scsi: Fix migration of scsi sense data

c5f52875 changed the size of sense array in vmstate_scsi_device by
mistake. This patch restores the old size, and add a subsection for the
remaining part of the buffer size. So that migration is not broken.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-bus.c

@@ -1905,6 +1905,26 @@ static const VMStateInfo vmstate_info_scsi_requests = {
     .put  = put_scsi_requests,
 };
 
+static bool scsi_sense_state_needed(void *opaque)
+{
+    SCSIDevice *s = opaque;
+
+    return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
+}
+
+static const VMStateDescription vmstate_scsi_sense_state = {
+    .name = "SCSIDevice/sense",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
+                                SCSI_SENSE_BUF_SIZE_OLD,
+                                SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_scsi_device = {
     .name = "SCSIDevice",
     .version_id = 1,
@@ -1915,7 +1935,7 @@ const VMStateDescription vmstate_scsi_device = {
         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
-        VMSTATE_UINT8_ARRAY(sense, SCSIDevice, SCSI_SENSE_BUF_SIZE),
+        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
         VMSTATE_UINT32(sense_len, SCSIDevice),
         {
             .name         = "requests",
@@ -1927,6 +1947,14 @@ const VMStateDescription vmstate_scsi_device = {
             .offset       = 0,
         },
         VMSTATE_END_OF_LIST()
+    },
+    .subsections = (VMStateSubsection []) {
+        {
+            .vmsd = &vmstate_scsi_sense_state,
+            .needed = scsi_sense_state_needed,
+        }, {
+            /* empty */
+        }
     }
 };
 

include/hw/scsi/scsi.h

@@ -31,6 +31,7 @@ typedef struct SCSISense {
     uint8_t ascq;
 } SCSISense;
 
+#define SCSI_SENSE_BUF_SIZE_OLD 96
 #define SCSI_SENSE_BUF_SIZE 252
 
 struct SCSICommand {

include/migration/vmstate.h

@@ -650,6 +650,9 @@ extern const VMStateInfo vmstate_info_bitmap;
 #define VMSTATE_UINT8_ARRAY(_f, _s, _n)                               \
     VMSTATE_UINT8_ARRAY_V(_f, _s, _n, 0)
 
+#define VMSTATE_UINT8_SUB_ARRAY(_f, _s, _start, _num)                \
+    VMSTATE_SUB_ARRAY(_f, _s, _start, _num, 0, vmstate_info_uint8, uint8_t)
+
 #define VMSTATE_UINT8_2DARRAY(_f, _s, _n1, _n2)                       \
     VMSTATE_UINT8_2DARRAY_V(_f, _s, _n1, _n2, 0)