KVM/ARM Changes for v4.14

Two minor cleanups and improvements, a fix for decoding external abort
 types from guests, and added support for migrating the active priority
 of interrupts when running a GICv2 guest on a GICv3 host.
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Merge tag 'kvm-arm-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

KVM/ARM Changes for v4.14

Two minor cleanups and improvements, a fix for decoding external abort
types from guests, and added support for migrating the active priority
of interrupts when running a GICv2 guest on a GICv3 host.

Documentation/virtual/kvm/devices/arm-vgic.txt

@@ -83,6 +83,11 @@ Groups:
 
     Bits for undefined preemption levels are RAZ/WI.
 
+    Note that this differs from a CPU's view of the APRs on hardware in which
+    a GIC without the security extensions expose group 0 and group 1 active
+    priorities in separate register groups, whereas we show a combined view
+    similar to GICv2's GICH_APR.
+
     For historical reasons and to provide ABI compatibility with userspace we
     export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask
     field in the lower 5 bits of a word, meaning that userspace must always

arch/arm/include/asm/kvm_arm.h

@@ -227,7 +227,6 @@
 
 #define HSR_DABT_S1PTW		(_AC(1, UL) << 7)
 #define HSR_DABT_CM		(_AC(1, UL) << 8)
-#define HSR_DABT_EA		(_AC(1, UL) << 9)
 
 #define kvm_arm_exception_type	\
 	{0, "RESET" }, 		\

arch/arm/include/asm/kvm_emulate.h

@@ -149,11 +149,6 @@ static inline int kvm_vcpu_dabt_get_rd(struct kvm_vcpu *vcpu)
 	return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
 }
 
-static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
-{
-	return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_EA;
-}
-
 static inline bool kvm_vcpu_dabt_iss1tw(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_S1PTW;
@@ -206,6 +201,25 @@ static inline u8 kvm_vcpu_trap_get_fault_type(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_get_hsr(vcpu) & HSR_FSC_TYPE;
 }
 
+static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
+{
+	switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
+	case FSC_SEA:
+	case FSC_SEA_TTW0:
+	case FSC_SEA_TTW1:
+	case FSC_SEA_TTW2:
+	case FSC_SEA_TTW3:
+	case FSC_SECC:
+	case FSC_SECC_TTW0:
+	case FSC_SECC_TTW1:
+	case FSC_SECC_TTW2:
+	case FSC_SECC_TTW3:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK;

arch/arm64/include/asm/kvm_emulate.h

@@ -188,11 +188,6 @@ static inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
 	return (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
 }
 
-static inline bool kvm_vcpu_dabt_isextabt(const struct kvm_vcpu *vcpu)
-{
-	return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_EA);
-}
-
 static inline bool kvm_vcpu_dabt_iss1tw(const struct kvm_vcpu *vcpu)
 {
 	return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_S1PTW);
@@ -240,6 +235,25 @@ static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
 	return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC_TYPE;
 }
 
+static inline bool kvm_vcpu_dabt_isextabt(const struct kvm_vcpu *vcpu)
+{
+	switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
+	case FSC_SEA:
+	case FSC_SEA_TTW0:
+	case FSC_SEA_TTW1:
+	case FSC_SEA_TTW2:
+	case FSC_SEA_TTW3:
+	case FSC_SECC:
+	case FSC_SECC_TTW0:
+	case FSC_SECC_TTW1:
+	case FSC_SECC_TTW2:
+	case FSC_SECC_TTW3:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
 {
 	u32 esr = kvm_vcpu_get_hsr(vcpu);

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

@@ -208,29 +208,12 @@ static void vgic_v3_access_apr_reg(struct kvm_vcpu *vcpu,
 static bool access_gic_aprn(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			    const struct sys_reg_desc *r, u8 apr)
 {
-	struct vgic_cpu *vgic_v3_cpu = &vcpu->arch.vgic_cpu;
 	u8 idx = r->Op2 & 3;
 
