Messages in this thread | | | Date | Wed, 13 Sep 2023 12:21:23 -0400 | Subject | Re: [PATCH] Revert "EDAC/mce_amd: Do not load edac_mce_amd module on guests" | From | Yazen Ghannam <> |
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On 9/13/23 11:50 AM, Luck, Tony wrote: >> Also, please note that the EDAC modules don't handle MCE events >> directly. They act on information passed from the MCE subsystem. >> >> Furthermore, there are other EDAC modules that have the same !hypervisor >> check, so why change only this one? > > The older Intel EDAC drivers translated system physical addresses to DIMM > addresses by digging around in the CONFIG and MMIO space of the memory > controller devices. It would seem unwise for a VMM to give access to those > addresses to a guest (in general ... perhaps OK for a Xen style "DOM0" guest that is > handling many tasks for the VMM?). > > What system resources do AMD EDAC drivers need access to? Could they > work inside a guest? >
The MCE decoder may access some newer MCA registers, or request info from the MCE subsystem. But this is for informational error decoding. It won't support any actions that a guest could take.
The AMD64 EDAC module reads system-specific memory controller registers through non-architectural interfaces. So also unwise or not useful for a guest to access.
Thanks, Yazen
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