On Tue, Nov 05, 2024 at 10:10:20AM -0800, Sean Christopherson wrote: > All of the actual maintainers. Which maintainers do you mean? tip ones? If so, they're all shorted to x86@xxxxxxxxxx. > AFAIK, Paolo doesn't subscribe to kvm@. Oh boy, srsly?! I thought I'd reach the proper crowd with kvm@xxxxxxxxxxxxxxx... > > Meh, I can split them if you really want me to. > > I do. Sure, next revision. > What does the bit actually do? I can't find any useful documentation, and the > changelog is equally useless. "Processors which set SRSO_MSR_FIX=1 support an MSR bit which mitigates SRSO across guest/host boundaries. Software may enable this by setting bit 4 (BpSpecReduce) of MSR C001_102E. This bit can be set once during boot and should be set identically across all processors in the system." From: https://www.amd.com/content/dam/amd/en/documents/corporate/cr/speculative-return-stack-overflow-whitepaper.pdf I think that's the only public info we have on that bit. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette
