[PATCH 0/9] KVM: x86: Replace governed features with guest cpu_caps

From: Sean Christopherson
Date: Fri Nov 10 2023 - 18:55:45 EST


Replace the poorly named, confusing, and high-maintenance "governed
features" framework with a comprehensive guest cpu_caps implementation.

In short, snapshot all X86_FEATURE_* flags that KVM cares about so that
all queries against guest capabilities are "fast", e.g. don't require
manual enabling or judgment calls as to where a feature needs to be fast.

The guest_cpu_cap_* nomenclature follows the existing kvm_cpu_cap_*
except for a few (maybe just one?) cases where guest cpu_caps need APIs
that kvm_cpu_caps don't. In theory, the similar names will make this
approach more intuitive.

Sean Christopherson (9):
KVM: x86: Rename "governed features" helpers to use "guest_cpu_cap"
KVM: x86: Replace guts of "goverened" features with comprehensive
cpu_caps
KVM: x86: Initialize guest cpu_caps based on guest CPUID
KVM: x86: Avoid double CPUID lookup when updating MWAIT at runtime
KVM: x86: Drop unnecessary check that cpuid_entry2_find() returns
right leaf
KVM: x86: Update guest cpu_caps at runtime for dynamic CPUID-based
features
KVM: x86: Shuffle code to prepare for dropping guest_cpuid_has()
KVM: x86: Replace all guest CPUID feature queries with cpu_caps check
KVM: x86: Restrict XSAVE in cpu_caps based on KVM capabilities

arch/x86/include/asm/kvm_host.h | 40 ++++++----
arch/x86/kvm/cpuid.c | 102 +++++++++++++++++++-------
arch/x86/kvm/cpuid.h | 121 +++++++++++--------------------
arch/x86/kvm/governed_features.h | 21 ------
arch/x86/kvm/lapic.c | 2 +-
arch/x86/kvm/mmu/mmu.c | 4 +-
arch/x86/kvm/mtrr.c | 2 +-
arch/x86/kvm/reverse_cpuid.h | 15 ----
arch/x86/kvm/smm.c | 10 +--
arch/x86/kvm/svm/nested.c | 22 +++---
arch/x86/kvm/svm/pmu.c | 8 +-
arch/x86/kvm/svm/sev.c | 4 +-
arch/x86/kvm/svm/svm.c | 50 ++++++-------
arch/x86/kvm/svm/svm.h | 4 +-
arch/x86/kvm/vmx/nested.c | 18 ++---
arch/x86/kvm/vmx/pmu_intel.c | 4 +-
arch/x86/kvm/vmx/sgx.c | 14 ++--
arch/x86/kvm/vmx/vmx.c | 63 ++++++++--------
arch/x86/kvm/vmx/vmx.h | 2 +-
arch/x86/kvm/x86.c | 72 +++++++++---------
20 files changed, 282 insertions(+), 296 deletions(-)
delete mode 100644 arch/x86/kvm/governed_features.h


base-commit: 45b890f7689eb0aba454fc5831d2d79763781677
--
2.42.0.869.gea05f2083d-goog