Re: [Qemu-devel] [PATCH 14/15] memory: return MemoryRegion from qemu_ram_addr_from_host

[Paolo Bonzini <pbonzini@redhat.com>]

Il 03/06/2013 08:40, Paolo Bonzini ha scritto:
> Il 02/06/2013 18:04, Peter Maydell ha scritto:
>> On 2 June 2013 16:43, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>> -int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
>>> +MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
>>>  ram_addr_t qemu_ram_addr_from_host_nofail(void *ptr);
>>
>> This is weird, because now the _nofail and the standard
>> versions of this function return different things.

Ah, actually that's not a change.  The function used to return 0/-1 and
place the address in a by-reference argument.  It's a somewhat weird
decision made when the normal and _nofail version were split (commit
e890261, Export qemu_ram_addr_from_host, 2010-10-11).  Returning -1 to
indicate failure would have been ok, since it's not a valid ram_addr_t.

>> Why wouldn't a caller of the _nofail version potentially
>> need the MemoryRegion* too?

Because there are just a handful of calls, and all of them are in
cputlb.c which is not very much MemoryRegion-aware.  I'll just move it
there and make it static.

The right fix here would be to make all the MCE handling code not
KVM-specific.  Then it can be in exec.c and ram_addr_t can be private
(eliminating a good deal of confusion between it and hwaddr).

Paolo