From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: irq_guest_eoi_timer interaction with MSI Date: Mon, 24 Nov 2008 17:02:47 +0000 Message-ID: References: <492AE5B6.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <492AE5B6.76E4.0078.0@novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 24/11/08 16:34, "Jan Beulich" wrote: > Perhaps the other way around: Make PHYSDEVOP_eoi imply an unmask, > as that's what is always happening (whereas not every unmask also wants > an EOI to be signaled). Below is a draft (compile-tested only) patch that, > before coding the guest side, I'd appreciate to get comments on - > especially if it appears reasonable to be done that way, if it meets your > naming and coding preferences (I'm pretty sure it won't), and of course > whether it's obviously broken in some respect. I don't care which way round you do it (PHYSDEVOP_eoi implies unmask, or vice versa) although you had just about convinced me that you should do it the other way round to how you've chosen. I don't really mind either way though. The fixmap stuff is a bit ugly and I would just have done a map_domain_page_global() for 32-bit Xen (good enough as far as I'm concerned). I'm not dead set against your approach if you like it very much, though. Setting the need-a-hypercall bit looks racey. Don't you need to set the bit, then check the guest didn't unmask meanwhile? -- Keir