KVM: s390: sigp: separate preparation handlers

This patch introduces in preparation for further code changes separate handler
functions for:
- SIGP (RE)START - will not be allowed to terminate pending orders
- SIGP (INITIAL) CPU RESET - will be allowed to terminate certain pending orders
- unknown sigp orders

All sigp orders that require user space intervention are logged.

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

diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h
index 4957611..fad4ae2 100644 (file)
--- a/arch/s390/include/asm/sigp.h
+++ b/arch/s390/include/asm/sigp.h
@@ -10,6 +10,7 @@
 #define SIGP_RESTART                 6
 #define SIGP_STOP_AND_STORE_STATUS    9
 #define SIGP_INITIAL_CPU_RESET      11
+#define SIGP_CPU_RESET              12
 #define SIGP_SET_PREFIX                     13
 #define SIGP_STORE_STATUS_AT_ADDRESS 14
 #define SIGP_SET_ARCHITECTURE       18

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index 660a945..a9e1739 100644 (file)
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -284,11 +284,12 @@ static int __sigp_sense_running(struct kvm_vcpu *vcpu,
        return rc;
 }
 
-/* Test whether the destination CPU is available and not busy */
-static int sigp_check_callable(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
+static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
+                                  struct kvm_vcpu *dst_vcpu, u8 order_code)
 {
        struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
-       int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
+       /* handle (RE)START in user space */
+       int rc = -EOPNOTSUPP;
 
        spin_lock(&li->lock);
        if (li->action_bits & ACTION_STOP_ON_STOP)
@@ -298,6 +299,20 @@ static int sigp_check_callable(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
        return rc;
 }
 
+static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
+                                   struct kvm_vcpu *dst_vcpu, u8 order_code)
+{
+       /* handle (INITIAL) CPU RESET in user space */
+       return -EOPNOTSUPP;
+}
+
+static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
+                                 struct kvm_vcpu *dst_vcpu)
+{
+       /* handle unknown orders in user space */
+       return -EOPNOTSUPP;
+}
+
 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
                           u16 cpu_addr, u32 parameter, u64 *status_reg)
 {
@@ -350,25 +365,27 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
                rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
                break;
        case SIGP_START:
-               rc = sigp_check_callable(vcpu, dst_vcpu);
-               if (rc == SIGP_CC_ORDER_CODE_ACCEPTED)
-                       rc = -EOPNOTSUPP;    /* Handle START in user space */
+               rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
                break;
        case SIGP_RESTART:
                vcpu->stat.instruction_sigp_restart++;
-               rc = sigp_check_callable(vcpu, dst_vcpu);
-               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;
-               }
+               rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
+               break;
+       case SIGP_INITIAL_CPU_RESET:
+               rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
+               break;
+       case SIGP_CPU_RESET:
+               rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
                break;
        default:
-               rc = -EOPNOTSUPP;
+               rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
        }
 
+       if (rc == -EOPNOTSUPP)
+               VCPU_EVENT(vcpu, 4,
+                          "sigp order %u -> cpu %x: handled in user space",
+                          order_code, dst_vcpu->vcpu_id);
+
        return rc;
 }