Re: [Qemu-devel] [PATCH] build: fix target_phys_addr_t to 64-bit

[Peter Maydell <peter.maydell@linaro.org>]

On 12 January 2012 20:32, Anthony Liguori <anthony@codemonkey.ws> wrote:
> On 01/12/2012 02:06 PM, Peter Maydell wrote:
>>
>> On 12 January 2012 17:54, Anthony Liguori<aliguori@us.ibm.com>  wrote:
>>>
>>> This simplifies the build quite a bit and improves the builds performance
>>> by
>>> not rebuilding many objects twice.
>>>
>>> There were a surprising number of places that had assumed wrong things
>>> about the
>>> size of target_phys_addr_t including that it was fixed at 32-bit and that
>>> it
>>> was identical to target_ulong.
>>
>>
>> Up until now, in a lot of CPU-specific code it has been perfectly
>> reasonable to assume target_phys_addr_t was 32 bits.
>
>
> No, that's never been a reasonable thing to assume.

Having target_phys_addr_t be possibly larger than the guest
physical address type is exactly the thing this patch is
changing...

>> I don't like this. When target_phys_addr_t was 32 bits, then
>> using TARGET_FMT_plx to print offsets into devices isn't
>> too unreasonable as you only get 8 hex digits. If you expand
>> to 64 bits then suddenly all these offsets which are actually
>> really typically small numbers get printed as 16 hex digits,
>> which I think looks bad.

> Then cast it to a 32-bit number and print it however you like.

You're the one changing what was previously a known-to-be-32-bit
type to one that's much bigger, you get to fix the printing
issues.

-- PMM