Re: [PATCH v2 3/5] KVM: x86: Use common 'enable_apicv' variable for both APICv and AVIC

[Paolo Bonzini]

On 18/05/21 22:39, Sean Christopherson wrote:
> > +/* enable / disable AVIC */
> > +static int avic;
> > +module_param(avic, int, 0444);
> We should opportunistically make avic a "bool".

And also:

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 11714c22c9f1..48cb498ff070 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -185,9 +185,12 @@ module_param(vls, int, 0444);
 static int vgif = true;
 module_param(vgif, int, 0444);
 
-/* enable / disable AVIC */
-static int avic;
-module_param(avic, int, 0444);
+/*
+ * enable / disable AVIC.  Because the defaults differ for APICv
+ * support between VMX and SVM we cannot use module_param_named.
+ */
+static bool avic;
+module_param(avic, bool, 0444);
 
 bool __read_mostly dump_invalid_vmcb;
 module_param(dump_invalid_vmcb, bool, 0644);
@@ -1013,11 +1016,7 @@ static __init int svm_hardware_setup(void)
 			nrips = false;
 	}
 
-	if (!npt_enabled || !boot_cpu_has(X86_FEATURE_AVIC))
-		avic = false;
-
-	/* 'enable_apicv' is common between VMX/SVM but the defaults differ */
-	enable_apicv = avic;
+	enable_apicv = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC);
 	if (enable_apicv) {
 		pr_info("AVIC enabled\n");
 

The "if" can come back when AVIC is enabled by default.

Paolo