Re: [Qemu-devel] [PATCH 3/5] pc: future-proof migration-compatibility of ACPI tables

[Michael S. Tsirkin]

On Mon, Jul 28, 2014 at 06:08:53PM +0200, Paolo Bonzini wrote:
> Il 28/07/2014 17:59, Michael S. Tsirkin ha scritto:
> > On Mon, Jul 28, 2014 at 05:34:16PM +0200, Paolo Bonzini wrote:
> >> This patch avoids that similar changes break QEMU again in the future.
> >> QEMU will now hard-code 64k as the maximum ACPI table size, which
> >> (despite being an order of magnitude smaller than 640k) should be enough
> >> for everyone.
> > 
> > Famous last words :) So what worries me here, is that we
> > are potentially breaking legal configurations for the
> > benefit of the minority that cares about cross-version
> > migration.
> > 
> > So I'm inclined to apply everything except this patch, and
> > instead, use the patches that I sent to make the
> > ram block very large, something like 1 Megabyte.
> 
> Even just 128k are enough for 160 VCPUs, 255 memory slots and 35-40 PCI
> bridges.  And for 2.2 I'd rather move to the other model where all
> user-defined elements (MADT, SSDT) are in a separate file and we
> guarantee that *all* changes are versioned by machine type.
> 
> What do you think about just changing 64k->128k?  Your patch is a huge
> amount of code for -rc4.
> 
> Paolo

True ...

OK I applied this, and made minor tweaks on top.
Any reviewers?

-- 
MST