[patch 4/4] kvm-s390: implement sigp external call

[Christian Borntraeger <borntraeger@de.ibm.com>]

[-- Attachment #1: 503-kvm-external-call.diff --]
[-- Type: text/plain, Size: 7668 bytes --]

From: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>

Implement sigp external call, which might be required for guests that
issue an external call instead of an emergency signal for IPI.

This fixes an issue with "KVM: unknown SIGP: 0x02" when booting
such an SMP guest.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---

 arch/s390/include/asm/kvm_host.h |    7 ++++++
 arch/s390/kvm/interrupt.c        |   30 ++++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.c         |    2 +
 arch/s390/kvm/sigp.c             |   45 ++++++++++++++++++++++++++++++++++++++-
 include/linux/kvm.h              |    1 
 5 files changed, 84 insertions(+), 1 deletion(-)

Index: b/arch/s390/include/asm/kvm_host.h
===================================================================
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -119,6 +119,7 @@ struct kvm_vcpu_stat {
 	u32 instruction_lctlg;
 	u32 exit_program_interruption;
 	u32 exit_instr_and_program;
+	u32 deliver_external_call;
 	u32 deliver_emergency_signal;
 	u32 deliver_service_signal;
 	u32 deliver_virtio_interrupt;
@@ -138,6 +139,7 @@ struct kvm_vcpu_stat {
 	u32 instruction_stfl;
 	u32 instruction_tprot;
 	u32 instruction_sigp_sense;
+	u32 instruction_sigp_external_call;
 	u32 instruction_sigp_emergency;
 	u32 instruction_sigp_stop;
 	u32 instruction_sigp_arch;
@@ -174,6 +176,10 @@ struct kvm_s390_prefix_info {
 	__u32 address;
 };
 
+struct kvm_s390_extcall_info {
+	__u16 code;
+};
+
 struct kvm_s390_emerg_info {
 	__u16 code;
 };
@@ -186,6 +192,7 @@ struct kvm_s390_interrupt_info {
 		struct kvm_s390_ext_info ext;
 		struct kvm_s390_pgm_info pgm;
 		struct kvm_s390_emerg_info emerg;
+		struct kvm_s390_extcall_info extcall;
 		struct kvm_s390_prefix_info prefix;
 	};
 };
Index: b/arch/s390/kvm/interrupt.c
===================================================================
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -38,6 +38,11 @@ static int __interrupt_is_deliverable(st
 				      struct kvm_s390_interrupt_info *inti)
 {
 	switch (inti->type) {
+	case KVM_S390_INT_EXTERNAL_CALL:
+		if (psw_extint_disabled(vcpu))
+			return 0;
+		if (vcpu->arch.sie_block->gcr[0] & 0x2000ul)
+			return 1;
 	case KVM_S390_INT_EMERGENCY:
 		if (psw_extint_disabled(vcpu))
 			return 0;
@@ -98,6 +103,7 @@ static void __set_intercept_indicator(st
 				      struct kvm_s390_interrupt_info *inti)
 {
 	switch (inti->type) {
+	case KVM_S390_INT_EXTERNAL_CALL:
 	case KVM_S390_INT_EMERGENCY:
 	case KVM_S390_INT_SERVICE:
 	case KVM_S390_INT_VIRTIO:
@@ -143,6 +149,28 @@ static void __do_deliver_interrupt(struc
 			exception = 1;
 		break;
 
