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Date: Sun, 27 Sep 2009 12:40:16 +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 10:20 AM, Michael S. Tsirkin wrote:
> On Thu, Sep 24, 2009 at 08:50:11PM +0300, Blue Swirl wrote:
>    
>> On Wed, Sep 23, 2009 at 11:06 PM, Michael S. Tsirkin<mst@redhat.com>  wrote:
>>      
>>> This creates target.c, which builds per-target, and makes it possible
>>> for devices to become target-independent.  Use it in msix, reverting
>>> part of 5e520a7d500ec2569d22d80f9ef4272a34cb3c80, as we no longer have
>>> to pass target page around.
>>>        
>>      
>>> +unsigned target_page_align(unsigned value)
>>> +{
>>> +       return TARGET_PAGE_ALIGN(value);
>>> +}
>>>        
>> This must be:
>> target_phys_addr_t target_page_align(target_phys_addr_t value)
>>      
> 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.  We can have

    target_phys_addr_t target_phys_page_align();
    target_ulong_t target_virt_page_align();

or just

   uint64_t target_page_align();

(which is wasteful on 32/32 guests and 32 hosts).

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