-	/*
+	if (idx > vgic_v3_max_apr_idx(vcpu))
-	 * num_pri_bits are initialized with HW supported values.
+		goto err;
-	 * We can rely safely on num_pri_bits even if VM has not
-	 * restored ICC_CTLR_EL1 before restoring APnR registers.
-	 */
-	switch (vgic_v3_cpu->num_pri_bits) {
-	case 7:
-		vgic_v3_access_apr_reg(vcpu, p, apr, idx);
-		break;
-	case 6:
-		if (idx > 1)
-			goto err;
-		vgic_v3_access_apr_reg(vcpu, p, apr, idx);
-		break;
-	default:
-		if (idx > 0)
-			goto err;
-		vgic_v3_access_apr_reg(vcpu, p, apr, idx);
-	}
 
+	vgic_v3_access_apr_reg(vcpu, p, apr, idx);
 	return true;
 err:
 	if (!p->is_write)

virt/kvm/arm/mmu.c

@@ -1454,25 +1454,6 @@ out:
 		kvm_set_pfn_accessed(pfn);
 }
 
-static bool is_abort_sea(unsigned long fault_status)
-{
-	switch (fault_status) {
-	case FSC_SEA:
-	case FSC_SEA_TTW0:
-	case FSC_SEA_TTW1:
-	case FSC_SEA_TTW2:
-	case FSC_SEA_TTW3:
-	case FSC_SECC:
-	case FSC_SECC_TTW0:
-	case FSC_SECC_TTW1:
-	case FSC_SECC_TTW2:
-	case FSC_SECC_TTW3:
-		return true;
-	default:
-		return false;
-	}
-}
-
 /**
  * kvm_handle_guest_abort - handles all 2nd stage aborts
  * @vcpu:	the VCPU pointer
@@ -1498,20 +1479,21 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
 
 	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
 
-	/*
+	/* Synchronous External Abort? */
-	 * The host kernel will handle the synchronous external abort. There
+	if (kvm_vcpu_dabt_isextabt(vcpu)) {
-	 * is no need to pass the error into the guest.
+		/*
-	 */
+		 * For RAS the host kernel may handle this abort.
-	if (is_abort_sea(fault_status)) {
+		 * There is no need to pass the error into the guest.
+		 */
 		if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu)))
 			return 1;
-	}
 
-	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
+		if (unlikely(!is_iabt)) {
-	if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
+			kvm_inject_vabt(vcpu);
-		kvm_inject_vabt(vcpu);
+			return 1;
-		return 1;
+		}
 	}
 
 	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),

virt/kvm/arm/vgic/vgic-debug.c

@@ -234,7 +234,7 @@ static int vgic_debug_show(struct seq_file *s, void *v)
 	return 0;
 }
 
-static struct seq_operations vgic_debug_seq_ops = {
+static const struct seq_operations vgic_debug_seq_ops = {
 	.start = vgic_debug_start,
 	.next  = vgic_debug_next,
 	.stop  = vgic_debug_stop,
@@ -255,7 +255,7 @@ static int debug_open(struct inode *inode, struct file *file)
 	return ret;
 };
 
-static struct file_operations vgic_debug_fops = {
+static const struct file_operations vgic_debug_fops = {
 	.owner   = THIS_MODULE,
 	.open    = debug_open,
 	.read    = seq_read,

virt/kvm/arm/vgic/vgic-its.c

@@ -144,7 +144,6 @@ struct its_ite {
 
 	struct vgic_irq *irq;
 	struct its_collection *collection;
-	u32 lpi;
 	u32 event_id;
 };
 
@@ -813,7 +812,7 @@ static void vgic_its_free_collection(struct vgic_its *its, u32 coll_id)
 /* Must be called with its_lock mutex held */
 static struct its_ite *vgic_its_alloc_ite(struct its_device *device,
 					  struct its_collection *collection,
-					  u32 lpi_id, u32 event_id)
+					  u32 event_id)
 {
 	struct its_ite *ite;
 
