diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-11-27 17:34:17 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-12-18 14:20:15 -0800 |
| commit | 8f2a27752e808f16f3baf1939a91c42966f22a08 (patch) | |
| tree | 49b9d2fa61755ec819b70754081e43128f8e9231 /arch/x86/kvm/hyperv.c | |
| parent | 820545bdfeb0192f2afb311df9fd9d61458d89d2 (diff) | |
KVM: x86: Replace (almost) all guest CPUID feature queries with cpu_caps
Switch all queries (except XSAVES) of guest features from guest CPUID to
guest capabilities, i.e. replace all calls to guest_cpuid_has() with calls
to guest_cpu_cap_has().
Keep guest_cpuid_has() around for XSAVES, but subsume its helper
guest_cpuid_get_register() and add a compile-time assertion to prevent
using guest_cpuid_has() for any other feature. Add yet another comment
for XSAVE to explain why KVM is allowed to query its raw guest CPUID.
Opportunistically drop the unused guest_cpuid_clear(), as there should be
no circumstance in which KVM needs to _clear_ a guest CPUID feature now
that everything is tracked via cpu_caps. E.g. KVM may need to _change_
a feature to emulate dynamic CPUID flags, but KVM should never need to
clear a feature in guest CPUID to prevent it from being used by the guest.
Delete the last remnants of the governed features framework, as the lone
holdout was vmx_adjust_secondary_exec_control()'s divergent behavior for
governed vs. ungoverned features.
Note, replacing guest_cpuid_has() checks with guest_cpu_cap_has() when
computing reserved CR4 bits is a nop when viewed as a whole, as KVM's
capabilities are already incorporated into the calculation, i.e. if a
feature is present in guest CPUID but unsupported by KVM, its CR4 bit
was already being marked as reserved, checking guest_cpu_cap_has() simply
double-stamps that it's a reserved bit.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-51-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/hyperv.c')
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 4f0a94346d00..6a6dd5a84f22 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1352,7 +1352,7 @@ static void __kvm_hv_xsaves_xsavec_maybe_warn(struct kvm_vcpu *vcpu) return; if (guest_cpuid_has(vcpu, X86_FEATURE_XSAVES) || - !guest_cpuid_has(vcpu, X86_FEATURE_XSAVEC)) + !guest_cpu_cap_has(vcpu, X86_FEATURE_XSAVEC)) return; pr_notice_ratelimited("Booting SMP Windows KVM VM with !XSAVES && XSAVEC. " |