On 1/17/22 06:52, David Gibson wrote:
On Fri, Jan 14, 2022 at 08:07:21AM +0100, Cédric le Goater wrote:
On 1/14/22 00:41, David Gibson wrote:
On Thu, Jan 13, 2022 at 06:51:56PM +0000, Dr. David Alan Gilbert wrote:
Hi,
Is there any easy way of getting a machine where the pbr403 vmstate
would be generated?
The condition in pbr403_needed is...
return (pvr & 0xffff0000) == 0x00200000;
.. which looks to be the PVR for ppc403 models. That makes sense with
the section name... but not so much with the fact that it's under
cpu/tlb6xx. The 6xx MMU is basically unrelated to the 40x MMU. But
it looks like the vmstate_tlbemb might be shared between then, because
of bad ideas of the past.
But in any case, we already dropped what little 403 support we ever
had - there's nothing with that PVR even listed in
target/ppc/cpu-models.h.
So I think we should just drop it.
yes. But we can not remove env.pb since this would break migration
compatibility, correct ?
Only if it appears in a migration section that's actually emitted by a
supported machine type. As far as I can tell the only section that
does that is vmstate_pbr403, which we're also dropping so we should be
fine.
I sent a patch to remove vmstate_pbr403 first.
> It is also touched in the *super* old cpu_load_old. I suspect we
could probably just drop that completely, since I don't think we
realistically support migration from a version that old anyway. But
even if we don't want to do that right now, we can just replace the
reads into env->pb with discarding reads and we'll be fine. We don't
implement any cpus that actually used those fields, so we can ignore
them in the migration stream.
I will take a look at this also with follow ups.
Thanks,
C.
