc_host_reset_handler,
1849 .proc_name = "storvsc_host",
1850 .eh_timed_out = storvsc_eh_timed_out,
1851 .slave_alloc = storvsc_device_alloc,
1852 .slave_configure = storvsc_device_configure,
1853 .cmd_per_lun = 2048,
1855 /* Ensure there are no gaps in presented sgls */
1856 .virt_boundary_mask = HV_HYP_PAGE_SIZE - 1,
1858 .track_queue_depth = 1,
1859 .change_queue_depth = storvsc_change_queue_depth,
1868 static const struct hv_vmbus_device_id id_table[] = {
1871 .driver_data = SCSI_GUID
1875 .driver_data = IDE_GUID
1877 /* Fibre Channel GUID */
1880 .driver_data = SFC_GUID
1885 MODULE_DEVICE_TABLE(vmbus, id_table);
1887 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1889 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1891 return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1894 static int storvsc_probe(struct hv_device *device,
1895 const struct hv_vmbus_device_id *dev_id)
1898 int num_cpus = num_online_cpus();
1899 int num_present_cpus = num_present_cpus();
1900 struct Scsi_Host *host;
1901 struct hv_host_device *host_dev;
1902 bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1903 bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1905 struct storvsc_device *stor_device;
1906 int max_sub_channels = 0;
1910 * We support sub-channels for storage on SCSI and FC controllers.
1911 * The number of sub-channels offerred is based on the number of
1912 * VCPUs in the guest.
1916 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1918 scsi_driver.can_queue = max_outstanding_req_per_channel *
1919 (max_sub_channels + 1) *
1920 (100 - ring_avail_percent_lowater) / 100;
1922 host = scsi_host_alloc(&scsi_driver,
1923 sizeof(struct hv_host_device));
1927 host_dev = shost_priv(host);
1928 memset(host_dev, 0, sizeof(struct hv_host_device));
1930 host_dev->port = host->host_no;
1931 host_dev->dev = device;
1932 host_dev->host = host;
1935 stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1941 stor_device->destroy = false;
1942 init_waitqueue_head(&stor_device->waiting_to_drain);
1943 stor_device->device = device;
1944 stor_device->host = host;
1945 spin_lock_init(&stor_device->lock);
1946 hv_set_drvdata(device, stor_device);
1947 dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1949 stor_device->port_number = host->host_no;
1950 ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1954 host_dev->path = stor_device->path_id;
1955 host_dev->target = stor_device->target_id;
1957 switch (dev_id->driver_data) {
1959 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1960 host->max_id = STORVSC_FC_MAX_TARGETS;
1961 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1962 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1963 host->transportt = fc_transport_template;
1968 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1969 host->max_id = STORVSC_MAX_TARGETS;
1970 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1974 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1975 host->max_id = STORVSC_IDE_MAX_TARGETS;
1976 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1979 /* max cmd length */
1980 host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1982 * Any reasonable Hyper-V configuration should provide
1983 * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
1984 * protecting it from any weird value.
1986 max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
1987 /* max_hw_sectors_kb */
1988 host->max_sectors = max_xfer_bytes >> 9;
1990 * There are 2 requirements for Hyper-V storvsc sgl segments,
1991 * based on which the below calculation for max segments is
1994 * 1. Except for the first and last sgl segment, all sgl segments
1995 * should be align to HV_HYP_PAGE_SIZE, that also means the
1996 * maximum number of segments in a sgl can be calculated by
1997 * dividing the total max transfer length by HV_HYP_PAGE_SIZE.
1999 * 2. Except for the first and last, each entry in the SGL must
2000 * have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2002 host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2004 * For non-IDE disks, the host supports multiple channels.
2005 * Set the number of HW queues we are supporting.
2008 if (storvsc_max_hw_queues > num_present_cpus) {
2009 storvsc_max_hw_queues = 0;
2010 storvsc_log(device, STORVSC_LOGGING_WARN,
2011 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2013 if (storvsc_max_hw_queues)
2014 host->nr_hw_queues = storvsc_max_hw_queues;
2016 host->nr_hw_queues = num_present_cpus;
2020 * Set the error handler work queue.
