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 12:27:52 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Jiang, Yunhong" , Jan Beulich , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 17/12/2008 12:11, "Jiang, Yunhong" wrote: > In latest kernel, the pci_save_state will not try to save msi/x_state anymore, > instead, it will try to restore msi state when resume using kernel's msi data > structure. This cause trouble for us, since thoese MSI data structure is > meaningless in Xen environment. > > Several option to resolve this issue: > a) Change the latest kernel (as dom0) to still to save/restore the msi content > b) Add a new hypercall, so when dom0 try to restore dom0, it will instruct Xen > HV to restore the content based on Xen's MSI data structure Could Xen remember the MSI state automatically, as it does for IO-APIC presumably already? It knows what vectors are routed where at least, even if dom0 has to reprogram the PCI device itself. I'm not sure about option C. I didn't really understand the patch, but it smelt like a hack. -- Keir