[Qemu-devel] [PATCH 2/3] 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     | 15 +++++++++++
 hw/scsi/scsi-disk.c    | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/block/scsi.h   | 13 +++++++++
 include/hw/scsi/scsi.h |  6 +++++
 4 files changed, 106 insertions(+)

diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index fd1171e..2096f4c 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
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index f544f43..fbd30f3 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -80,6 +80,7 @@ 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 +1891,60 @@ static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf)
         break;
     }
 
+    if (s->alua_state != ALUA_STATE_ACTIVE_OPTIMIZED &&
+        s->alua_state != 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 == ALUA_STATE_STANDBY && !standby_allowed) {
+            scsi_check_condition(r, SENSE_CODE(STATE_STANDBY));
+            return 0;
+        }
+        if (s->alua_state == ALUA_STATE_UNAVAILABLE && !unavailable_allowed) {
+            scsi_check_condition(r, SENSE_CODE(STATE_UNAVAILABLE));
+            return 0;
+        }
+        if (s->alua_state == 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 +2211,21 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
         return 0;
     }
 
+    switch (s->alua_state) {
+    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:
@@ -2680,6 +2750,7 @@ static Property scsi_hd_properties[] = {
     DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, port_wwn, 0),
     DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
     DEFINE_PROP_UINT16("port_group", SCSIDiskState, port_group, 0),
+    DEFINE_PROP_UINT8("alua_state", SCSIDiskState, alua_state, 0),
     DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
                        DEFAULT_MAX_UNMAP_SIZE),
     DEFINE_PROP_UINT64("max_io_size", SCSIDiskState, max_io_size,
@@ -2797,6 +2868,7 @@ static Property scsi_disk_properties[] = {
     DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, port_wwn, 0),
     DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
     DEFINE_PROP_UINT16("port_group", SCSIDiskState, port_group, 0),
+    DEFINE_PROP_UINT8("alua_state", SCSIDiskState, alua_state, 0),
     DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
                        DEFAULT_MAX_UNMAP_SIZE),
     DEFINE_PROP_UINT64("max_io_size", SCSIDiskState, max_io_size,
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..1574862 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 */
-- 
1.8.4.5