[Qemu-devel] [PATCH 2/8] scsi-disk: Add 'alua_state' property

[Hannes Reinecke <hare@suse.de>]

To support asymmetric logical unit access (ALUA) we need to store
the ALUA state in the device structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 hw/scsi/scsi-bus.c     |  20 +++++++++
 hw/scsi/scsi-disk.c    | 117 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/block/scsi.h   |  13 ++++++
 include/hw/scsi/scsi.h |   8 ++++
 4 files changed, 158 insertions(+)

diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index fd1171e..56a4d33 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1294,6 +1294,21 @@ const struct SCSISense sense_code_LUN_NOT_READY = {
     .key = NOT_READY, .asc = 0x04, .ascq = 0x03
 };
 
+/* LUN not ready, asymmetric access state transition */
+const struct SCSISense sense_code_STATE_TRANSITION = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x0a
+};
+
+/* LUN not ready, target port in standby state */
+const struct SCSISense sense_code_STATE_STANDBY = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x0b
+};
+
+/* LUN not ready, target port in unavailable state */
+const struct SCSISense sense_code_STATE_UNAVAILABLE = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x0c
+};
+
 /* LUN not ready, Medium not present */
 const struct SCSISense sense_code_NO_MEDIUM = {
     .key = NOT_READY, .asc = 0x3a, .ascq = 0x00
@@ -1409,6 +1424,11 @@ const struct SCSISense sense_code_DEVICE_INTERNAL_RESET = {
     .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x04
 };
 
+/* Unit attention, Asymmetric Access State changed */
+const struct SCSISense sense_code_ASYMMETRIC_ACCESS_STATE_CHANGED = {
+    .key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x06
+};
+
 /* Data Protection, Write Protected */
 const struct SCSISense sense_code_WRITE_PROTECTED = {
     .key = DATA_PROTECT, .asc = 0x27, .ascq = 0x00
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index f544f43..583cacd 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -33,6 +33,7 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
 #include "hw/scsi/scsi.h"
 #include "block/scsi.h"
 #include "sysemu/sysemu.h"
+#include "qapi/visitor.h"
 #include "sysemu/block-backend.h"
 #include "sysemu/blockdev.h"
 #include "hw/block/block.h"
@@ -80,6 +81,7 @@ struct SCSIDiskState
     uint64_t port_wwn;
     uint16_t port_index;
     uint16_t port_group;
+    uint8_t alua_state;
     uint64_t max_unmap_size;
     uint64_t max_io_size;
     QEMUBH *bh;
@@ -1890,6 +1892,63 @@ static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf)
         break;
     }
 
+    if ((s->alua_state & 0x0f) != ALUA_STATE_ACTIVE_OPTIMIZED &&
+        (s->alua_state & 0x0f) != ALUA_STATE_ACTIVE_NON_OPTIMIZED) {
+        bool standby_allowed = true;
+        bool unavailable_allowed = true;
+        bool transition_allowed = true;
+
+        switch(req->cmd.buf[0]) {
+        case MAINTENANCE_IN:
+            if ((req->cmd.buf[1] & 31) != MI_REPORT_TARGET_PORT_GROUPS) {
+                transition_allowed = false;
+                unavailable_allowed = false;
+                standby_allowed = false;
+            }
+            /* Fallthrough */
+        case INQUIRY:
+        case REPORT_LUNS:
+        case REQUEST_SENSE:
+            break;
+        case MAINTENANCE_OUT:
+            transition_allowed = false;
+            break;
+        case PERSISTENT_RESERVE_IN:
+        case PERSISTENT_RESERVE_OUT:
+        case LOG_SENSE:
+        case LOG_SELECT:
+        case MODE_SENSE:
+        case MODE_SENSE_10:
+        case MODE_SELECT:
+        case MODE_SELECT_10:
+        case RECEIVE_DIAGNOSTIC:
+        case SEND_DIAGNOSTIC:
+            transition_allowed = false;
+            unavailable_allowed = false;
+            break;
+        default:
+            transition_allowed = false;
+            unavailable_allowed = false;
+            standby_allowed = false;
+            break;
+        }
+        if ((s->alua_state & 0x0f) == ALUA_STATE_STANDBY &&
+            !standby_allowed) {
+            scsi_check_condition(r, SENSE_CODE(STATE_STANDBY));
+            return 0;
+        }
+        if ((s->alua_state & 0x0f) == ALUA_STATE_UNAVAILABLE &&
+            !unavailable_allowed) {
+            scsi_check_condition(r, SENSE_CODE(STATE_UNAVAILABLE));
+            return 0;
+        }
+        if ((s->alua_state & 0x0f) == ALUA_STATE_TRANSITION &&
+            !transition_allowed) {
+            scsi_check_condition(r, SENSE_CODE(STATE_TRANSITION));
+            return 0;
+        }
+    }
+
     /*
      * FIXME: we shouldn't return anything bigger than 4k, but the code
      * requires the buffer to be as big as req->cmd.xfer in several
@@ -2156,6 +2215,21 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
         return 0;
     }
 
