Re: [Qemu-ppc] [PULL 21/38] spapr: Add forgotten capability to migration stream

[Greg Kurz]

On Wed, 22 May 2019 21:10:35 +1000
David Gibson <address@hidden> wrote:

> On Wed, May 22, 2019 at 09:58:29AM +0200, Greg Kurz wrote:
> > On Wed, 22 May 2019 14:45:43 +1000
> > David Gibson <address@hidden> wrote:
> >   
> > > spapr machine capabilities are supposed to be sent in the migration stream
> > > so that we can sanity check the source and destination have compatible
> > > configuration.  Unfortunately, when we added the hpt-max-page-size
> > > capability, we forgot to add it to the migration state.  This means that 
> > > we
> > > can generate spurious warnings when both ends are configured for large
> > > pages, or potentially fail to warn if the source is configured for huge
> > > pages, but the destination is not.
> > > 
> > > Fixes: 2309832afda "spapr: Maximum (HPT) pagesize property"
> > > 
> > > Signed-off-by: David Gibson <address@hidden>
> > > Reviewed-by: Cédric Le Goater <address@hidden>
> > > ---  
> > 
> > Huh... we discussed that it was breaking backward migration:
> > 
> > https://lists.gnu.org/archive/html/qemu-ppc/2019-05/msg00330.html
> > 
> > So I'm a bit surprised to see this in the PR... is it intentional ?  
> 
> Sod, no, I forgot to remove it from my tree.
> 
> Having been through the test cycle, I'd prefer not to hold up the PR
> for this - as long as we fix it before the release we should be ok.
> 

Fair enough, I'll re-post my fix proposal in a proper patch ASAP.

> >   
> > >  hw/ppc/spapr.c         | 1 +
> > >  hw/ppc/spapr_caps.c    | 1 +
> > >  include/hw/ppc/spapr.h | 1 +
> > >  3 files changed, 3 insertions(+)
> > > 
> > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > index 8580a8dc67..bcae30ad26 100644
> > > --- a/hw/ppc/spapr.c
> > > +++ b/hw/ppc/spapr.c
> > > @@ -2125,6 +2125,7 @@ static const VMStateDescription vmstate_spapr = {
> > >          &vmstate_spapr_cap_cfpc,
> > >          &vmstate_spapr_cap_sbbc,
> > >          &vmstate_spapr_cap_ibs,
> > > +        &vmstate_spapr_cap_hpt_maxpagesize,
> > >          &vmstate_spapr_irq_map,
> > >          &vmstate_spapr_cap_nested_kvm_hv,
> > >          &vmstate_spapr_dtb,
> > > diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> > > index 9b1c10baa6..658eb15a14 100644
> > > --- a/hw/ppc/spapr_caps.c
> > > +++ b/hw/ppc/spapr_caps.c
> > > @@ -703,6 +703,7 @@ SPAPR_CAP_MIG_STATE(dfp, SPAPR_CAP_DFP);
> > >  SPAPR_CAP_MIG_STATE(cfpc, SPAPR_CAP_CFPC);
> > >  SPAPR_CAP_MIG_STATE(sbbc, SPAPR_CAP_SBBC);
> > >  SPAPR_CAP_MIG_STATE(ibs, SPAPR_CAP_IBS);
> > > +SPAPR_CAP_MIG_STATE(hpt_maxpagesize, SPAPR_CAP_HPT_MAXPAGESIZE);
> > >  SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
> > >  SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
> > >  SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> > > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> > > index 7e32f309c2..9fc91c8f5e 100644
> > > --- a/include/hw/ppc/spapr.h
> > > +++ b/include/hw/ppc/spapr.h
> > > @@ -849,6 +849,7 @@ extern const VMStateDescription vmstate_spapr_cap_dfp;
> > >  extern const VMStateDescription vmstate_spapr_cap_cfpc;
> > >  extern const VMStateDescription vmstate_spapr_cap_sbbc;
> > >  extern const VMStateDescription vmstate_spapr_cap_ibs;
> > > +extern const VMStateDescription vmstate_spapr_cap_hpt_maxpagesize;
> > >  extern const VMStateDescription vmstate_spapr_cap_nested_kvm_hv;
> > >  extern const VMStateDescription vmstate_spapr_cap_large_decr;
> > >  extern const VMStateDescription vmstate_spapr_cap_ccf_assist;  
> >   
>

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