Re: [Xen-devel] [PATCH v2 3/3] [GSOC14] FIX:- Race condition between initializing shared ring and mempaging.

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2014-07-21 at 15:40 +0100, Andrew Cooper wrote:

> > 
> > Note that the XSA commmit, 6ae2df93c27, does exactly that. Enable
> > paging/access/sharing, and only after that decrease reservation (and
> > after that unpause). So the window is open ... methinks?
> 
> No - it does a domain pause around this set of critical operations, so
> the guest is guaranteed not to be running, and therefore cannot
> interfere.

Shouldn't there be a memset in here somewhere? To clear out any bogus
material in the ring? (maybe the caller of this code always clears the
ring itself, I didn't check that)

Ian.


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