On 26.03.2025 11:18, Roger Pau Monné wrote: > On Wed, Mar 26, 2025 at 10:45:18AM +0100, Jan Beulich wrote: >> On 26.03.2025 10:21, Roger Pau Monné wrote: >>> On Wed, Mar 26, 2025 at 09:45:09AM +0100, Jan Beulich wrote: >>>> Further tables on said system >>>> which weren't blacklisted prior to that commit, yet which also aren't >>>> whitelisted are DBGP, DBG2, FIDT, LPIT, MIGT, MSCT, NITR, PCCT, RASF, >>>> SVOS, UEFI, WDDT, and WSMT. Even without diving into the details of any >>>> of them it seems pretty clear to me that at least some would want >>>> whitelisting, too. >>> >>> I cannot find any reference about: FIDT, MIGT, NITR, SVOS and WDDT in >>> the ACPI spec. >> >> WDDT - Watchdog Descriptor Table (Table 5.6 in spec version 6.5) >> >>> The MSCT I think we don't want to expose, as it's related to topology >>> data. >>> >>> Regarding RASF I would be slightly worried about the patrol scrub >>> feature. The memory map exposed to dom0 will be different from the >>> native one, and there's also the interposed p2m. >> >> Thing is - either kind of Dom0 needs to have a sufficient level of insight >> into the host memory map to support memory-related RAS features. Which may >> mean that RASF may only be exposed if the Dom0 kernel declares itself as >> aware of the need to consider data there to refer to a separate address >> space. > > Yes, but then, how is a PVH dom0 going to be aware of such addresses? > Given the automatic translation of gfn -> mfn that's completely hidden > from dom0.
Right, but the knowledge is going to be necessary there, I expect. > I'm not saying it can't be done, but I think RASF shouldn't be exposed > to a PVH dom0 until we understand how such feature is supposed to work > with the interposed p2m and the fabricated memory map available to a > PVH dom0. Note a PVH dom0 can still get the host memory map from the > XENMEM_machine_memory_map hypercall. Oh, of course I agree we can't expose such without first having dealt with the implications. Jan
