arch/s390/kvm/diag.c

   1 /*
   2  * diag.c - handling diagnose instructions
   3  *
   4  * Copyright IBM Corp. 2008
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License (version 2 only)
   8  * as published by the Free Software Foundation.
   9  *
  10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  11  *               Christian Borntraeger <borntraeger@de.ibm.com>
  12  */
  13
  14 #include <linux/kvm.h>
  15 #include <linux/kvm_host.h>
  16 #include "kvm-s390.h"
  17
  18 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
  19 {
  20         VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
  21         vcpu->stat.diagnose_44++;
  22         vcpu_put(vcpu);
  23         yield();
  24         vcpu_load(vcpu);
  25         return 0;
  26 }
  27
  28 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
  29 {
  30         unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
  31         unsigned long subcode = vcpu->arch.guest_gprs[reg] & 0xffff;
  32
  33         VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
  34         switch (subcode) {
  35         case 3:
  36                 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
  37                 break;
  38         case 4:
  39                 vcpu->run->s390_reset_flags = 0;
  40                 break;
  41         default:
  42                 return -EOPNOTSUPP;
  43         }
  44
  45         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
  46         vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
  47         vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
  48         vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
  49         vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
  50         VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
  51           vcpu->run->s390_reset_flags);
  52         return -EREMOTE;
  53 }
  54
  55 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
  56 {
  57         int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
  58
  59         switch (code) {
  60         case 0x44:
  61                 return __diag_time_slice_end(vcpu);
  62         case 0x308:
  63                 return __diag_ipl_functions(vcpu);
  64         default:
  65                 return -EOPNOTSUPP;
  66         }
  67 }