qemu/0113-pcie-drop-version_id-field-for-live-migration.patch
2012-10-28 14:05:07 -04:00

80 lines
3.0 KiB
Diff

From 7544abf3b783fc82b031d40d0685d2047709492a Mon Sep 17 00:00:00 2001
From: Jason Baron <jbaron@redhat.com>
Date: Wed, 8 Aug 2012 14:29:12 -0400
Subject: [PATCH] pcie: drop version_id field for live migration
While testing q35 live migration, I found that the migration would abort with
the following error: "Unknown savevm section type 76".
The error is due to this check failing in 'vmstate_load_state()':
while(field->name) {
if ((field->field_exists &&
field->field_exists(opaque, version_id)) ||
(!field->field_exists &&
field->version_id <= version_id)) {
The VMSTATE_PCIE_DEVICE() currently has a 'version_id' set to 2. However,
'version_id' in the above check is 1. And thus we fail to load the pcie device
field. Further the code returns to 'qemu_loadvm_state()' which produces the
error that I saw.
I'm proposing to fix this by simply dropping the 'version_id' field from
VMSTATE_PCIE_DEVICE(). VMSTATE_PCI_DEVICE() defines no such field and further
the vmstate_pcie_device that VMSTATE_PCI_DEVICE() refers to is already
versioned. Thus, any versioning issues could be detected at the vmsd level.
Taking a step back, I think that the 'field->version_id' should be compared
against a saved version number for the field not the 'version_id'. Futhermore,
once vmstate_load_state() is called recursively on another vmsd, the check of:
if (version_id > vmsd->version_id) {
return -EINVAL;
}
Will never fail since version_id is always equal to vmsd->version_id. So I'm
wondering why we aren't storing the vmsd version id of the source in the
migration stream?
This patch also renames the 'name' field of vmstate_pcie_device from:
PCIDevice -> PCIEDevice to differentiate it from vmstate_pci_device.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 1de53459272d89c52bb21b45d5d970de40fbb642)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
hw/pci.c | 2 +-
hw/pcie.h | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/hw/pci.c b/hw/pci.c
index 4d95984..f855cf3 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -439,7 +439,7 @@ const VMStateDescription vmstate_pci_device = {
};
const VMStateDescription vmstate_pcie_device = {
- .name = "PCIDevice",
+ .name = "PCIEDevice",
.version_id = 2,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
diff --git a/hw/pcie.h b/hw/pcie.h
index b8ab0c7..4889194 100644
--- a/hw/pcie.h
+++ b/hw/pcie.h
@@ -133,7 +133,6 @@ extern const VMStateDescription vmstate_pcie_device;
#define VMSTATE_PCIE_DEVICE(_field, _state) { \
.name = (stringify(_field)), \
- .version_id = 2, \
.size = sizeof(PCIDevice), \
.vmsd = &vmstate_pcie_device, \
.flags = VMS_STRUCT, \
--
1.7.12.1