On 6/24/20 4:54 PM, Sean Christopherson wrote: >> Does this actually work? >> >> The node span (->node_start_pfn through start+->node_spanned_pages) only >> contains pages which the OS is actively managing, usually RAM but >> sometimes also persistent memory. This has some assumption that the SGX >> PFNs are within the node's span. I would only _expect_ that to happen >> if the node was built like this: >> >> | Node-X RAM | EPC | Node-X RAM | >> >> If the EPC was on either end: >> >> | Node-X RAM | EPC | >> or >> | EPC | Node-X RAM | >> >> I suspect that the pgdat span wouldn't include EPC. EPC is, if I >> remember correctly, a E820_RESERVED region. > It is indeed E820_RESERVED, but the BIOS WG for ICX states that EPC regions > should be enumerated in ACPI SRAT along with regular memory. > > But, I haven't actually verified that info makes its way into the kernel's > pgdata stuff. Considering this, are we all agreed that this patch is in no condition to be submitted upstream?
