On 06/16/16 11:51, Paolo Bonzini wrote:
>
>
> On 16/06/2016 08:06, Haozhong Zhang wrote:
> > Migration is only allowed between VCPUs with the same lmce option.
> >
> > Signed-off-by: Haozhong Zhang <[email protected]>
> > ---
> > target-i386/machine.c | 25 +++++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> >
> > diff --git a/target-i386/machine.c b/target-i386/machine.c
> > index cb9adf2..00375a3 100644
> > --- a/target-i386/machine.c
> > +++ b/target-i386/machine.c
> > @@ -347,6 +347,12 @@ static int cpu_post_load(void *opaque, int version_id)
> > return -EINVAL;
> > }
> >
> > + if (!cpu->enable_lmce && (env->mcg_cap & MCG_LMCE_P)) {
> > + error_report("Config mismatch: VCPU has LMCE enabled, "
> > + "but \"lmce\" option is disabled");
> > + return -EINVAL;
> > + }
> > +
>
> I think this is unnecessary. Apart from this, the patch is good and can
> be squashed in patch 1 for v5.
>
Without this check, the migration from LMCE enabled QEMU to LMCE
disabled QEMU will not fail. Is such configuration change considered
be error? If not, I will remove the error report and return, but add a
fix to remove MCG_LMCE_P from env->mcg_cap in this check.
Haozhong
>
> > /*
> > * Real mode guest segments register DPL should be zero.
> > * Older KVM version were setting it wrongly.
> > @@ -896,6 +902,24 @@ static const VMStateDescription vmstate_tsc_khz = {
> > }
> > };
> >
> > +static bool mcg_ext_ctl_needed(void *opaque)
> > +{
> > + X86CPU *cpu = opaque;
> > + CPUX86State *env = &cpu->env;
> > + return cpu->enable_lmce && env->mcg_ext_ctl;
> > +}
> > +
> > +static const VMStateDescription vmstate_mcg_ext_ctl = {
> > + .name = "cpu/mcg_ext_ctl",
> > + .version_id = 1,
> > + .minimum_version_id = 1,
> > + .needed = mcg_ext_ctl_needed,
> > + .fields = (VMStateField[]) {
> > + VMSTATE_UINT64(env.mcg_ext_ctl, X86CPU),
> > + VMSTATE_END_OF_LIST()
> > + }
> > +};
> > +
> > VMStateDescription vmstate_x86_cpu = {
> > .name = "cpu",
> > .version_id = 12,
> > @@ -1022,6 +1046,7 @@ VMStateDescription vmstate_x86_cpu = {
> > #ifdef TARGET_X86_64
> > &vmstate_pkru,
> > #endif
> > + &vmstate_mcg_ext_ctl,
> > NULL
> > }
> > };
> >
