Re: [Xen-devel] Re: xen crash in tmem: checking a xen pfn for domain ownership

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 20/09/2010 08:16, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

>>>> On 17.09.10 at 21:32, Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:
>> Oh, depending on what you want to do with the page you may well want to
>> get_page(current->domain, page). You don't hold a lock on the domain's p2m,
>> so page ownerships can change under your feet, and hence getting a reference
>> to the page, and checking the page's ownership at the same time, might be
>> wise. And if you want to modify the page you should probably use
>> get_page_and_type(..., PGT_writable_page).
> 
> That's particularly important for the pv case, where gfn_to_mfn() is
> a no-op.

Yes, I actually forgot about the PV case, and I think that's the only case
that matters for tmem. :-)

 -- Keir



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