Re: [Qemu-devel] [PATCH 13/15] target-pcc: Convert ppcemb_tlb_t to use fixed 64-bit RPN

[David Gibson <david@gibson.dropbear.id.au>]

On Thu, Oct 18, 2012 at 08:37:20AM +0200, Alexander Graf wrote:
> 
> 
> On 18.10.2012, at 07:50, David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > Currently the ppcemb_tlb_t struct, used on a number of embedded ppc models
> > to represent a TLB entry contains a target_phys_addr_t.  That works
> > reasonably for now, but is troublesome for saving the state, which we'll
> > want to do in future.  target_phys_addr_t is a large enough type to contain
> > a physical address for any supported machine - and can thus, in theory at
> > least, vary depending on what machines are enabled other than the one
> > we're actually using right now.  This makes it unsuitable for describing
> > in vmstate.
> 
> Target_phys_addr_t is actually 64bit for all ppc targets today since
> some 32 bit boards support more than 32 bit address space ;).

Yes, I know.  In fact since recently it's 64bit always on everything.

> The change still is fine though, as it makes that bit explicit.

Yes.  What this is leading to is the new savevm code - there are no
vmstate helpers for target_phys_addr_t and my attempt to add them met
with at least semi-convincing arguments against.

-- 
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