From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH RFC 22/31] x86/cpu: Move set_cpumask() calls into c_early_init() Date: Thu, 21 Jan 2016 10:08:18 -0700 Message-ID: <56A11E9202000078000C9BC7@prv-mh.provo.novell.com> References: <1450301073-28191-1-git-send-email-andrew.cooper3@citrix.com> <1450301073-28191-23-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1450301073-28191-23-git-send-email-andrew.cooper3@citrix.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper Cc: Xen-devel List-Id: xen-devel@lists.xenproject.org >>> On 16.12.15 at 22:24, wrote: > Before c/s 44e24f8567 "x86: don't call generic_identify() redundantly", the > commandline-provided masks would take effect in Xen's view of the features. > > As the masks got applied after the query for features, the redundant call to > generic_identify() would clobber the wrong feature information with the new, > correct information. I don't think "wrong" is appropriate here, since ... > Move the set_cpumask() calls into c_early_init() so their effects take place > before the main query for features in generic_identify(). > > The cpuid_mask_* command line parameters now correctly limit the entire > system, ... I consider this wrong (both Xen and Dom0 can benefit from using features an admin may want to mask for migration purposes), the more ... > although the subsequent changes will replace the need to use these > parameters for heterogeneous levelling purposes. ... that you then make clear this won't be needed anymore. Jan