This only breaks backwards migration compatibility if the bus is in an error state. It is in principle possible to avoid this by making two subsections (one for version 1, and one for version 2, but with the same name) with different "_needed" callbacks. The v1 callback would return true if error_status != 0 and the bus is PATA; the v2 callback would return true if error_status != 0 and the bus is AHCI.
Forward migration keeps working. Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- hw/ide/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/ide/core.c b/hw/ide/core.c index d3f2c4f..01deeeb 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -2544,11 +2544,14 @@ const VMStateDescription vmstate_ide_drive = { static const VMStateDescription vmstate_ide_error_status = { .name ="ide_bus/error", - .version_id = 1, + .version_id = 2, .minimum_version_id = 1, .minimum_version_id_old = 1, .fields = (VMStateField []) { VMSTATE_INT32(error_status, IDEBus), + VMSTATE_INT64_V(retry_sector_num, IDEBus, 2), + VMSTATE_UINT32_V(retry_nsector, IDEBus, 2), + VMSTATE_UINT8_V(retry_unit, IDEBus, 2), VMSTATE_END_OF_LIST() } }; -- 1.8.3.1