ahci: ncq migration

Migrate the NCQ queue. This is solely for the benefit of halted commands,
since anything else should have completed and had any relevant status
flushed to the HBA registers already.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1435767578-32743-13-git-send-email-jsnow@redhat.com

hw/ide/ahci.c

@@ -1521,6 +1521,21 @@ void ahci_reset(AHCIState *s)
     }
 }
 
+static const VMStateDescription vmstate_ncq_tfs = {
+    .name = "ncq state",
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(sector_count, NCQTransferState),
+        VMSTATE_UINT64(lba, NCQTransferState),
+        VMSTATE_UINT8(tag, NCQTransferState),
+        VMSTATE_UINT8(cmd, NCQTransferState),
+        VMSTATE_UINT8(slot, NCQTransferState),
+        VMSTATE_BOOL(used, NCQTransferState),
+        VMSTATE_BOOL(halt, NCQTransferState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static const VMStateDescription vmstate_ahci_device = {
     .name = "ahci port",
     .version_id = 1,
@@ -1546,14 +1561,17 @@ static const VMStateDescription vmstate_ahci_device = {
         VMSTATE_BOOL(done_atapi_packet, AHCIDevice),
         VMSTATE_INT32(busy_slot, AHCIDevice),
         VMSTATE_BOOL(init_d2h_sent, AHCIDevice),
+        VMSTATE_STRUCT_ARRAY(ncq_tfs, AHCIDevice, AHCI_MAX_CMDS,
+                             1, vmstate_ncq_tfs, NCQTransferState),
         VMSTATE_END_OF_LIST()
     },
 };
 
 static int ahci_state_post_load(void *opaque, int version_id)
 {
-    int i;
+    int i, j;
     struct AHCIDevice *ad;
+    NCQTransferState *ncq_tfs;
     AHCIState *s = opaque;
 
     for (i = 0; i < s->ports; i++) {
@@ -1565,6 +1583,37 @@ static int ahci_state_post_load(void *opaque, int version_id)
             return -1;
         }
 
+        for (j = 0; j < AHCI_MAX_CMDS; j++) {
+            ncq_tfs = &ad->ncq_tfs[j];
+            ncq_tfs->drive = ad;
+
+            if (ncq_tfs->used != ncq_tfs->halt) {
+                return -1;
+            }
+            if (!ncq_tfs->halt) {
+                continue;
+            }
+            if (!is_ncq(ncq_tfs->cmd)) {
+                return -1;
+            }
+            if (ncq_tfs->slot != ncq_tfs->tag) {
+                return -1;
+            }
+            /* If ncq_tfs->halt is justly set, the engine should be engaged,
+             * and the command list buffer should be mapped. */
+            ncq_tfs->cmdh = get_cmd_header(s, i, ncq_tfs->slot);
+            if (!ncq_tfs->cmdh) {
+                return -1;
+            }
+            ahci_populate_sglist(ncq_tfs->drive, &ncq_tfs->sglist,
+                                 ncq_tfs->cmdh, ncq_tfs->sector_count * 512,
+                                 0);
+            if (ncq_tfs->sector_count != ncq_tfs->sglist.size >> 9) {
+                return -1;
+            }
+        }
+
+
         /*
          * If an error is present, ad->busy_slot will be valid and not -1.
          * In this case, an operation is waiting to resume and will re-check