Re: [Xen-devel] [PATCH] slightly consolidate code in free_domheap_pages()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 20.06.14 at 16:35, <andrew.cooper3@xxxxxxxxxx> wrote:
> On 20/06/14 15:23, Jan Beulich wrote:
>>> Unrelated to the content of the patch, I can't see a codepath where we
>>> would relinquish domain memory from a clean shutdown without setting
>>> d->is_dying.  Does this mean that we are even scrubbing pages from
>>> cleanly shut down domains?
>> Yes, just like the comment says.
> 
> But it means that we will scrub all pages for all domains no matter how
> it died, which is contrary to the statement in the comment which says
> that we don't scrub a cleanly shut down domain.
> 
> From what I can see, the only pages Xen won't scrub are pages handed
> back via decrease reservation, but I don't see how that is relevant in
> this context.

Nothing like this is being said in that comment:

            /*
             * Normally we expect a domain to clear pages before freeing them,
             * if it cares about the secrecy of their contents. However, after
             * a domain has died we assume responsibility for erasure.
             */

("has died" doesn't [to me at least] exclude the clean shutdown case).

Jan


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