From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] [SVM]: Make 32bit legacy guests boot again Date: Mon, 29 Jun 2009 10:17:39 +0100 Message-ID: References: <200906291040.00326.Christoph.Egger@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200906291040.00326.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" List-Id: xen-devel@lists.xenproject.org I forgot to push. Should be there now. -- Keir On 29/06/2009 09:39, "Christoph Egger" wrote: > > Tnx. I will check as soon as it appears in the public staging tree. > > Christoph > > > On Saturday 27 June 2009 11:35:20 Keir Fraser wrote: >> Changeset 19856 is a cleaned up and streamlined version of this patch. >> Please take a look. It also fixes a couple of largely theoretical issues: >> * Should depend on EFER.LMA not EFER.LME >> * Should handle the LMA 1->0 transition (i.e., return to legacy mode). >> >> -- Keir >> >> On 26/06/2009 16:19, "Christoph Egger" wrote: >>> Hi! >>> >>> Attached patch fixes a bug introduced in c/s 19648. >>> >>> 32bit legacy guests have the sysenter/sysexit instructions available. >>> Therefore, we have to disable intercepts for the sysenter MSRs or the >>> guest stucks in an infinite loop of #GPs, otherwise. >>> >>> For guests in 64bit mode and 32bit compat mode, sysenter/sysexit >>> instructions aren't available. The sysenter MSRs have to be intercepted >>> to make the instruction emulation working. >>> >>> Attach patch first assumes the guest is in 32bit legacy mode and >>> therefore disables the sysenter MSRs in construct_vmcb(). >>> Access to the MSR_EFER is intercepted. When the guest enables longmode, >>> then enable interception of the sysenter MSRs. >>> >>> Signed-off-by: Christoph Egger > >