From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v2 2/5] VMX/Viridian: suppress MSR-based APIC suggestion when having APIC-V Date: Tue, 25 Jun 2013 14:43:34 +0100 Message-ID: <51C99E86.1020506@eu.citrix.com> References: <51C8092A02000078000DFDA0@nat28.tlf.novell.com> <51C80BB202000078000DFDB2@nat28.tlf.novell.com> <9AAE0902D5BC7E449B7C8E4E778ABCD0051253@LONPEX01CL01.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9AAE0902D5BC7E449B7C8E4E778ABCD0051253@LONPEX01CL01.citrite.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Paul Durrant Cc: "Keir (Xen.org)" , Jan Beulich , Eddie Dong , xen-devel , Jun Nakajima , Yang Z Zhang List-Id: xen-devel@lists.xenproject.org On 06/25/2013 11:29 AM, Paul Durrant wrote: >> -----Original Message----- >> From: Jan Beulich [mailto:JBeulich@suse.com] >> Sent: 24 June 2013 08:05 >> To: xen-devel >> Cc: Paul Durrant; George Dunlap; Eddie Dong; Jun Nakajima; Yang Z Zhang; >> Keir (Xen.org) >> Subject: [PATCH v2 2/5] VMX/Viridian: suppress MSR-based APIC suggestion >> when having APIC-V >> >> When the CPU has the necessary capabilities, having Windows use >> synthetic MSR reads/writes is bogus, as this still requires emulation >> (which is pretty much guaranteed to be slower than having the hardware >> carry out the operation). >> >> Signed-off-by: Jan Beulich >> > > Seems better just to not use the MSR in this case so I favour this patch over #1, hence > > Ack-ed by: Paul Durrant This may push this over into the "#2 is probably a better idea" category; Paul, Yang, and Jan all think it's less intrusive. Jan, I think it's your call -- You have an ack from me to put either #1 or #2 in for 4.3 (but please not both). -George