2022 host_dev->handle_error_wq =
2023 alloc_ordered_workqueue("storvsc_error_wq_%d",
2026 if (!host_dev->handle_error_wq) {
2030 INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2031 /* Register the HBA and start the scsi bus scan */
2032 ret = scsi_add_host(host, &device->device);
2037 scsi_scan_host(host);
2039 target = (device->dev_instance.b[5] << 8 |
2040 device->dev_instance.b[4]);
2041 ret = scsi_add_device(host, 0, target, 0);
2045 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2046 if (host->transportt == fc_transport_template) {
2047 struct fc_rport_identifiers ids = {
2048 .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2051 fc_host_node_name(host) = stor_device->node_name;
2052 fc_host_port_name(host) = stor_device->port_name;
2053 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2054 if (!stor_device->rport) {
2063 scsi_remove_host(host);
2066 destroy_workqueue(host_dev->handle_error_wq);
2070 * Once we have connected with the host, we would need to
2071 * invoke storvsc_dev_remove() to rollback this state and
2072 * this call also frees up the stor_device; hence the jump around
2075 storvsc_dev_remove(device);
2079 kfree(stor_device->stor_chns);
2083 scsi_host_put(host);
2087 /* Change a scsi target's queue depth */
2088 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2090 if (queue_depth > scsi_driver.can_queue)
2091 queue_depth = scsi_driver.can_queue;
2093 return scsi_change_queue_depth(sdev, queue_depth);
2096 static int storvsc_remove(struct hv_device *dev)
2098 struct storvsc_device *stor_device = hv_get_drvdata(dev);
2099 struct Scsi_Host *host = stor_device->host;
2100 struct hv_host_device *host_dev = shost_priv(host);
2102 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2103 if (host->transportt == fc_transport_template) {
2104 fc_remote_port_delete(stor_device->rport);
2105 fc_remove_host(host);
2108 destroy_workqueue(host_dev->handle_error_wq);
2109 scsi_remove_host(host);
2110 storvsc_dev_remove(dev);
2111 scsi_host_put(host);
2116 static int storvsc_suspend(struct hv_device *hv_dev)
2118 struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2119 struct Scsi_Host *host = stor_device->host;
2120 struct hv_host_device *host_dev = shost_priv(host);
2122 storvsc_wait_to_drain(stor_device);
2124 drain_workqueue(host_dev->handle_error_wq);
2126 vmbus_close(hv_dev->channel);
2128 kfree(stor_device->stor_chns);
2129 stor_device->stor_chns = NULL;
2131 cpumask_clear(&stor_device->alloced_cpus);
2136 static int storvsc_resume(struct hv_device *hv_dev)
2140 ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2141 hv_dev_is_fc(hv_dev));
2145 static struct hv_driver storvsc_drv = {
2146 .name = KBUILD_MODNAME,
2147 .id_table = id_table,
2148 .probe = storvsc_probe,
2149 .remove = storvsc_remove,
2150 .suspend = storvsc_suspend,
2151 .resume = storvsc_resume,
2153 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2157 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2158 static struct fc_function_template fc_transport_functions = {
2159 .show_host_node_name = 1,
2160 .show_host_port_name = 1,
2164 static int __init storvsc_drv_init(void)
2169 * Divide the ring buffer data size (which is 1 page less
2170 * than the ring buffer size since that page is reserved for
2171 * the ring buffer indices) by the max request size (which is
2172 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2174 max_outstanding_req_per_channel =
2175 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2176 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2177 sizeof(struct vstor_packet) + sizeof(u64),
2180 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2181 fc_transport_template = fc_attach_transport(&fc_transport_functions);
2182 if (!fc_transport_template)
2186 ret = vmbus_driver_register(&storvsc_drv);
2188 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2190 fc_release_transport(fc_transport_template);
2196 static void __exit storvsc_drv_exit(void)
2198 vmbus_driver_unregister(&storvsc_drv);
2199 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2200 fc_release_transport(fc_transport_template);
2204 MODULE_LICENSE("GPL");
2205 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2206 module_init(storvsc_drv_init);
2207 module_exit(storvsc_drv_exit);