Re: [Qemu-devel] [Qemu-ppc] [RFC PATCH 1/2] target-ppc: migrate interrupt vectors address for spapr VM

[Greg Kurz]

On Mon, 21 Mar 2016 17:18:17 +0100
Thomas Huth <address@hidden> wrote:

> On 21.03.2016 15:02, Cédric Le Goater wrote:
> > This address is changed by the linux kernel using the H_SET_MODE hcall
> > and needs to be migrated in order to restart a spapr VM running in
> > TCG. Other platforms should not be affected.
> > 
> > Signed-off-by: Cédric Le Goater <address@hidden>
> > ---
> >  target-ppc/machine.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/target-ppc/machine.c b/target-ppc/machine.c
> > index 692121e98319..a418d463db83 100644
> > --- a/target-ppc/machine.c
> > +++ b/target-ppc/machine.c
> > @@ -553,6 +553,9 @@ const VMStateDescription vmstate_ppc_cpu = {
> >          VMSTATE_UINTTL(env.hflags_nmsr, PowerPCCPU),
> >          /* FIXME: access_type? */
> >  
> > +        /* Effective Address of interrupt vectors */
> > +        VMSTATE_UINTTL(env.excp_prefix, PowerPCCPU),
> > +
> >          /* Sanity checking */
> >          VMSTATE_UINTTL_EQUAL(env.msr_mask, PowerPCCPU),
> >          VMSTATE_UINT64_EQUAL(env.insns_flags, PowerPCCPU),  
> 
> I'm really no expert with all this migration stuff, but don't you have
> to bump the version_id when you add new fields to the vmstate?

Yes...

> ... and/or use VMSTATE_UINTTL_V() so that migration from older versions

... and also yes.

> of QEMU to the current one also still works with KVM? For example, is it
> still possible to migrate from QEMU 2.5 to QEMU 2.6 in KVM if you only
> use VMSTATE_UINTTL without the _V suffix?
> 

No we really want to use the _V version here: it indicates that starting with
this version (v6), cpu objects stream env.excp_prefix.

>  Thomas
> 
> 

--
Greg