+	case KVM_S390_INT_EXTERNAL_CALL:
+		VCPU_EVENT(vcpu, 4, "%s", "interrupt: sigp ext call");
+		vcpu->stat.deliver_external_call++;
+		rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1202);
+		if (rc == -EFAULT)
+			exception = 1;
+
+		rc = put_guest_u16(vcpu, __LC_CPU_ADDRESS, inti->extcall.code);
+		if (rc == -EFAULT)
+			exception = 1;
+
+		rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
+			 &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
+		if (rc == -EFAULT)
+			exception = 1;
+
+		rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
+			__LC_EXT_NEW_PSW, sizeof(psw_t));
+		if (rc == -EFAULT)
+			exception = 1;
+		break;
+
 	case KVM_S390_INT_SERVICE:
 		VCPU_EVENT(vcpu, 4, "interrupt: sclp parm:%x",
 			   inti->ext.ext_params);
@@ -522,6 +550,7 @@ int kvm_s390_inject_vm(struct kvm *kvm,
 		break;
 	case KVM_S390_PROGRAM_INT:
 	case KVM_S390_SIGP_STOP:
+	case KVM_S390_INT_EXTERNAL_CALL:
 	case KVM_S390_INT_EMERGENCY:
 	default:
 		kfree(inti);
@@ -581,6 +610,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu
 		break;
 	case KVM_S390_SIGP_STOP:
 	case KVM_S390_RESTART:
+	case KVM_S390_INT_EXTERNAL_CALL:
 	case KVM_S390_INT_EMERGENCY:
 		VCPU_EVENT(vcpu, 3, "inject: type %x", s390int->type);
 		inti->type = s390int->type;
Index: b/arch/s390/kvm/kvm-s390.c
===================================================================
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -46,6 +46,7 @@ struct kvm_stats_debugfs_item debugfs_en
 	{ "instruction_lctlg", VCPU_STAT(instruction_lctlg) },
 	{ "instruction_lctl", VCPU_STAT(instruction_lctl) },
 	{ "deliver_emergency_signal", VCPU_STAT(deliver_emergency_signal) },
+	{ "deliver_external_call", VCPU_STAT(deliver_external_call) },
 	{ "deliver_service_signal", VCPU_STAT(deliver_service_signal) },
 	{ "deliver_virtio_interrupt", VCPU_STAT(deliver_virtio_interrupt) },
 	{ "deliver_stop_signal", VCPU_STAT(deliver_stop_signal) },
@@ -64,6 +65,7 @@ struct kvm_stats_debugfs_item debugfs_en
 	{ "instruction_stfl", VCPU_STAT(instruction_stfl) },
 	{ "instruction_tprot", VCPU_STAT(instruction_tprot) },
 	{ "instruction_sigp_sense", VCPU_STAT(instruction_sigp_sense) },
+	{ "instruction_sigp_external_call", VCPU_STAT(instruction_sigp_external_call) },
 	{ "instruction_sigp_emergency", VCPU_STAT(instruction_sigp_emergency) },
 	{ "instruction_sigp_stop", VCPU_STAT(instruction_sigp_stop) },
 	{ "instruction_sigp_set_arch", VCPU_STAT(instruction_sigp_arch) },
Index: b/arch/s390/kvm/sigp.c
===================================================================
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -87,6 +87,7 @@ static int __sigp_emergency(struct kvm_v
 		return -ENOMEM;
 
 	inti->type = KVM_S390_INT_EMERGENCY;
+	inti->emerg.code = vcpu->vcpu_id;
 
 	spin_lock(&fi->lock);
 	li = fi->local_int[cpu_addr];
@@ -103,9 +104,47 @@ static int __sigp_emergency(struct kvm_v
 		wake_up_interruptible(&li->wq);
 	spin_unlock_bh(&li->lock);
 	rc = 0; /* order accepted */
+	VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
+unlock:
+	spin_unlock(&fi->lock);
+	return rc;
+}
+
+static int __sigp_external_call(struct kvm_vcpu *vcpu, u16 cpu_addr)
+{
+	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
+	struct kvm_s390_local_interrupt *li;
+	struct kvm_s390_interrupt_info *inti;
+	int rc;
+
+	if (cpu_addr >= KVM_MAX_VCPUS)
+		return 3; /* not operational */
+
+	inti = kzalloc(sizeof(*inti), GFP_KERNEL);
+	if (!inti)
+		return -ENOMEM;
+
+	inti->type = KVM_S390_INT_EXTERNAL_CALL;
+	inti->extcall.code = vcpu->vcpu_id;
+
+	spin_lock(&fi->lock);
+	li = fi->local_int[cpu_addr];
+	if (li == NULL) {
+		rc = 3; /* not operational */
+		kfree(inti);
+		goto unlock;
+	}
+	spin_lock_bh(&li->lock);
+	list_add_tail(&inti->list, &li->list);
+	atomic_set(&li->active, 1);
+	atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
+	if (waitqueue_active(&li->wq))
+		wake_up_interruptible(&li->wq);
+	spin_unlock_bh(&li->lock);
+	rc = 0; /* order accepted */
+	VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x", cpu_addr);
 unlock:
 	spin_unlock(&fi->lock);
-	VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
 	return rc;
 }
 
@@ -267,6 +306,10 @@ int kvm_s390_handle_sigp(struct kvm_vcpu
 		rc = __sigp_sense(vcpu, cpu_addr,
 				  &vcpu->arch.guest_gprs[r1]);
 		break;
+	case SIGP_EXTERNAL_CALL:
+		vcpu->stat.instruction_sigp_external_call++;
+		rc = __sigp_external_call(vcpu, cpu_addr);
+		break;
 	case SIGP_EMERGENCY:
 		vcpu->stat.instruction_sigp_emergency++;
 		rc = __sigp_emergency(vcpu, cpu_addr);
Index: b/include/linux/kvm.h
===================================================================
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -371,6 +371,7 @@ struct kvm_s390_psw {
 #define KVM_S390_INT_VIRTIO		0xffff2603u
 #define KVM_S390_INT_SERVICE		0xffff2401u
 #define KVM_S390_INT_EMERGENCY		0xffff1201u
+#define KVM_S390_INT_EXTERNAL_CALL	0xffff1202u
 
 struct kvm_s390_interrupt {
 	__u32 type;