On Thu, Apr 05, 2018 at 02:06:19PM +0200, Greg Kurz wrote: > On Thu, 5 Apr 2018 12:14:33 +1000 > David Gibson <da...@gibson.dropbear.id.au> wrote: > > > Currently env->mmu_model is a bit of an unholy mess of an enum of distinct > > MMU types, with various flag bits as well. This makes which bits of the > > field should be compared pretty confusing. > > > > Make a start on cleaning that up by moving two of the flags bits - > > POWERPC_MMU_1TSEG and POWERPC_MMU_AMR - which are specific to the 64-bit > > hash MMU into a new flags field in PPCHash64Options structure. > > > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > > Reviewed-by: Cédric Le Goater <c...@kaod.org> > > Reviewed-by: Greg Kurz <gr...@kaod.org> > > --- > > While investigating a migration failure from an older QEMU, I realized > this patch has a problem. The *cpu->hash64_opts structure is zeroed in > kvm_fixup_page_sizes(), which has now the unwanted effect of clearing > the cpu->hash64_opts->flags as well. > > We only need to zero the segment page sizes actually. The following > fixes migration: > > @@ -442,7 +442,7 @@ static void kvm_fixup_page_sizes(PowerPCCPU *cpu) > } > > /* Convert to QEMU form */ > - memset(cpu->hash64_opts, 0, sizeof(*cpu->hash64_opts)); > + memset(&cpu->hash64_opts->sps, 0, sizeof(cpu->hash64_opts->sps)); > > /* If we have HV KVM, we need to forbid CI large pages if our > * host page size is smaller than 64K.
Ah, good catch. I mistakenly thought that kvm_fixup_page_sizes() was
completely rewriting those flags as well. I've made this fix now.
I'm also currently working on some other patches which amongst other
things get rid of kvm_fixup_page_sizes(), because it's completely
broken by design. But might as well not break things excessively in
the meantime.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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