KVM: s390: SIGP SET PREFIX cleanup

This patch cleanes up the the SIGP SET PREFIX code.

A SIGP SET PREFIX irq may only be injected if the target vcpu is
stopped. Let's move the checking code into the injection code and
return -EBUSY if the target vcpu is not stopped.

Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index f753c0b..1ba9176 100644 (file)
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1026,6 +1026,9 @@ static int __inject_set_prefix(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq)
        trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, KVM_S390_SIGP_SET_PREFIX,
                                   prefix->address, 0, 2);
 
+       if (!is_vcpu_stopped(vcpu))
+               return -EBUSY;
+
        *prefix = irq->u.prefix;
        set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
        return 0;

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index a251854..8ae4495 100644 (file)
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -176,41 +176,33 @@ static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
                             u32 address, u64 *reg)
 {
-       struct kvm_s390_local_interrupt *li;
+       struct kvm_s390_irq irq = {
+               .type = KVM_S390_SIGP_SET_PREFIX,
+               .u.prefix.address = address & 0x7fffe000u,
+       };
        int rc;
 
-       li = &dst_vcpu->arch.local_int;
-
        /*
         * Make sure the new value is valid memory. We only need to check the
         * first page, since address is 8k aligned and memory pieces are always
         * at least 1MB aligned and have at least a size of 1MB.
         */
-       address &= 0x7fffe000u;
-       if (kvm_is_error_gpa(vcpu->kvm, address)) {
+       if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
                *reg &= 0xffffffff00000000UL;
                *reg |= SIGP_STATUS_INVALID_PARAMETER;
                return SIGP_CC_STATUS_STORED;
        }
 
-       spin_lock(&li->lock);
-       /* cpu must be in stopped state */
-       if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
+       rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+       if (rc == -EBUSY) {
                *reg &= 0xffffffff00000000UL;
                *reg |= SIGP_STATUS_INCORRECT_STATE;
-               rc = SIGP_CC_STATUS_STORED;
-               goto out_li;
+               return SIGP_CC_STATUS_STORED;
+       } else if (rc == 0) {
+               VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x",
+                          dst_vcpu->vcpu_id, irq.u.prefix.address);
        }
 
-       li->irq.prefix.address = address;
-       set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
-       kvm_s390_vcpu_wakeup(dst_vcpu);
-       rc = SIGP_CC_ORDER_CODE_ACCEPTED;
-
-       VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", dst_vcpu->vcpu_id,
-                  address);
-out_li:
-       spin_unlock(&li->lock);
        return rc;
 }