KVM: s390: protvirt: Report CPU state to Ultravisor

VCPU states have to be reported to the ultravisor for SIGP
interpretation, kdump, kexec and reboot.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/uv.h

@@ -37,6 +37,7 @@
 #define UVC_CMD_UNPACK_IMG		0x0301
 #define UVC_CMD_VERIFY_IMG		0x0302
 #define UVC_CMD_PREPARE_RESET		0x0320
+#define UVC_CMD_CPU_SET_STATE		0x0330
 #define UVC_CMD_SET_UNSHARE_ALL		0x0340
 #define UVC_CMD_PIN_PAGE_SHARED		0x0341
 #define UVC_CMD_UNPIN_PAGE_SHARED	0x0342
@@ -58,6 +59,7 @@ enum uv_cmds_inst {
 	BIT_UVC_CMD_SET_SEC_PARMS = 11,
 	BIT_UVC_CMD_UNPACK_IMG = 13,
 	BIT_UVC_CMD_VERIFY_IMG = 14,
+	BIT_UVC_CMD_CPU_SET_STATE = 17,
 	BIT_UVC_CMD_PREPARE_RESET = 18,
 	BIT_UVC_CMD_UNSHARE_ALL = 20,
 	BIT_UVC_CMD_PIN_PAGE_SHARED = 21,
@@ -164,6 +166,19 @@ struct uv_cb_unp {
 	u64 reserved38[3];
 } __packed __aligned(8);
 
+#define PV_CPU_STATE_OPR	1
+#define PV_CPU_STATE_STP	2
+#define PV_CPU_STATE_CHKSTP	3
+
+struct uv_cb_cpu_set_state {
+	struct uv_cb_header header;
+	u64 reserved08[2];
+	u64 cpu_handle;
+	u8  reserved20[7];
+	u8  state;
+	u64 reserved28[5];
+};
+
 /*
  * A common UV call struct for calls that take no payload
  * Examples:

arch/s390/kvm/diag.c

@@ -2,7 +2,7 @@
 /*
  * handling diagnose instructions
  *
- * Copyright IBM Corp. 2008, 2011
+ * Copyright IBM Corp. 2008, 2020
  *
  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  *               Christian Borntraeger <borntraeger@de.ibm.com>
@@ -201,6 +201,10 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
 		return -EOPNOTSUPP;
 	}
 
+	/*
+	 * no need to check the return value of vcpu_stop as it can only have
+	 * an error for protvirt, but protvirt means user cpu state
+	 */
 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
 		kvm_s390_vcpu_stop(vcpu);
 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;

arch/s390/kvm/intercept.c

@@ -80,6 +80,10 @@ static int handle_stop(struct kvm_vcpu *vcpu)
 			return rc;
 	}
 
+	/*
+	 * no need to check the return value of vcpu_stop as it can only have
+	 * an error for protvirt, but protvirt means user cpu state
+	 */
 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
 		kvm_s390_vcpu_stop(vcpu);
 	return -EOPNOTSUPP;

arch/s390/kvm/kvm-s390.c

@@ -2456,6 +2456,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	case KVM_S390_PV_COMMAND: {
 		struct kvm_pv_cmd args;
 
+		/* protvirt means user sigp */
+		kvm->arch.user_cpu_state_ctrl = 1;
 		r = 0;
 		if (!is_prot_virt_host()) {
 			r = -EINVAL;
@@ -3728,10 +3730,10 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 
 	switch (mp_state->mp_state) {
 	case KVM_MP_STATE_STOPPED:
-		kvm_s390_vcpu_stop(vcpu);
+		rc = kvm_s390_vcpu_stop(vcpu);
 		break;
 	case KVM_MP_STATE_OPERATING:
-		kvm_s390_vcpu_start(vcpu);
+		rc = kvm_s390_vcpu_start(vcpu);
 		break;
 	case KVM_MP_STATE_LOAD:
 	case KVM_MP_STATE_CHECK_STOP:
@@ -4316,6 +4318,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
 	kvm_sigset_activate(vcpu);
 
+	/*
+	 * no need to check the return value of vcpu_start as it can only have
+	 * an error for protvirt, but protvirt means user cpu state
+	 */
 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) {
 		kvm_s390_vcpu_start(vcpu);
 	} else if (is_vcpu_stopped(vcpu)) {
@@ -4453,18 +4459,27 @@ static void __enable_ibs_on_vcpu(struct kvm_vcpu *vcpu)
 	kvm_s390_sync_request(KVM_REQ_ENABLE_IBS, vcpu);
 }
 
