Re: [Xen-devel] [PATCH] libxc: refactor memory allocation functions

[Juergen Gross <jgross@xxxxxxxx>]

On 01/12/15 12:58, Ian Campbell wrote:
> On Tue, 2015-12-01 at 11:39 +0000, Wei Liu wrote:
>> There were some problems with the original memory allocation functions:
>> 1. xc_dom_alloc_segment and xc_dom_alloc_pad ended up calling
>>    xc_dom_chk_alloc_pages while xc_dom_alloc_page open-coded everything.
>> 2. xc_dom_alloc_pad didn't call dom->allocate.
>>
>> Refactor the code so that:
>> 1. xc_dom_alloc_{segment,pad,page} end up calling
>>    xc_dom_chk_alloc_pages.
>> 2. xc_dom_chk_alloc_pages calls dom->allocate.
>>
>> This way we avoid scattering dom->allocate over multiple locations and
>> open-coding.
>>
>> Also change the return type of xc_dom_alloc_page to xen_pfn_t and return
>> an invalid pfn when xc_dom_chk_alloc_pages fails.
> 
> Given this presumably the handful of callers ought to gain some error
> handling in a followup patch?

I could do that. Wei?

> 
> xc_dom_chk_alloc_pages does log, so at least the callers needn't bother
> with that.
> 
>> Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
> 
> Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> 
>> ---
>> Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
>> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
>> Cc: Juergen Gross <jgross@xxxxxxxx>
>>
>> We don't have INVALID_PFN, maybe we need one?
> 
> We have INVALID_MFN and INVALID_P2M_ENTRY, not sure if the latter fits the
> bill (or if not how it is distinct from the former).

What about merging all of them into INVALID_FRAME?

I can create a patch(-series).


Juergen


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