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KVM: s390: Reworked SIGP RESTART order

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When SIGP RESTART detected an illegal CPU address, there is no need to
drop to userspace, we can return CC3 to the guest directly instead.
Also renamed __sigp_restart() to sigp_check_callable() (since this
is a better description of what the function is really doing) and
moved a string specific to RESTART to the calling place instead, so
that this function gets usable by other SIGP orders, too.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Thomas Huth 2013-11-27 11:47:10 +01:00 committed by Cornelia Huck
parent b13d3580ee
commit cc92d6dea1
1 changed files with 11 additions and 8 deletions
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17
arch/s390/kvm/sigp.c
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@ -363,7 +363,8 @@ static int __sigp_sense_running(struct kvm_vcpu *vcpu, u16 cpu_addr,
return rc;
}
static int __sigp_restart(struct kvm_vcpu *vcpu, u16 cpu_addr)
/* Test whether the destination CPU is available and not busy */
static int sigp_check_callable(struct kvm_vcpu *vcpu, u16 cpu_addr)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_local_interrupt *li;
@ -382,9 +383,6 @@ static int __sigp_restart(struct kvm_vcpu *vcpu, u16 cpu_addr)
spin_lock_bh(&li->lock);
if (li->action_bits & ACTION_STOP_ON_STOP)
rc = SIGP_CC_BUSY;
else
VCPU_EVENT(vcpu, 4, "sigp restart %x to handle userspace",
cpu_addr);
spin_unlock_bh(&li->lock);
out:
spin_unlock(&fi->lock);
@ -459,10 +457,15 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
break;
case SIGP_RESTART:
vcpu->stat.instruction_sigp_restart++;
rc = __sigp_restart(vcpu, cpu_addr);
if (rc == SIGP_CC_BUSY)
break;
rc = sigp_check_callable(vcpu, cpu_addr);
if (rc == SIGP_CC_ORDER_CODE_ACCEPTED) {
VCPU_EVENT(vcpu, 4,
"sigp restart %x to handle userspace",
cpu_addr);
/* user space must know about restart */
rc = -EOPNOTSUPP;
}
break;
default:
return -EOPNOTSUPP;
}