Il 28/10/2012 20:40, Marcelo Tosatti ha scritto:
>
> qemu-kvm 1.2 -> qemu-1.3 migration fails with
>
> Unknown savevm section type 48
> load of migration failed
>
> Due to a fix in acpi_piix4 in qemu-kvm (attached at the end of the
> message).
>
> The problem is that qemu-kvm correctly uses 2 bytes for sts and
> 2 bytes for en fields (which is their allocated size), while qemu
> uses 4*2 bytes for each.
>
> The fix present in qemu-kvm is correct, but, having it in qemu 1.3 would break
> qemu 1.2 -> qemu 1.3 migration (while allowing qemu-kvm 1.2 -> qemu 1.3
> migration).
>
> Any opinions on what to do?
Bump the .version_id and .minimum_version_id to 2 and load the QEMU 1.2
state via .load_state_old.
qemu-kvm 1.2 -> qemu 1.3 migration would be broken. qemu-kvm
downstreams that care can leave .minimum_version_id to 1.
Paolo
> >>
> >> +#define VMSTATE_GPE_ARRAY(_field, _state) \
> >> + { \
> >> + .name = (stringify(_field)), \
> >> + .version_id = 0, \
> >> + .num = GPE_LEN, \
> >> + .info =&vmstate_info_uint16, \
> >> + .size = sizeof(uint16_t), \
> >> + .flags = VMS_ARRAY | VMS_POINTER, \
> >> + .offset = vmstate_offset_pointer(_state, _field, uint8_t), \
> >> + }
> >> +
> >> static const VMStateDescription vmstate_gpe = {
> >> .name = "gpe",
> >> .version_id = 1,
> >> .minimum_version_id = 1,
> >> .minimum_version_id_old = 1,
> >> .fields = (VMStateField []) {
> >> - VMSTATE_UINT16(sts, struct gpe_regs),
> >> - VMSTATE_UINT16(en, struct gpe_regs),
> >> + VMSTATE_GPE_ARRAY(sts, ACPIGPE),
> >> + VMSTATE_GPE_ARRAY(en, ACPIGPE),
> >> VMSTATE_END_OF_LIST()
> >> }
> >> };
> >
> > I'm no vmstate expert, but this does look odd. Why both VMS_ARRAY and
> > VMS_POINTER? aren't we trying to save/restore a simple 16-bit value? Or
> > at least we did before this patch.
>
> That's right. the difference is, the new member type became uint8_t*.
> Does the following help?
>
> Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
>
> diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
> index d65a7e9..9dc6f43 100644
> --- a/hw/acpi_piix4.c
> +++ b/hw/acpi_piix4.c
> @@ -221,10 +221,9 @@ static int vmstate_acpi_post_load(void *opaque, int version_id)
> { \
> .name = (stringify(_field)), \
> .version_id = 0, \
> - .num = GPE_LEN, \
> .info = &vmstate_info_uint16, \
> .size = sizeof(uint16_t), \
> - .flags = VMS_ARRAY | VMS_POINTER, \
> + .flags = VMS_SINGLE | VMS_POINTER, \
> .offset = vmstate_offset_pointer(_state, _field, uint8_t), \
> }
>
>
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
