On 11/03/15 10:59, George Dunlap wrote: > On Tue, Feb 17, 2015 at 10:19 AM, Jan Beulich <jbeul...@suse.com> wrote: >>>>> On 12.02.15 at 03:39, <kai.hu...@linux.intel.com> wrote: >>> On 02/11/2015 07:52 PM, Andrew Cooper wrote: >>>> On 11/02/15 08:28, Kai Huang wrote: >>>>> Design >>>>> ====== >>>>> >>>>> - PML feature is used globally >>>>> >>>>> A new Xen boot parameter, say 'opt_enable_pml', will be introduced to >>>>> control PML feature detection, and PML feature will only be detected >>>>> if opt_enable_pml = 1. Once PML feature is detected, it will be used >>>>> for dirty logging for all domains globally. Currently we don't support >>>>> to use PML on basis of per-domain as it will require additional >>>>> control from XL tool. >>>> Rather than adding in a new top level command line option for an ept >>>> subfeature, it would be preferable to add an "ept=" option which has >>>> "pml" as a sub boolean. >>> Which is good to me, if Jan agrees. >>> >>> Jan, which do you prefer here? >> A single "ept=" option as Andrew suggested. > Sorry to be coming late to this party -- what's the logic behind > having this enabled with "ept="? You're not changing anything about > how EPT itself works; you're adding a secondary feature which happens > to depend on ept. Is there another hypervisor command-line option you > had in mind that works this way?
iommu= > > It might also be nice to be able to enable or disable this feature > with a sysctl call; but that's just a nice-to-have. This feature should either be used or not. It is impractical to enable/disable at runtime. However, it absolutely wants a knob for tweaking. The likely consequence of a bug in the implementation is VM memory corruption on migrate, and you can get away with missing a large amount of a domains memory before it blows up noticeably. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
