On 9/5/19 12:01 PM, Roger Pau Monné wrote: > On Thu, Sep 05, 2019 at 12:34:11PM +0200, George Dunlap wrote: >> >> >>> On Sep 5, 2019, at 11:01 AM, Roger Pau Monne <roger....@citrix.com> wrote: >>> >>> On Thu, Sep 05, 2019 at 11:52:59AM +0200, Jan Beulich wrote: >>>> On 05.09.2019 11:34, Roger Pau Monne wrote: >>>>> Current libxl code will always enable Hardware Assisted Paging (HAP), >>>>> expecting that the hypervisor will fallback to shadow if HAP is not >>>>> available. With the changes to the domain builder that's not the case >>>>> any longer, and the hypervisor will raise an error if HAP is not >>>>> available instead of silently falling back to shadow. >>>> >>>> Would it really be much more involved than the change here to restore >>>> silent defaulting to shadow? >>> >>> But that would mean that a user having selected hap=1 on the config >>> file would get silently defaulted to shadow, which is wrong IMO. >> >> At the libxl layer, aren’t the options tristate? I.e., this would be “hap”, >> “shadow”, or “not specified”? >> >> The user needs to be able to specify “always use shadow”, “always use HAP”, >> or “use HAP if available, otherwise use shadow”. > > The "use HAP if available, otherwise use shadow" is currently only > possibly expressed by not setting the hap option in the config file. > >> At the moment, leaving it empty should be “use HAP if available, otherwise >> use shadow”; so “hap = 1” should fail if HAP is not available. > > Right, this is what this patch is trying to accomplish.
Right; I wasn't trying to contradict you so much as "weigh in" (and basically agree with you). -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