@@ -823,7 +822,6 @@ static struct its_ite *vgic_its_alloc_ite(struct its_device *device,
 
 	ite->event_id	= event_id;
 	ite->collection = collection;
-	ite->lpi = lpi_id;
 
 	list_add_tail(&ite->ite_list, &device->itt_head);
 	return ite;
@@ -873,7 +871,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 		new_coll = collection;
 	}
 
-	ite = vgic_its_alloc_ite(device, collection, lpi_nr, event_id);
+	ite = vgic_its_alloc_ite(device, collection, event_id);
 	if (IS_ERR(ite)) {
 		if (new_coll)
 			vgic_its_free_collection(its, coll_id);
@@ -1848,7 +1846,7 @@ static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev,
 
 	next_offset = compute_next_eventid_offset(&dev->itt_head, ite);
 	val = ((u64)next_offset << KVM_ITS_ITE_NEXT_SHIFT) |
-	       ((u64)ite->lpi << KVM_ITS_ITE_PINTID_SHIFT) |
+	       ((u64)ite->irq->intid << KVM_ITS_ITE_PINTID_SHIFT) |
 		ite->collection->collection_id;
 	val = cpu_to_le64(val);
 	return kvm_write_guest(kvm, gpa, &val, ite_esz);
@@ -1895,7 +1893,7 @@ static int vgic_its_restore_ite(struct vgic_its *its, u32 event_id,
 	if (!collection)
 		return -EINVAL;
 
-	ite = vgic_its_alloc_ite(dev, collection, lpi_id, event_id);
+	ite = vgic_its_alloc_ite(dev, collection, event_id);
 	if (IS_ERR(ite))
 		return PTR_ERR(ite);
 

virt/kvm/arm/vgic/vgic-mmio-v2.c

@@ -303,6 +303,51 @@ static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
 	vgic_set_vmcr(vcpu, &vmcr);
 }
 
+static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
+					gpa_t addr, unsigned int len)
+{
+	int n; /* which APRn is this */
+
+	n = (addr >> 2) & 0x3;
+
+	if (kvm_vgic_global_state.type == VGIC_V2) {
+		/* GICv2 hardware systems support max. 32 groups */
+		if (n != 0)
+			return 0;
+		return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
+	} else {
+		struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
+
+		if (n > vgic_v3_max_apr_idx(vcpu))
+			return 0;
+		/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
+		return vgicv3->vgic_ap1r[n];
+	}
+}
+
+static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
+				gpa_t addr, unsigned int len,
+				unsigned long val)
+{
+	int n; /* which APRn is this */
+
+	n = (addr >> 2) & 0x3;
+
+	if (kvm_vgic_global_state.type == VGIC_V2) {
+		/* GICv2 hardware systems support max. 32 groups */
+		if (n != 0)
+			return;
+		vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
+	} else {
+		struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
+
+		if (n > vgic_v3_max_apr_idx(vcpu))
+			return;
+		/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
+		vgicv3->vgic_ap1r[n] = val;
+	}
+}
+
 static const struct vgic_register_region vgic_v2_dist_registers[] = {
 	REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
 		vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12,
@@ -364,7 +409,7 @@ static const struct vgic_register_region vgic_v2_cpu_registers[] = {
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 16,
+		vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
 		vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,

virt/kvm/arm/vgic/vgic.h

@@ -220,4 +220,20 @@ int vgic_debug_destroy(struct kvm *kvm);
 bool lock_all_vcpus(struct kvm *kvm);
 void unlock_all_vcpus(struct kvm *kvm);
 
+static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *cpu_if = &vcpu->arch.vgic_cpu;
+
+	/*
+	 * num_pri_bits are initialized with HW supported values.
+	 * We can rely safely on num_pri_bits even if VM has not
+	 * restored ICC_CTLR_EL1 before restoring APnR registers.
+	 */
+	switch (cpu_if->num_pri_bits) {
+	case 7: return 3;
+	case 6: return 1;
+	default: return 0;
+	}
+}
+
 #endif