From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kai Huang Subject: Re: PML (Page Modification Logging) design for Xen Date: Tue, 24 Mar 2015 16:17:16 +0800 Message-ID: <55111D8C.8050204@linux.intel.com> References: <54DB129D.3060102@linux.intel.com> <54DB4294.1080406@citrix.com> <54DC1249.60507@linux.intel.com> <54E323C7020000780006089B@mail.emea.novell.com> <5511075D.8010006@linux.intel.com> <55112601020000780006CD5B@mail.emea.novell.com> <55111AE8.1040603@linux.intel.com> <55112B05020000780006CD8C@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55112B05020000780006CD8C@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Andrew Cooper , kevin.tian@intel.com, tim@xen.org, keir@xen.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 03/24/2015 04:14 PM, Jan Beulich wrote: >>>> On 24.03.15 at 09:06, wrote: >> On 03/24/2015 03:53 PM, Jan Beulich wrote: >>> The command line >>> option parsing is (and should be) independent of the chosen >>> default anyway, i.e. overrides in either direction should be >>> possible. >> While the parse_ept_param function does support "ept=pml" and >> "ept=no-pml" both, I think in the comments of the function we should >> explicitly tell whether to use "ept=pml" (in case PML is off by >> default), or "ept=no-pml" (in case PML is on by default), otherwise >> "ept=pml,no-pml" is legal but obviously it doesn't make any sense (and >> looks this issue also exists in parse_iommu_param?). > While "ept=pml,no-pml" makes little sense, there's nothing wrong > with allowing it. "ept=pml ept=no-pml" may in fact make sense, > when wanting to override a setting e.g. in an EFI config file on > the command (or grub) line. IOW don't lose time on preventing > non-sense option combinations if the resulting settings > nevertheless are valid / meaningful. Hmm. Reasonable indeed. Thanks. Thanks, -Kai > > Jan >