On 21/12/2018 11:27, Jan Beulich wrote: >>>> On 21.12.18 at 12:15, <[email protected]> wrote: >> On 21/12/2018 11:13, Jan Beulich wrote: >>>>>> On 20.12.18 at 18:16, <[email protected]> wrote: >>>> + By default, Xen will use A/D tracking when available in hardware, >>>> except >>>> + on Avoton processors affected by erratum AVR41. Explicitly choosing >>>> + `ad=0` will disable the use of A/D tracking on capable hardware, >>>> whereas >>>> + choosing `ad=1` will cause tracking to be used even on AVR41-affected >>>> + hardware. >>> Is there any reason for this special casing of the one erratum? >>> Earlier this week I've gone through some spec updates for other >>> purposes, and I've seen some rather frightening EPT A/D errata. >> Which, out of interest? There are a few, particularly on Skylake, but >> all the problematic ones I'm aware of are fixed in microcode. > I'd have to go through them again, as I didn't pay close attention to > what was said about their status. Are we generally putting ourselves > on the position then that errata don't need working around if there's > a microcode update available? That's a possible position to take, but > not spelled out anywhere.
Intel and AMD are quite clear that you should be running up-to-date microcode. Its conceptually similar to someone saying "I found an issue in Xen 4.8.0" and our reply being "Thats great, but its already fixed in 4.8.1 - please update". ~Andrew _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
