commit 0bd005be782d9492afe3cc6fc494d8c3b477e5b8
author Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Thu Mar 04 22:10:25 2021 +0000
committer Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Sun Mar 07 10:39:05 2021 +0000
tree 934a3b98e8d92410f08af9b4c5e025b3060369b0
parent eb169c76d092b289a6a150b725e8fb2de990379b

esp: add vmstate_esp version to embedded ESPState

The QOM object representing ESPState is currently embedded within both the
SYSBUS_ESP and PCI_ESP devices with migration state handled by embedding
vmstate_esp within each device using VMSTATE_STRUCT.

Since the vmstate_esp fields are embedded directly within the migration
stream, the incoming vmstate_esp version_id is lost. The only version information
available is that from vmstate_sysbus_esp_scsi and vmstate_esp_pci_scsi, but
those versions represent their respective devices and not that of the underlying
ESPState.

Resolve this by adding a new version-dependent field in vmstate_sysbus_esp_scsi
and vmstate_esp_pci_scsi which stores the vmstate_esp version_id field within
ESPState to be used to allow migration from older QEMU versions.

Finally bump the vmstate_esp version to 5 to cover the upcoming ESPState changes
within this patch series.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-5-mark.cave-ayland@ilande.co.uk>

hw/scsi/esp.c

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 6f8a1d1..f65c675 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -795,10 +795,28 @@
     }
 };
 
+static int esp_pre_save(void *opaque)
+{
+    ESPState *s = ESP(opaque);
+
+    s->mig_version_id = vmstate_esp.version_id;
+    return 0;
+}
+
+static int esp_post_load(void *opaque, int version_id)
+{
+    ESPState *s = ESP(opaque);
+
+    s->mig_version_id = vmstate_esp.version_id;
+    return 0;
+}
+
 const VMStateDescription vmstate_esp = {
     .name = "esp",
-    .version_id = 4,
+    .version_id = 5,
     .minimum_version_id = 3,
+    .pre_save = esp_pre_save,
+    .post_load = esp_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_BUFFER(rregs, ESPState),
         VMSTATE_BUFFER(wregs, ESPState),
@@ -997,9 +1015,10 @@
 
 static const VMStateDescription vmstate_sysbus_esp_scsi = {
     .name = "sysbusespscsi",
-    .version_id = 1,
+    .version_id = 2,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
+        VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),
         VMSTATE_END_OF_LIST()
     }