From 7544abf3b783fc82b031d40d0685d2047709492a Mon Sep 17 00:00:00 2001 From: Jason Baron 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 Signed-off-by: Michael S. Tsirkin (cherry picked from commit 1de53459272d89c52bb21b45d5d970de40fbb642) Signed-off-by: Michael Roth --- 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