Re: [Xen-devel] Re: how to handle paged hypercall args?

[Keir Fraser <keir@xxxxxxx>]

On 11/11/2010 14:33, "Olaf Hering" <olaf@xxxxxxxxx> wrote:

> So is that an acceptable way to deal with the HVMCOPY_gfn_paged_out
> return codes from __hvm_copy?
> Or should I explore some different way, like spinning there and possible
> let other threads-of-execution make progress while waiting for the gfns
> to come back?

You can't just spin because Xen is not preemptible. If it were a single CPU
system for example, no other thread would ever run again. You have to 'spin'
via a preemptible loop that returns to guest context and then back into the
hypercall. Which appears to be what you're doing.

 -- Keir



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