KVM: x86: Use common 'enable_apicv' variable for both APICv and AVIC

Unify VMX and SVM code by moving APICv/AVIC enablement tracking to common
'enable_apicv' variable. Note: unlike APICv, AVIC is disabled by default.

No functional change intended.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210609150911.1471882c-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1432,6 +1432,7 @@ struct kvm_arch_async_pf {
 extern u32 __read_mostly kvm_nr_uret_msrs;
 extern u64 __read_mostly host_efer;
 extern bool __read_mostly allow_smaller_maxphyaddr;
+extern bool __read_mostly enable_apicv;
 extern struct kvm_x86_ops kvm_x86_ops;
 
 #define KVM_X86_OP(func) \

arch/x86/kvm/svm/avic.c

@@ -27,10 +27,6 @@
 #include "irq.h"
 #include "svm.h"
 
-/* enable / disable AVIC */
-bool avic;
-module_param(avic, bool, S_IRUGO);
-
 #define SVM_AVIC_DOORBELL	0xc001011b
 
 #define AVIC_HPA_MASK	~((0xFFFULL << 52) | 0xFFF)
@@ -124,7 +120,7 @@ void avic_vm_destroy(struct kvm *kvm)
 	unsigned long flags;
 	struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
 
-	if (!avic)
+	if (!enable_apicv)
 		return;
 
 	if (kvm_svm->avic_logical_id_table_page)
@@ -147,7 +143,7 @@ int avic_vm_init(struct kvm *kvm)
 	struct page *l_page;
 	u32 vm_id;
 
-	if (!avic)
+	if (!enable_apicv)
 		return 0;
 
 	/* Allocating physical APIC ID table (4KB) */
@@ -569,7 +565,7 @@ int avic_init_vcpu(struct vcpu_svm *svm)
 	int ret;
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 
-	if (!avic || !irqchip_in_kernel(vcpu->kvm))
+	if (!enable_apicv || !irqchip_in_kernel(vcpu->kvm))
 		return 0;
 
 	ret = avic_init_backing_page(vcpu);
@@ -593,7 +589,7 @@ void avic_post_state_restore(struct kvm_vcpu *vcpu)
 
 void svm_toggle_avic_for_irq_window(struct kvm_vcpu *vcpu, bool activate)
 {
-	if (!avic || !lapic_in_kernel(vcpu))
+	if (!enable_apicv || !lapic_in_kernel(vcpu))
 		return;
 
 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
@@ -653,7 +649,7 @@ void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
 	struct vmcb *vmcb = svm->vmcb;
 	bool activated = kvm_vcpu_apicv_active(vcpu);
 
-	if (!avic)
+	if (!enable_apicv)
 		return;
 
 	if (activated) {

arch/x86/kvm/svm/svm.c

@@ -185,6 +185,13 @@ module_param(vls, int, 0444);
 static int vgif = true;
 module_param(vgif, 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);
 
@@ -1009,15 +1016,13 @@ static __init int svm_hardware_setup(void)
 			nrips = false;
 	}
 
-	if (avic) {
-		if (!npt_enabled || !boot_cpu_has(X86_FEATURE_AVIC)) {
-			avic = false;
-		} else {
+	enable_apicv = avic = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC);
+
+	if (enable_apicv) {
 		pr_info("AVIC enabled\n");
 
 		amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
 	}
-	}
 
 	if (vls) {
 		if (!npt_enabled ||
@@ -4431,13 +4436,13 @@ static int svm_vm_init(struct kvm *kvm)
 	if (!pause_filter_count || !pause_filter_thresh)
 		kvm->arch.pause_in_guest = true;
 
-	if (avic) {
+	if (enable_apicv) {
 		int ret = avic_vm_init(kvm);
 		if (ret)
 			return ret;
 	}
 
-	kvm_apicv_init(kvm, avic);
+	kvm_apicv_init(kvm, enable_apicv);
 	return 0;
 }
 

arch/x86/kvm/svm/svm.h

@@ -479,8 +479,6 @@ extern struct kvm_x86_nested_ops svm_nested_ops;
 
 #define VMCB_AVIC_APIC_BAR_MASK		0xFFFFFFFFFF000ULL
 
-extern bool avic;
-
 static inline void avic_update_vapic_bar(struct vcpu_svm *svm, u64 data)
 {
 	svm->vmcb->control.avic_vapic_bar = data & VMCB_AVIC_APIC_BAR_MASK;

arch/x86/kvm/vmx/capabilities.h

@@ -12,7 +12,6 @@ extern bool __read_mostly enable_ept;
 extern bool __read_mostly enable_unrestricted_guest;
 extern bool __read_mostly enable_ept_ad_bits;
 extern bool __read_mostly enable_pml;
-extern bool __read_mostly enable_apicv;
 extern int __read_mostly pt_mode;
 
 #define PT_MODE_SYSTEM		0

arch/x86/kvm/vmx/vmx.c

@@ -101,7 +101,6 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO);
 static bool __read_mostly fasteoi = 1;
 module_param(fasteoi, bool, S_IRUGO);
 
-bool __read_mostly enable_apicv = 1;
 module_param(enable_apicv, bool, S_IRUGO);
 
 /*

arch/x86/kvm/x86.c

@@ -210,6 +210,9 @@ EXPORT_SYMBOL_GPL(host_efer);
 bool __read_mostly allow_smaller_maxphyaddr = 0;
 EXPORT_SYMBOL_GPL(allow_smaller_maxphyaddr);
 
+bool __read_mostly enable_apicv = true;
+EXPORT_SYMBOL_GPL(enable_apicv);
+
 u64 __read_mostly host_xss;
 EXPORT_SYMBOL_GPL(host_xss);
 u64 __read_mostly supported_xss;