From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: machine check support in HVM guests Date: Mon, 27 Nov 2006 15:49:15 +0000 Message-ID: References: <456B0B71.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <456B0B71.76E4.0078.0@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 , Keir Fraser Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 27/11/06 14:59, "Jan Beulich" wrote: >> No, I'm not saying that. I was simply expecting that it would be easy to >> fake out a very minimal machine-check emulation where nothing ever goes >> wrong. :-) If that involves GPFing on some MSR accesses, those are easy to >> inject into an HVM guest I believe. > > That wasn't my concern, I know that's simple. But the guest may not be > prepared to handle a GP fault here - after all, if CPUID says MCA is > supported, there is no reason the guest should use recovery methods > around accessing the respective MSRs. Likewise, if returning zero, the > guest may BUG(), as it may (validly) assert there's at least one bank of > MSRs supported. And so on... Then we support one bank of MSRs, store writes to those (so the contents can be read back) but do not act on the writes? I never got the impression machine check setup was very complicated. -- Keir