On 3/24/21 8:40 PM, Dr. David Alan Gilbert wrote: > * Philippe Mathieu-Daudé ([email protected]) wrote: >> When adding the Reset register in commit 5790b757cfb we >> forgot to migrate it. >> >> While it is possible a VM using the PIIX4 is migrated just >> after requesting a system shutdown, it is very unlikely. >> However when restoring a migrated VM, we might have the >> RCR bit #4 set on the stack and when the VM resume it >> directly shutdowns. >> >> Add a post_load() migration handler and set the default >> RCR value to 0 for earlier versions, assuming the VM was >> not going to shutdown before migration. >> >> Fixes: 5790b757cfb ("piix4: Add the Reset Control Register") >> Signed-off-by: Philippe Mathieu-Daudé <[email protected]> >> --- >> v2: Add piix4_ide_post_load() and describe >> --- >> hw/isa/piix4.c | 15 ++++++++++++++- >> 1 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/hw/isa/piix4.c b/hw/isa/piix4.c >> index a50d97834c7..e7bce0e590c 100644 >> --- a/hw/isa/piix4.c >> +++ b/hw/isa/piix4.c >> @@ -93,12 +93,25 @@ static void piix4_isa_reset(DeviceState *dev) >> pci_conf[0xae] = 0x00; >> } >> >> +static int piix4_ide_post_load(void *opaque, int version_id) >> +{ >> + PIIX4State *s = opaque; >> + >> + if (version_id == 2) { >> + s->rcr = 0; >> + } >> + >> + return 0; >> +} >> + >> static const VMStateDescription vmstate_piix4 = { >> .name = "PIIX4", >> - .version_id = 2, >> + .version_id = 3, >> .minimum_version_id = 2, >> + .post_load = piix4_ide_post_load, >> .fields = (VMStateField[]) { >> VMSTATE_PCI_DEVICE(dev, PIIX4State), >> + VMSTATE_UINT8(rcr, PIIX4State), > > I don't think that looks right any more; you'd need to make that a > VMSTATE_UINT8_V(rcr, PIIX4State, 3), > > I think, otherwise when you loaded a v2 it would still try > and read the rcr byte.
Ah now I guess I understood. Thanks!
