KVM: x86: Rename "governed features" helpers to use "guest_cpu_cap"

As the first step toward replacing KVM's so-called "governed features"
framework with a more comprehensive, less poorly named implementation,
replace the "kvm_governed_feature" function prefix with "guest_cpu_cap"
and rename guest_can_use() to guest_cpu_cap_has().

The "guest_cpu_cap" naming scheme mirrors that of "kvm_cpu_cap", and
provides a more clear distinction between guest capabilities, which are
KVM controlled (heh, or one might say "governed"), and guest CPUID, which
with few exceptions is fully userspace controlled.

Opportunistically rewrite the comment about XSS passthrough for SEV-ES
guests to avoid referencing so many functions, as such comments are prone
to becoming stale (case in point...).

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-40-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 11 insertions, 11 deletions

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index b708bdf7eaff..d77b094d9a4d 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -111,7 +111,7 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
 
 static bool nested_vmcb_needs_vls_intercept(struct vcpu_svm *svm)
 {
-	if (!guest_can_use(&svm->vcpu, X86_FEATURE_V_VMSAVE_VMLOAD))
+	if (!guest_cpu_cap_has(&svm->vcpu, X86_FEATURE_V_VMSAVE_VMLOAD))
 		return true;
 
 	if (!nested_npt_enabled(svm))
@@ -594,7 +594,7 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
 		vmcb_mark_dirty(vmcb02, VMCB_DR);
 	}
 
-	if (unlikely(guest_can_use(vcpu, X86_FEATURE_LBRV) &&
+	if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
 		     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
 		/*
 		 * Reserved bits of DEBUGCTL are ignored.  Be consistent with
@@ -651,7 +651,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 	 * exit_int_info, exit_int_info_err, next_rip, insn_len, insn_bytes.
 	 */
 
-	if (guest_can_use(vcpu, X86_FEATURE_VGIF) &&
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_VGIF) &&
 	    (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
 		int_ctl_vmcb12_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
 	else
@@ -689,7 +689,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 
 	vmcb02->control.tsc_offset = vcpu->arch.tsc_offset;
 
-	if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) &&
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_TSCRATEMSR) &&
 	    svm->tsc_ratio_msr != kvm_caps.default_tsc_scaling_ratio)
 		nested_svm_update_tsc_ratio_msr(vcpu);
 
@@ -710,7 +710,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 	 * what a nrips=0 CPU would do (L1 is responsible for advancing RIP
 	 * prior to injecting the event).
 	 */
-	if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
 		vmcb02->control.next_rip    = svm->nested.ctl.next_rip;
 	else if (boot_cpu_has(X86_FEATURE_NRIPS))
 		vmcb02->control.next_rip    = vmcb12_rip;
@@ -720,7 +720,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 		svm->soft_int_injected = true;
 		svm->soft_int_csbase = vmcb12_csbase;
 		svm->soft_int_old_rip = vmcb12_rip;
-		if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
+		if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
 			svm->soft_int_next_rip = svm->nested.ctl.next_rip;
 		else
 			svm->soft_int_next_rip = vmcb12_rip;
@@ -728,18 +728,18 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 
 	vmcb02->control.virt_ext            = vmcb01->control.virt_ext &
 					      LBR_CTL_ENABLE_MASK;
-	if (guest_can_use(vcpu, X86_FEATURE_LBRV))
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV))
 		vmcb02->control.virt_ext  |=
 			(svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK);
 
 	if (!nested_vmcb_needs_vls_intercept(svm))
 		vmcb02->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK;
 
-	if (guest_can_use(vcpu, X86_FEATURE_PAUSEFILTER))
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_PAUSEFILTER))
 		pause_count12 = svm->nested.ctl.pause_filter_count;
 	else
 		pause_count12 = 0;
-	if (guest_can_use(vcpu, X86_FEATURE_PFTHRESHOLD))
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_PFTHRESHOLD))
 		pause_thresh12 = svm->nested.ctl.pause_filter_thresh;
 	else
 		pause_thresh12 = 0;
@@ -1026,7 +1026,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	if (vmcb12->control.exit_code != SVM_EXIT_ERR)
 		nested_save_pending_event_to_vmcb12(svm, vmcb12);
 
-	if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
 		vmcb12->control.next_rip  = vmcb02->control.next_rip;
 
 	vmcb12->control.int_ctl           = svm->nested.ctl.int_ctl;
@@ -1065,7 +1065,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	if (!nested_exit_on_intr(svm))
 		kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
 
-	if (unlikely(guest_can_use(vcpu, X86_FEATURE_LBRV) &&
+	if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
 		     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
 		svm_copy_lbrs(vmcb12, vmcb02);
 		svm_update_lbrv(vcpu);