>>> On 10.04.18 at 11:32, <jgr...@suse.com> wrote: > On 10/04/18 11:14, Jan Beulich wrote: >>>>> On 10.04.18 at 09:58, <jgr...@suse.com> wrote: >>> --- a/docs/misc/xen-command-line.markdown >>> +++ b/docs/misc/xen-command-line.markdown >>> @@ -1955,14 +1955,29 @@ clustered mode. The default, given no hint from >>> the **FADT**, is cluster >>> mode. >>> >>> ### xpti >>> -> `= <boolean>` >>> +> `= List of [ default | <boolean> | dom0=<bool> | domu=<bool> ]` >>> >>> -> Default: `false` on AMD hardware >>> +> Default: `false` on hardware not vulnerable to Meltdown (e.g. AMD) >>> > Default: `true` everywhere else >>> >>> Override default selection of whether to isolate 64-bit PV guest page >>> tables. >>> >>> +`true` activates page table isolation even on hardware not vulnerable by >>> +Meltdown for all domains. >>> + >>> +`false` deactivates page table isolation on all systems for all domains. >>> + >>> +`default` sets the default behaviour. >>> + >>> +`dom0=false` deactivates page table isolation for dom0. >>> + >>> +`dom0=true` activates page table isolation for dom0. >>> + >>> +`domu=false` deactivates page table isolation for guest domains. >>> + >>> +`domu=true` activates page table isolation for guest domains. >> >> This is too verbose / repetitive for my taste. > > So you'd like it better as: > > "With `dom0` and `domu` it is possible to control page table isolation > for dom0 or guest domains only." ?
Yes. >>> @@ -205,6 +208,10 @@ int pv_domain_initialise(struct domain *d) >>> /* 64-bit PV guest by default. */ >>> d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 0; >>> >>> + d->arch.pv_domain.xpti = (d->domain_id == hardware_domid) >>> + ? (opt_xpti & XPTI_DOM0) >>> + : (opt_xpti & XPTI_DOMU); >> >> I would generally prefer to have as little redundancy as possible in >> such expressions, i.e. >> >> d->arch.pv_domain.xpti = opt_xpti & (d->domain_id == hardware_domid >> ? XPTI_DOM0 : XPTI_DOMU); > > Okay. > >> >> Furthermore - shouldn't this cover domain 0 as well as the hardware >> domain, even if - in case they are different - domain 0 should be >> short lived? > > When domain 0 is created is _is_ the hardware domain. Only domain 0 > creating a hardware domain will set hardware_domid to a non-zero value. hardware_domid is set by an integer_param() afaics, so would be set long before creation of domain 0. Jan _______________________________________________ Xen-devel mailing list Xenemail@example.com https://lists.xenproject.org/mailman/listinfo/xen-devel