On 28/02/2022 10:20, Jan Beulich wrote: > Not even the types were correct,
Huh yes. c/s 97638f08f4 was plain wrong. > let alone defaults being spelled out or > the purpose of the options actually mentioned in any way. > > Signed-off-by: Jan Beulich <[email protected]> > > --- a/docs/misc/xen-command-line.pandoc > +++ b/docs/misc/xen-command-line.pandoc > @@ -1681,10 +1681,21 @@ one pending bit to be allocated. > Defaults to 20 bits (to cover at most 1048576 interrupts). > > ### mce (x86) > -> `= <integer>` > +> `= <boolean>` > + > +> Default: `true` > + > +Allows to disable the use of Machine Check Exceptions. Note that this > +may result in silent shutdown of the system in case an event occurs > +which would have resulted in raising a Machine Check Exception. This description appears backwards. Errors happen irrespective of MCE, and will by default cause a system shutdown. MCE offers the OS/VMM some ability to deal with certain not-totally-fatal errors in a less impactful way than killing the whole system. Also, it allows reporting of corrected errors which are indicative of failing components. Also, it's not silent - the MCE registers explicitly don't clear on reset so they can be recovered after warm reset. Firmware collects these and is supposed to do something useful with them, although "useful" is a matter of opinion, and in some cases depends on how much extra you're willing to pay your OEM. ~Andrew
