From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: IRQs, move_in_progress, -EBUSY &c
Date: Wed, 11 Aug 2010 16:04:40 +0100
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To: George Dunlap <George.Dunlap@eu.citrix.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Jeremy Fitzhardinge <jeremy@goop.org>, Konrad Rzeszutek Wilk <konrad.wilk>
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On 11/08/2010 15:56, "George Dunlap" <George.Dunlap@eu.citrix.com> wrote:

> However, it seems that moving IRQs is not handled properly.  Either
> the pvops kernel should retry if it gets an -EBUSY, or the hypercall
> should not fail, but wait until it can return success.

Move_in_progress is a private hypervisor implementation detail. We shouldn't
make it visible to the guest via EBUSY. Worst case we should be turning the
retry into a hypercall continuation. Even better if we don't need to make
the IRQ bind request wait at all... Not sure why that needs to happen at
all.

 -- Keir

> I discovered all this by adding debug statements to the IRQ path; the
> patch is attached, if anyone else wants to use it.
> 
>  -George