On 12/08/2019 15:53, George Dunlap wrote: > On 8/8/19 10:13 AM, Julien Grall wrote: >> Hi Jan, >> >> On 08/08/2019 10:04, Jan Beulich wrote: >>> On 08.08.2019 10:43, Andrew Cooper wrote: >>>> On 08/08/2019 07:22, Jan Beulich wrote: >>>>> On 07.08.2019 21:41, Andrew Cooper wrote: >>>>>> --- /dev/null >>>>>> +++ b/docs/glossary.rst >>>>>> @@ -0,0 +1,37 @@ >>>>>> +Glossary >>>>>> +======== >>>>>> + >>>>>> +.. Terms should appear in alphabetical order >>>>>> + >>>>>> +.. glossary:: >>>>>> + >>>>>> + control domain >>>>>> + A :term:`domain`, commonly dom0, with the permission and >>>>>> responsibility >>>>>> + to create and manage other domains on the system. >>>>>> + >>>>>> + domain >>>>>> + A domain is Xen's unit of resource ownership, and generally has >>>>>> at the >>>>>> + minimum some RAM and virtual CPUs. >>>>>> + >>>>>> + The terms :term:`domain` and :term:`guest` are commonly used >>>>>> + interchangeably, but they mean subtly different things. >>>>>> + >>>>>> + A guest is a single virtual machine. >>>>>> + >>>>>> + Consider the case of live migration where, for a period of >>>>>> time, one >>>>>> + guest will be comprised of two domains, while it is in transit. >>>>>> + >>>>>> + domid >>>>>> + The numeric identifier of a running :term:`domain`. It is >>>>>> unique to a >>>>>> + single instance of Xen, used as the identifier in various APIs, >>>>>> and is >>>>>> + typically allocated sequentially from 0. >>>>>> + >>>>>> + guest >>>>>> + See :term:`domain` >>>>> I think you want to mention the usual distinction here: Dom0 is, >>>>> while a domain, commonly not considered a guest. >>>> To be honest, I had totally forgotten about that. I guess now is the >>>> proper time to rehash it in public. >>>> >>>> I don't think the way it currently gets used has a clear or coherent set >>>> of rules, because I can't think of any to describe how it does get used. >>>> >>>> Either there are a clear and coherent (and simple!) set of rules for >>>> what we mean by "guest", at which point they can live here in the >>>> glossary, or the fuzzy way it is current used should cease. >>> What's fuzzy about Dom0 not being a guest (due to being a part of the >>> host instead)? >> Dom0 is not part of the host if you are using an hardware domain. I >> actually thought we renamed everything in Xen from Dom0 to hwdom to >> avoid the confusion. >> >> I also would rather avoid to treat "dom0" as not a guest. In normal >> setup this is a more privilege guest, in other setup this may just be a >> normal guest (think about partitioning). > A literal guest is someone who doesn't live in the building (or work in > the buliding, if you're in a hotel). The fact that the staff cleaning > rooms are restricted in their privileges doesn't make them guests of the > hotel. > > The toolstack domain, the hardware domain, the driver domain, the > xenstore domain, and so on are all part of the host system, designed to > allow you to use Xen to do the thing you actually want to do: Run guests. > > And it's important that we have a word that distinguishes "domains that > we only care about because they make it possible to run other domains", > and "domains that we actually want to run". "guest / host" is a natural > terminology for these. > > We already have the word "domain", which includes dom0, driver domains, > toolstack domains, hardware domains, as well as guest domains. We don't > need "guest" to be a synonym for "domain".
So... Please can someone propose wording simple, clear wording for what "guest" means. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