+    switch ((s->alua_state & 0x0f)) {
+    case ALUA_STATE_ACTIVE_OPTIMIZED:
+    case ALUA_STATE_ACTIVE_NON_OPTIMIZED:
+        break;
+    case ALUA_STATE_STANDBY:
+        scsi_check_condition(r, SENSE_CODE(STATE_STANDBY));
+        return 0;
+    case ALUA_STATE_UNAVAILABLE:
+        scsi_check_condition(r, SENSE_CODE(STATE_UNAVAILABLE));
+        return 0;
+    case ALUA_STATE_TRANSITION:
+        scsi_check_condition(r, SENSE_CODE(STATE_TRANSITION));
+        return 0;
+    }
+
     len = scsi_data_cdb_xfer(r->req.cmd.buf);
     switch (command) {
     case READ_6:
@@ -2819,11 +2893,54 @@ static void scsi_disk_class_initfn(ObjectClass *klass, void *data)
     dc->vmsd  = &vmstate_scsi_disk_state;
 }
 
+static void scsi_disk_get_alua_state(Object *obj, Visitor *v, void *opaque,
+                                     const char *name, Error **errp)
+{
+    SCSIDiskState *s = OBJECT_CHECK(SCSIDiskState, obj, "scsi-disk");
+    uint8_t alua_state = s->alua_state & 0x0f;
+
+    visit_type_uint8(v, &alua_state, name, errp);
+}
+
+static void scsi_disk_set_alua_state(Object *obj, Visitor *v, void *opaque,
+                                     const char *name, Error **errp)
+{
+    SCSIDiskState *s = OBJECT_CHECK(SCSIDiskState, obj, "scsi-disk");
+    uint8_t alua_state;
+    Error *local_err = NULL;
+
+    visit_type_uint8(v, &alua_state, name, &local_err);
+    if (local_err) {
+        goto out;
+    }
+    if (alua_state > 3) {
+        error_setg(&local_err, "Invalid ALUA state %d\n", alua_state);
+        goto out;
+    }
+
+    s->alua_state = alua_state;
+    scsi_device_set_ua(&s->qdev, SENSE_CODE(ASYMMETRIC_ACCESS_STATE_CHANGED));
+
+out:
+    if (local_err) {
+        error_propagate(errp, local_err);
+    }
+}
+
+static void scsi_disk_instance_initfn(Object *obj)
+{
+    object_property_add(obj, "alua_state", "uint8",
+                        scsi_disk_get_alua_state,
+                        scsi_disk_set_alua_state, NULL, NULL, NULL);
+    object_property_set_int(obj, ALUA_STATE_ACTIVE_OPTIMIZED, "alua_state", NULL);
+}
+
 static const TypeInfo scsi_disk_info = {
     .name          = "scsi-disk",
     .parent        = TYPE_SCSI_DEVICE,
     .instance_size = sizeof(SCSIDiskState),
     .class_init    = scsi_disk_class_initfn,
+    .instance_init = scsi_disk_instance_initfn,
 };
 
 static void scsi_disk_register_types(void)
diff --git a/include/block/scsi.h b/include/block/scsi.h
index a311341..a9d0f64 100644
--- a/include/block/scsi.h
+++ b/include/block/scsi.h
@@ -151,6 +151,11 @@ const char *scsi_command_name(uint8_t cmd);
 #define SAI_READ_CAPACITY_16  0x10
 
 /*
+ * MAINTENANCE IN subcodes
+ */
+#define MI_REPORT_TARGET_PORT_GROUPS 0xa
+
+/*
  * READ POSITION service action codes
  */
 #define SHORT_FORM_BLOCK_ID  0x00
@@ -306,4 +311,12 @@ const char *scsi_command_name(uint8_t cmd);
 #define MMC_PROFILE_HDDVD_RW_DL         0x005A
 #define MMC_PROFILE_INVALID             0xFFFF
 
+#define ALUA_STATE_ACTIVE_OPTIMIZED     0x0
+#define ALUA_STATE_ACTIVE_NON_OPTIMIZED 0x1
+#define ALUA_STATE_STANDBY              0x2
+#define ALUA_STATE_UNAVAILABLE          0x3
+#define ALUA_STATE_LBA_DEPENDENT        0x4
+#define ALUA_STATE_OFFLINE              0xE
+#define ALUA_STATE_TRANSITION           0xF
+
 #endif
diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index cdaf0f8..76f3e49 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -185,6 +185,12 @@ void scsi_bus_legacy_handle_cmdline(SCSIBus *bus, Error **errp);
 extern const struct SCSISense sense_code_NO_SENSE;
 /* LUN not ready, Manual intervention required */
 extern const struct SCSISense sense_code_LUN_NOT_READY;
+/* LUN not ready, asymmetric access state transition */
+extern const struct SCSISense sense_code_STATE_TRANSITION;
+/* LUN not ready, Target Port in standby state */
+extern const struct SCSISense sense_code_STATE_STANDBY;
+/* LUN not ready, Target Port in unavailable state */
+extern const struct SCSISense sense_code_STATE_UNAVAILABLE;
 /* LUN not ready, Medium not present */
 extern const struct SCSISense sense_code_NO_MEDIUM;
 /* LUN not ready, medium removal prevented */
@@ -231,6 +237,8 @@ extern const struct SCSISense sense_code_MEDIUM_CHANGED;
 extern const struct SCSISense sense_code_REPORTED_LUNS_CHANGED;
 /* Unit attention, Device internal reset */
 extern const struct SCSISense sense_code_DEVICE_INTERNAL_RESET;
+/* Unit attention, Asymmetric Access State changed */
+extern const struct SCSISense sense_code_ASYMMETRIC_ACCESS_STATE_CHANGED;
 /* Data Protection, Write Protected */
 extern const struct SCSISense sense_code_WRITE_PROTECTED;
 /* Data Protection, Space Allocation Failed Write Protect */
-- 
1.8.4.5