Hi Rafael, Len, Looks like I should have CC'd you on this patch. This is probably something we should get into 5.8-rc2, so that it can then get put into stable kernels, as some people think this is security sensitive. Bigger picture is this: https://data.zx2c4.com/american-unsigned-language-2.gif https://data.zx2c4.com/american-unsigned-language-2-fedora-5.8.png Also, somebody mentioned to me that Microsoft's ACPI implementation disallows writes to system memory as a security mitigation. I haven't looked at what that actually entails, but I wonder if entirely disabling support for ACPI_ADR_SPACE_SYSTEM_MEMORY would be sensible. I haven't looked at too many DSDTs. Would that break real hardware, or does nobody do that? Alternatively, the range of acceptable addresses for SystemMemory could exclude kernel memory. Would that break anything? Have you heard about Microsoft's mitigation to know more details on what they figured out they could safely restrict without breaking hardware? Either way, food for thought I suppose. Jason
