Add a framework to manage and cache KVM-governed features, i.e. CPUID based features that require explicit KVM enabling and/or need to be queried semi-frequently by KVM. The idea originally came up in the context of the architectural LBRs series as a way to avoid querying guest CPUID in hot paths without needing a dedicated flag, but as evidenced by the shortlog, the most common usage is to handle the ever- growing list of SVM features that are exposed to L1. The first six patches are fixes and cleanups related to TSC scaling. nSVM has WARN_ONs that can be triggered by userspace at will, and the code is a bit crusty. They aren't directly related to the governed stuff, I stumbled upon the issues they fix when staring at the patch to convert "TSC scaling enabled". I included them here mainly to avoid code conflicts. I'm hoping all of this can go into 6.6, e.g. so that CET support can build on guest_can_use(), but I can always grab the TSC patches for 6.6 if the governed stuff needs more time. Note, I still don't like the name "governed", but no one has suggested anything else, let alone anything better :-) v2: - Add patches to clean up TSC scaling. - Add a comment explaining the virtual VMLOAD/VMLAVE vs. SYSENTER on Intel madness. - Use a governed feature for X86_FEATURE_VMX. - Incorporate KVM capabilities into the main check-and-set helper. [Chao] v1: https://lore.kernel.org/all/20230217231022.816138-1-seanjc@xxxxxxxxxx Sean Christopherson (21): KVM: nSVM: Check instead of asserting on nested TSC scaling support KVM: nSVM: Load L1's TSC multiplier based on L1 state, not L2 state KVM: nSVM: Use the "outer" helper for writing multiplier to MSR_AMD64_TSC_RATIO KVM: SVM: Clean up preemption toggling related to MSR_AMD64_TSC_RATIO KVM: x86: Always write vCPU's current TSC offset/ratio in vendor hooks KVM: nSVM: Skip writes to MSR_AMD64_TSC_RATIO if guest state isn't loaded KVM: x86: Add a framework for enabling KVM-governed x86 features KVM: x86/mmu: Use KVM-governed feature framework to track "GBPAGES enabled" KVM: VMX: Recompute "XSAVES enabled" only after CPUID update KVM: VMX: Check KVM CPU caps, not just VMX MSR support, for XSAVE enabling KVM: VMX: Rename XSAVES control to follow KVM's preferred "ENABLE_XYZ" KVM: x86: Use KVM-governed feature framework to track "XSAVES enabled" KVM: nVMX: Use KVM-governed feature framework to track "nested VMX enabled" KVM: nSVM: Use KVM-governed feature framework to track "NRIPS enabled" KVM: nSVM: Use KVM-governed feature framework to track "TSC scaling enabled" KVM: nSVM: Use KVM-governed feature framework to track "vVM{SAVE,LOAD} enabled" KVM: nSVM: Use KVM-governed feature framework to track "LBRv enabled" KVM: nSVM: Use KVM-governed feature framework to track "Pause Filter enabled" KVM: nSVM: Use KVM-governed feature framework to track "vGIF enabled" KVM: nSVM: Use KVM-governed feature framework to track "vNMI enabled" KVM: x86: Disallow guest CPUID lookups when IRQs are disabled arch/x86/include/asm/kvm_host.h | 23 ++++++++- arch/x86/include/asm/vmx.h | 2 +- arch/x86/kvm/cpuid.c | 34 ++++++++++++++ arch/x86/kvm/cpuid.h | 46 ++++++++++++++++++ arch/x86/kvm/governed_features.h | 21 +++++++++ arch/x86/kvm/mmu/mmu.c | 20 ++------ arch/x86/kvm/svm/nested.c | 57 ++++++++++++---------- arch/x86/kvm/svm/svm.c | 81 ++++++++++++++++++-------------- arch/x86/kvm/svm/svm.h | 18 ++----- arch/x86/kvm/vmx/capabilities.h | 2 +- arch/x86/kvm/vmx/hyperv.c | 2 +- arch/x86/kvm/vmx/nested.c | 13 ++--- arch/x86/kvm/vmx/nested.h | 2 +- arch/x86/kvm/vmx/vmx.c | 81 +++++++++++++++----------------- arch/x86/kvm/vmx/vmx.h | 3 +- arch/x86/kvm/x86.c | 9 ++-- 16 files changed, 261 insertions(+), 153 deletions(-) create mode 100644 arch/x86/kvm/governed_features.h base-commit: fdf0eaf11452d72945af31804e2a1048ee1b574c -- 2.41.0.487.g6d72f3e995-goog
