On 13/02/17 15:30, Jan Beulich wrote: >>>> On 13.02.17 at 16:26, <andrew.coop...@citrix.com> wrote: >> On 13/02/17 15:19, Jan Beulich wrote: >>>>>> On 13.02.17 at 15:32, <andrew.coop...@citrix.com> wrote: >>>> Xen's choice of the MSR_STAR value is constant across all pcpus. >>>> Introduce a >>>> new define and use it to avoid the opencoding in >>>> subarch_percpu_traps_init() >>>> and restore_rest_processor_state(). >>>> >>>> Despite Intel hardware having an MSR_CSTAR register, nothing actually uses >>>> it >>>> as the SYSCALL instruction raises #UD out of 64bit mode, meaning that >>> Did you mean "32-bit"? >> SYSCALL on Intel will #UD if CS.L == 0, so you can't even use it from a >> compatability mode segment. > Right - so my comment stands. Or did you mean "outside of 64-bit > mode"?
I did, but I don't see how that is meaningfully different from what I wrote. OTOH, It doesn't matter as I am dropping that half of the patch. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
