From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH][RFC] Support S3 for MSI interrupt in latest kernel dom0 Date: Wed, 17 Dec 2008 15:53:40 +0000 Message-ID: References: <4949294A.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: <4949294A.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: Yunhong Jiang , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 17/12/2008 15:31, "Jan Beulich" wrote: >>>> Keir Fraser 17.12.08 16:22 >>> >> Well, maybe it's okay then. I don't think Yunhong's patch was a good >> argument for it -- looking again it appears to have plenty of not really >> related chunks contained in it. > > I don't think it's really okay as-is: As he indicated, there may be side > effects of the changes during other than resume from S3 (in particular > the IRQ_GUEST check around the newly added call to ->startup()), and > I was hoping you might have a suggestion on how to better distinguish > that particular case. In the worst case, Xen has to set another flag in > each MSI irq_desc when it resumes from S3, and do the startup as well > as the clearing of the flag when map_domain_pirq runs first for that > particular vector. Then do it as a new hypercall? How much complexity does that add on the guest side? -- Keir