On 2018-03-14, "Robert Paschedag" <robert.pasche...@web.de> wrote:
> Err....do I get it right, that a possibly vulnerable CPU > (from 2016) is still vulnerable to MELTDOWN but a newer > BIOS *fakes* the CPU flags so the MELTDOWN "detection code" > says, "this CPU is NOT vulnerable" > > Is that right? The newer BIOS includes new microcode. As reported by the cpuid 7 edx return, this microcode adds: - IBRS/IBPB speculation control - STIBP speculation control These can be used by the operating system to mitigate Spectre V2 vulnerabilities. - IA32_ARCH_CAPABILITIES model-specific register - RDCL_NO indicator This indicates that the CPU is not vulnerable to Meltdown (V3). The gracious assumption is that the CPU (Apollo Lake/Goldmont) either wasn't vulnerable to Meltdown in the first place or that it could be fixed by the new microcode. -- Christian "naddy" Weisgerber na...@mips.inka.de
