KVM: arm64: vgic-v3: Take cpu_if pointer directly instead of vcpu

If we move the used_lrs field to the version-specific cpu interface
structure, the following functions only operate on the struct
vgic_v3_cpu_if and not the full vcpu:

  __vgic_v3_save_state
  __vgic_v3_restore_state
  __vgic_v3_activate_traps
  __vgic_v3_deactivate_traps
  __vgic_v3_save_aprs
  __vgic_v3_restore_aprs

This is going to be very useful for nested virt, so move the used_lrs
field and change the prototypes and implementations of these functions to
take the cpu_if parameter directly.

No functional change.
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_hyp.h

@@ -56,12 +56,12 @@
 
 int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
-void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
-void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
-void __vgic_v3_activate_traps(struct kvm_vcpu *vcpu);
-void __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu);
-void __vgic_v3_save_aprs(struct kvm_vcpu *vcpu);
-void __vgic_v3_restore_aprs(struct kvm_vcpu *vcpu);
+void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_deactivate_traps(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if);
 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
 void __timer_enable_traps(struct kvm_vcpu *vcpu);

arch/arm64/kvm/hyp/switch.c

@@ -270,8 +270,8 @@ static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
 static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 {
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
-		__vgic_v3_save_state(vcpu);
-		__vgic_v3_deactivate_traps(vcpu);
+		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
+		__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 	}
 }
 
@@ -279,8 +279,8 @@ static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 static void __hyp_text __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
 {
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
-		__vgic_v3_activate_traps(vcpu);
-		__vgic_v3_restore_state(vcpu);
+		__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
+		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
 	}
 }
 

arch/arm64/kvm/hyp/vgic-v3-sr.c

@@ -194,10 +194,9 @@ static u32 __hyp_text __vgic_v3_read_ap1rn(int n)
 	return val;
 }
 
-void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 
 	/*
 	 * Make sure stores to the GIC via the memory mapped interface
@@ -230,10 +229,9 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	int i;
 
 	if (used_lrs || cpu_if->its_vpe.its_vm) {
@@ -257,10 +255,8 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_activate_traps(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	/*
 	 * VFIQEn is RES1 if ICC_SRE_EL1.SRE is 1. This causes a
 	 * Group0 interrupt (as generated in GICv2 mode) to be
@@ -306,9 +302,8 @@ void __hyp_text __vgic_v3_activate_traps(struct kvm_vcpu *vcpu)
 		write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
 }
 
-void __hyp_text __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_deactivate_traps(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
 	u64 val;
 
 	if (!cpu_if->vgic_sre) {
@@ -333,15 +328,11 @@ void __hyp_text __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu)
 		write_gicreg(0, ICH_HCR_EL2);
 }
 
-void __hyp_text __vgic_v3_save_aprs(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if;
 	u64 val;
 	u32 nr_pre_bits;
 
-	vcpu = kern_hyp_va(vcpu);
-	cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	val = read_gicreg(ICH_VTR_EL2);
 	nr_pre_bits = vtr_to_nr_pre_bits(val);
 
@@ -370,15 +361,11 @@ void __hyp_text __vgic_v3_save_aprs(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_restore_aprs(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if;
 	u64 val;
 	u32 nr_pre_bits;
 
-	vcpu = kern_hyp_va(vcpu);
-	cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	val = read_gicreg(ICH_VTR_EL2);
 	nr_pre_bits = vtr_to_nr_pre_bits(val);
 
@@ -451,7 +438,7 @@ static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu,
 						    u32 vmcr,
 						    u64 *lr_val)
 {
-	unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	unsigned int used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
 	u8 priority = GICv3_IDLE_PRIORITY;
 	int i, lr = -1;
 
@@ -490,7 +477,7 @@ static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu,
 static int __hyp_text __vgic_v3_find_active_lr(struct kvm_vcpu *vcpu,
 					       int intid, u64 *lr_val)
 {
-	unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	unsigned int used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
 	int i;
 
 	for (i = 0; i < used_lrs; i++) {

arch/arm64/kvm/vgic/vgic-v2.c

@@ -56,7 +56,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
 
 	cpuif->vgic_hcr &= ~GICH_HCR_UIE;
 
-	for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
+	for (lr = 0; lr < vgic_cpu->vgic_v2.used_lrs; lr++) {
 		u32 val = cpuif->vgic_lr[lr];
 		u32 cpuid, intid = val & GICH_LR_VIRTUALID;
 		struct vgic_irq *irq;
@@ -120,7 +120,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 
-	vgic_cpu->used_lrs = 0;
+	cpuif->used_lrs = 0;
 }
 
 /*
@@ -427,7 +427,7 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
 static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 {
 	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	u64 elrsr;
 	int i;
 
