Commit 32f5ff63 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
Browse files

KVM: s390: move finalization of SIGP STOP orders to kvm_s390_vcpu_stop 



Let's move the finalization of SIGP STOP and SIGP STOP AND STORE STATUS orders to
the point where the VCPU is actually stopped.

This change is needed to prepare for a user space driven VCPU state change. The
action_bits may only be cleared when setting the cpu state to STOPPED while
holding the local irq lock.

Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 7dfc63cf

arch/s390/kvm/intercept.c

+12 −19
Original line number Diff line number Diff line
@@ -56,34 +56,27 @@ static int handle_noop(struct kvm_vcpu *vcpu) 
static int handle_stop(struct kvm_vcpu *vcpu)

{

	int rc = 0;

	unsigned int action_bits;



	vcpu->stat.exit_stop_request++;

	spin_lock_bh(&vcpu->arch.local_int.lock);



	trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);



	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {

		kvm_s390_vcpu_stop(vcpu);

		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;

		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");

		rc = -EOPNOTSUPP;

	}

	action_bits = vcpu->arch.local_int.action_bits;



	if (!(action_bits & ACTION_STOP_ON_STOP))

		return 0;



	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {

		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;

		/* store status must be called unlocked. Since local_int.lock

		 * only protects local_int.* and not guest memory we can give

		 * up the lock here */

		spin_unlock_bh(&vcpu->arch.local_int.lock);

	if (action_bits & ACTION_STORE_ON_STOP) {

		rc = kvm_s390_vcpu_store_status(vcpu,

						KVM_S390_STORE_STATUS_NOADDR);

		if (rc >= 0)

			rc = -EOPNOTSUPP;

	} else

		spin_unlock_bh(&vcpu->arch.local_int.lock);

		if (rc)

			return rc;

	}



	kvm_s390_vcpu_stop(vcpu);

	return -EOPNOTSUPP;

}



static int handle_validity(struct kvm_vcpu *vcpu)

{

	int viwhy = vcpu->arch.sie_block->ipb >> 16;

arch/s390/kvm/kvm-s390.c

+8 −0
Original line number Diff line number Diff line
@@ -1494,7 +1494,15 @@ void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu) 
	spin_lock_bh(&vcpu->kvm->arch.start_stop_lock);

	online_vcpus = atomic_read(&vcpu->kvm->online_vcpus);



	/* Need to lock access to action_bits to avoid a SIGP race condition */

	spin_lock_bh(&vcpu->arch.local_int.lock);

	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);



	/* SIGP STOP and SIGP STOP AND STORE STATUS has been fully processed */

	vcpu->arch.local_int.action_bits &=

				 ~(ACTION_STOP_ON_STOP | ACTION_STORE_ON_STOP);

	spin_unlock_bh(&vcpu->arch.local_int.lock);



	__disable_ibs_on_vcpu(vcpu);



	for (i = 0; i < online_vcpus; i++) {

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