esp: fix setting of ESPState mig_version_id when launching QEMU with -S option

If QEMU is launched with the -S option then the ESPState mig_version_id property
is left unset due to the ordering of the VMState fields in the VMStateDescription
for sysbusespscsi and pciespscsi. If the VM is migrated and restored in this
stopped state, the version tests in the vmstate_esp VMStateDescription and
esp_post_load() become confused causing the migration to fail.

Fix the ordering problem by moving the setting of mig_version_id to a common
esp_pre_save() function which is invoked first by both sysbusespscsi and
pciespscsi rather than at the point where ESPState is itself serialised into the
migration stream.

Buglink: https://bugs.launchpad.net/qemu/+bug/1922611
Fixes: 0bd005be78 ("esp: add vmstate_esp version to embedded ESPState")
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210407124842.32695-1-mark.cave-ayland@ilande.co.uk>

diff --git a/hw/scsi/esp-pci.c b/hw/scsi/esp-pci.c
index c3d3dab05eae391fe3cbf9343a43e0d09474fbab..9db10b1a48767c8a6d741c5bbf49e571d021521a 100644 (file)
--- a/hw/scsi/esp-pci.c
+++ b/hw/scsi/esp-pci.c
@@ -332,6 +332,7 @@ static const VMStateDescription vmstate_esp_pci_scsi = {
     .name = "pciespscsi",
     .version_id = 2,
     .minimum_version_id = 1,
+    .pre_save = esp_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, PCIESPState),
         VMSTATE_BUFFER_UNSAFE(dma_regs, PCIESPState, 0, 8 * sizeof(uint32_t)),

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 507ab363bce01e567c2517160ff62bda68db79a6..d87e1a63dbd44b9fd506f819c5e241d7860ec8ed 100644 (file)
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -1076,9 +1076,10 @@ static bool esp_is_version_5(void *opaque, int version_id)
     return version_id == 5;
 }
 
-static int esp_pre_save(void *opaque)
+int esp_pre_save(void *opaque)
 {
-    ESPState *s = ESP(opaque);
+    ESPState *s = ESP(object_resolve_path_component(
+                      OBJECT(opaque), "esp"));
 
     s->mig_version_id = vmstate_esp.version_id;
     return 0;
@@ -1114,7 +1115,6 @@ const VMStateDescription vmstate_esp = {
     .name = "esp",
     .version_id = 5,
     .minimum_version_id = 3,
-    .pre_save = esp_pre_save,
     .post_load = esp_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_BUFFER(rregs, ESPState),
@@ -1304,6 +1304,7 @@ static const VMStateDescription vmstate_sysbus_esp_scsi = {
     .name = "sysbusespscsi",
     .version_id = 2,
     .minimum_version_id = 1,
+    .pre_save = esp_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8_V(esp.mig_version_id, SysBusESPState, 2),
         VMSTATE_STRUCT(esp, SysBusESPState, 0, vmstate_esp, ESPState),

diff --git a/include/hw/scsi/esp.h b/include/hw/scsi/esp.h
index 95088490aa563d64b523ddb8c9fb1918a607dd23..aada3680b7577778841d669105b9bf4b51c6a63d 100644 (file)
--- a/include/hw/scsi/esp.h
+++ b/include/hw/scsi/esp.h
@@ -157,5 +157,6 @@ void esp_hard_reset(ESPState *s);
 uint64_t esp_reg_read(ESPState *s, uint32_t saddr);
 void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val);
 extern const VMStateDescription vmstate_esp;
+int esp_pre_save(void *opaque);
 
 #endif