-void kvm_s390_vcpu_start(struct kvm_vcpu *vcpu)
+int kvm_s390_vcpu_start(struct kvm_vcpu *vcpu)
 {
-	int i, online_vcpus, started_vcpus = 0;
+	int i, online_vcpus, r = 0, started_vcpus = 0;
 
 	if (!is_vcpu_stopped(vcpu))
-		return;
+		return 0;
 
 	trace_kvm_s390_vcpu_start_stop(vcpu->vcpu_id, 1);
 	/* Only one cpu at a time may enter/leave the STOPPED state. */
 	spin_lock(&vcpu->kvm->arch.start_stop_lock);
 	online_vcpus = atomic_read(&vcpu->kvm->online_vcpus);
 
+	/* Let's tell the UV that we want to change into the operating state */
+	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+		r = kvm_s390_pv_set_cpu_state(vcpu, PV_CPU_STATE_OPR);
+		if (r) {
+			spin_unlock(&vcpu->kvm->arch.start_stop_lock);
+			return r;
+		}
+	}
+
 	for (i = 0; i < online_vcpus; i++) {
 		if (!is_vcpu_stopped(vcpu->kvm->vcpus[i]))
 			started_vcpus++;
@@ -4489,22 +4504,31 @@ void kvm_s390_vcpu_start(struct kvm_vcpu *vcpu)
 	 */
 	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	spin_unlock(&vcpu->kvm->arch.start_stop_lock);
-	return;
+	return 0;
 }
 
-void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
+int kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
 {
-	int i, online_vcpus, started_vcpus = 0;
+	int i, online_vcpus, r = 0, started_vcpus = 0;
 	struct kvm_vcpu *started_vcpu = NULL;
 
 	if (is_vcpu_stopped(vcpu))
-		return;
+		return 0;
 
 	trace_kvm_s390_vcpu_start_stop(vcpu->vcpu_id, 0);
 	/* Only one cpu at a time may enter/leave the STOPPED state. */
 	spin_lock(&vcpu->kvm->arch.start_stop_lock);
 	online_vcpus = atomic_read(&vcpu->kvm->online_vcpus);
 
+	/* Let's tell the UV that we want to change into the stopped state */
+	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+		r = kvm_s390_pv_set_cpu_state(vcpu, PV_CPU_STATE_STP);
+		if (r) {
+			spin_unlock(&vcpu->kvm->arch.start_stop_lock);
+			return r;
+		}
+	}
+
 	/* SIGP STOP and SIGP STOP AND STORE STATUS has been fully processed */
 	kvm_s390_clear_stop_irq(vcpu);
 
@@ -4527,7 +4551,7 @@ void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
 	}
 
 	spin_unlock(&vcpu->kvm->arch.start_stop_lock);
-	return;
+	return 0;
 }
 
 static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,

arch/s390/kvm/kvm-s390.h

@@ -217,6 +217,7 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
 			      u16 *rrc);
 int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
 		       unsigned long tweak, u16 *rc, u16 *rrc);
+int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state);
 
 static inline u64 kvm_s390_pv_get_handle(struct kvm *kvm)
 {
@@ -330,8 +331,8 @@ void kvm_s390_set_tod_clock(struct kvm *kvm,
 long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable);
 int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr);
 int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr);
-void kvm_s390_vcpu_start(struct kvm_vcpu *vcpu);
-void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu);
+int kvm_s390_vcpu_start(struct kvm_vcpu *vcpu);
+int kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_block(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_unblock(struct kvm_vcpu *vcpu);
 bool kvm_s390_vcpu_sie_inhibited(struct kvm_vcpu *vcpu);

arch/s390/kvm/pv.c

@@ -283,3 +283,21 @@ int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
 		KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
 	return ret;
 }
+
+int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
+{
+	struct uv_cb_cpu_set_state uvcb = {
+		.header.cmd	= UVC_CMD_CPU_SET_STATE,
+		.header.len	= sizeof(uvcb),
+		.cpu_handle	= kvm_s390_pv_cpu_get_handle(vcpu),
+		.state		= state,
+	};
+	int cc;
+
+	cc = uv_call(0, (u64)&uvcb);
+	KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
+		     vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
+	if (cc)
+		return -EINVAL;
+	return 0;
+}