Re: [Xen-devel] I cannot get any message from domU by console / pv_ops domU kernel crashes with xen_create_contiguous_region failed

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Tue, 2009-12-22 at 15:47 +0000, Konrad Rzeszutek Wilk wrote:
> > I thought it used to be that you could only (successfully) make order>0
> > increase_reservation or mem_exchange hypercalls if you had I/O
> > privileges? Has this changed?
> 
> I am looking at the 3.4 code I am not seeing any I/O privileges check.
> 
> I did not even know that those existed actually - could you give me an idea
> when was the last time you saw it?

In xen-unstable multipage_allocation_permitted is called from
memory_exchange() and increase_reservation() and is defined as 
#define multipage_allocation_permitted(d, order)        \
    (((order) <= 9) || /* allow 2MB superpages */       \
     !rangeset_is_empty((d)->iomem_caps) ||             \
     !rangeset_is_empty((d)->arch.ioport_caps))

The ((order) <= 9) || is new and isn't present in the 3.4 tree,
previously you would have had to add a passthrough device to cause one
of the other rangesets to become non-empty. 

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel