From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank van der Linden Subject: Re: Re: [RFC] RAS(Part II)--MCA enalbing in XEN Date: Wed, 25 Feb 2009 10:32:48 -0700 Message-ID: <49A580C0.7050501@Sun.COM> References: <49A45CF0.6080807@Sun.COM> <200902251319.29299.Christoph.Egger@amd.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Return-path: In-reply-to: <200902251319.29299.Christoph.Egger@amd.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: Christoph Egger Cc: "xen-devel@lists.xensource.com" , "Jiang, Yunhong" , "Ke, Liping" , Gavin Maltby , Keir Fraser , "Kleen, Andi" List-Id: xen-devel@lists.xenproject.org Christoph Egger wrote: > On Wednesday 25 February 2009 03:25:12 Jiang, Yunhong wrote: > >> So, Frank/Egger, can I assume followed are consensus currently? >> >> 1) MCE is handled by Xen HV totally, while guest's vMCE handler will only >> works for itself. >> 2) Xen present a virtual #MC to guest through MSR access >> emulation.(Xen will do the translation if needed). >> 3) Guest's unmodified >> MCE handler will handle the vMCE injected. >> 4) Dom0 will get all log/telemetry through hypercall. >> 5) The action taken by xen will be passed to dom0 through the telemetry >> mechanism. > > Mostly. Regarding 2) I want like to discuss first how to handle errors > impacting multiple contiguous physical pages which are non-contigous > in guest physical space. > > And I also want to discuss about how to do recovery actions requiring > PCI access. One example for this is > Shanghai's "L3 Cache Index Disable"-Feature. > Xen delegates PCI config space to Dom0 and > via PCI passthrough partly to DomU. > That means, if registers in PCI config space are independently > accessable by Xen, Dom0 and/or DomU, they can interfere with each other. > Therefore, we need to > a) clearly define who handles what and > b) define some rules based on a) > c) discuss how to handle Dom0/DomU going wild > and break the rules defined in b) I also agree on the approach in principle, but would like to see these points addressed. For non-contiguous pages, I suppose Xen could deliver multiple #vMCEs to the guest, split into contiguous parts. The vmce code seems to be set up to be able to do this. As for the Shanghai feature: Christoph, are there any documents available on that feature? What kind of errors are delivered (corrected/correctable)? - Frank