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Date: Sun, 27 Sep 2009 13:55:17 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] Re: [PATCHv2] qemu: target library, use it in msix
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, qemu-devel@nongnu.org

On 09/27/2009 01:45 PM, Michael S. Tsirkin wrote:
>
>    
>>> Thinking about this some more, this function just says "align a value to
>>> page size". The value might not be a bus address at all, and indeed with
>>> msix use, it is not. Makes sense?
>>>
>>>        
>> In any case restricting it to unsigned invites truncation.
>>      
> If the value we are aligning fits in 32 bit, so does the aligned value.
>    

It's perfectly reasonable to call a such a function with a 
target_ulong_t or target_phys_addr_t input and expect it to work.

>>   We can have
>>
>>     target_phys_addr_t target_phys_page_align();
>>     target_ulong_t target_virt_page_align();
>>      
> Right. And also
>     target_page_align32();
>     target_page_align64();
>
> We only use a 32 bit version now (passed value is a constant),
> so I think I'll only implement it, and we'll add more when
> they are used.
>    

How would the caller know what size argument they have?  They usually 
have a target_phys_addr_t or a target_ulong_t.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.