@@ -448,7 +448,7 @@ static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 void vgic_v2_save_state(struct kvm_vcpu *vcpu)
 {
 	void __iomem *base = kvm_vgic_global_state.vctrl_base;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = vcpu->arch.vgic_cpu.vgic_v2.used_lrs;
 
 	if (!base)
 		return;
@@ -463,7 +463,7 @@ void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
 {
 	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 	void __iomem *base = kvm_vgic_global_state.vctrl_base;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	int i;
 
 	if (!base)

arch/arm64/kvm/vgic/vgic-v3.c

@@ -39,7 +39,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
 
 	cpuif->vgic_hcr &= ~ICH_HCR_UIE;
 
-	for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
+	for (lr = 0; lr < cpuif->used_lrs; lr++) {
 		u64 val = cpuif->vgic_lr[lr];
 		u32 intid, cpuid;
 		struct vgic_irq *irq;
@@ -111,7 +111,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 
-	vgic_cpu->used_lrs = 0;
+	cpuif->used_lrs = 0;
 }
 
 /* Requires the irq to be locked already */
@@ -662,10 +662,10 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
 	if (likely(cpu_if->vgic_sre))
 		kvm_call_hyp(__vgic_v3_write_vmcr, cpu_if->vgic_vmcr);
 
-	kvm_call_hyp(__vgic_v3_restore_aprs, vcpu);
+	kvm_call_hyp(__vgic_v3_restore_aprs, kern_hyp_va(cpu_if));
 
 	if (has_vhe())
-		__vgic_v3_activate_traps(vcpu);
+		__vgic_v3_activate_traps(cpu_if);
 
 	WARN_ON(vgic_v4_load(vcpu));
 }
@@ -680,12 +680,14 @@ void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu)
 
 void vgic_v3_put(struct kvm_vcpu *vcpu)
 {
+	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+
 	WARN_ON(vgic_v4_put(vcpu, false));
 
 	vgic_v3_vmcr_sync(vcpu);
 
-	kvm_call_hyp(__vgic_v3_save_aprs, vcpu);
+	kvm_call_hyp(__vgic_v3_save_aprs, kern_hyp_va(cpu_if));
 
 	if (has_vhe())
-		__vgic_v3_deactivate_traps(vcpu);
+		__vgic_v3_deactivate_traps(cpu_if);
 }

arch/arm64/kvm/vgic/vgic.c

@@ -786,6 +786,7 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 	int count;
 	bool multi_sgi;
 	u8 prio = 0xff;
+	int i = 0;
 
 	lockdep_assert_held(&vgic_cpu->ap_list_lock);
 
@@ -827,11 +828,14 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 		}
 	}
 
-	vcpu->arch.vgic_cpu.used_lrs = count;
-
 	/* Nuke remaining LRs */
-	for ( ; count < kvm_vgic_global_state.nr_lr; count++)
-		vgic_clear_lr(vcpu, count);
+	for (i = count ; i < kvm_vgic_global_state.nr_lr; i++)
+		vgic_clear_lr(vcpu, i);
+
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+		vcpu->arch.vgic_cpu.vgic_v2.used_lrs = count;
+	else
+		vcpu->arch.vgic_cpu.vgic_v3.used_lrs = count;
 }
 
 static inline bool can_access_vgic_from_kernel(void)
@@ -849,13 +853,13 @@ static inline void vgic_save_state(struct kvm_vcpu *vcpu)
 	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_save_state(vcpu);
 	else
-		__vgic_v3_save_state(vcpu);
+		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
 }
 
 /* Sync back the hardware VGIC state into our emulation after a guest's run. */
 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 {
-	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	int used_lrs;
 
 	/* An empty ap_list_head implies used_lrs == 0 */
 	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
@@ -864,7 +868,12 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 	if (can_access_vgic_from_kernel())
 		vgic_save_state(vcpu);
 
-	if (vgic_cpu->used_lrs)
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+		used_lrs = vcpu->arch.vgic_cpu.vgic_v2.used_lrs;
+	else
+		used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
+
+	if (used_lrs)
 		vgic_fold_lr_state(vcpu);
 	vgic_prune_ap_list(vcpu);
 }
@@ -874,7 +883,7 @@ static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
 	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_restore_state(vcpu);
 	else
-		__vgic_v3_restore_state(vcpu);
+		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
 }
 
 /* Flush our emulation state into the GIC hardware before entering the guest. */

include/kvm/arm_vgic.h

@@ -274,6 +274,8 @@ struct vgic_v2_cpu_if {
 	u32		vgic_vmcr;
 	u32		vgic_apr;
 	u32		vgic_lr[VGIC_V2_MAX_LRS];
+
+	unsigned int used_lrs;
 };
 
 struct vgic_v3_cpu_if {
@@ -291,6 +293,8 @@ struct vgic_v3_cpu_if {
 	 * linking the Linux IRQ subsystem and the ITS together.
 	 */
 	struct its_vpe	its_vpe;
+
+	unsigned int used_lrs;
 };
 
 struct vgic_cpu {
@@ -300,7 +304,6 @@ struct vgic_cpu {
 		struct vgic_v3_cpu_if	vgic_v3;
 	};
 
-	unsigned int used_lrs;
 	struct vgic_irq private_irqs[VGIC_NR_PRIVATE_IRQS];
 
 	raw_spinlock_t ap_list_lock;	/* Protects the ap_list */