KVM: s390: Split up __vcpu_run into three parts

In preparation for the following patch (which will change the indentation
of __vcpu_run quite a bit), this patch puts most of the code from __vcpu_run
into separate functions. The first function handles the code that runs
before the SIE instruction and the other one handles the code that runs
afterwards.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 37 insertions, 17 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e3e7ff77ba44..69c7592e80d9 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -689,9 +689,9 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
         return 0;
 }
 
-static int __vcpu_run(struct kvm_vcpu *vcpu)
+static int vcpu_pre_run(struct kvm_vcpu *vcpu)
 {
-        int rc;
+        int rc, cpuflags;
 
         memcpy(&vcpu->arch.sie_block->gg14, &vcpu->run->s.regs.gprs[14], 16);
 
@@ -709,28 +709,24 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
                 return rc;
 
         vcpu->arch.sie_block->icptcode = 0;
-        VCPU_EVENT(vcpu, 6, "entering sie flags %x",
-                   atomic_read(&vcpu->arch.sie_block->cpuflags));
-        trace_kvm_s390_sie_enter(vcpu,
-                                 atomic_read(&vcpu->arch.sie_block->cpuflags));
+        cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
+        VCPU_EVENT(vcpu, 6, "entering sie flags %x", cpuflags);
+        trace_kvm_s390_sie_enter(vcpu, cpuflags);
 
-        /*
-         * As PF_VCPU will be used in fault handler, between guest_enter
-         * and guest_exit should be no uaccess.
-         */
-        preempt_disable();
-        kvm_guest_enter();
-        preempt_enable();
-        rc = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs);
-        kvm_guest_exit();
+        return 0;
+}
+
+static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
+{
+        int rc;
 
         VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
                    vcpu->arch.sie_block->icptcode);
         trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode);
 
-        if (rc > 0)
+        if (exit_reason >= 0) {
                 rc = 0;
-        if (rc < 0) {
+        } else {
                 if (kvm_is_ucontrol(vcpu->kvm)) {
                         rc = SIE_INTERCEPT_UCONTROL;
                 } else {
@@ -741,6 +737,30 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
         }
 
         memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16);
+
+        return rc;
+}
+
+static int __vcpu_run(struct kvm_vcpu *vcpu)
+{
+        int rc, exit_reason;
+
+        rc = vcpu_pre_run(vcpu);
+        if (rc)
+                return rc;
+
+        /*
+         * As PF_VCPU will be used in fault handler, between guest_enter
+         * and guest_exit should be no uaccess.
+         */
+        preempt_disable();
+        kvm_guest_enter();
+        preempt_enable();
+        exit_reason = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs);
+        kvm_guest_exit();
+
+        rc = vcpu_post_run(vcpu, exit_reason);
+
         return rc;
 }