arch/s390/kvm/diag.c

   1 /*
   2  * diag.c - handling diagnose instructions
   3  *
   4  * Copyright IBM Corp. 2008,2011
   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_release_pages(struct kvm_vcpu *vcpu)
  19 {
  20         unsigned long start, end;
  21         unsigned long prefix  = vcpu->arch.sie_block->prefix;
  22
  23         start = vcpu->arch.guest_gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
  24         end = vcpu->arch.guest_gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
  25
  26         if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
  27             || start < 2 * PAGE_SIZE)
  28                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  29
  30         VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
  31         vcpu->stat.diagnose_10++;
  32
  33         /* we checked for start > end above */
  34         if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
  35                 gmap_discard(start, end, vcpu->arch.gmap);
  36         } else {
  37                 if (start < prefix)
  38                         gmap_discard(start, prefix, vcpu->arch.gmap);
  39                 if (end >= prefix)
  40                         gmap_discard(prefix + 2 * PAGE_SIZE,
  41                                      end, vcpu->arch.gmap);
  42         }
  43         return 0;
  44 }
  45
  46 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
  47 {
  48         VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
  49         vcpu->stat.diagnose_44++;
  50         vcpu_put(vcpu);
  51         yield();
  52         vcpu_load(vcpu);
  53         return 0;
  54 }
  55
  56 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
  57 {
  58         unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
  59         unsigned long subcode = vcpu->arch.guest_gprs[reg] & 0xffff;
  60
  61         VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
  62         switch (subcode) {
  63         case 3:
  64                 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
  65                 break;
  66         case 4:
  67                 vcpu->run->s390_reset_flags = 0;
  68                 break;
  69         default:
  70                 return -EOPNOTSUPP;
  71         }
  72
  73         atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
  74         vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
  75         vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
  76         vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
  77         vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
  78         VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
  79           vcpu->run->s390_reset_flags);
  80         return -EREMOTE;
  81 }
  82
  83 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
  84 {
  85         int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
  86
  87         switch (code) {
  88         case 0x10:
  89                 return diag_release_pages(vcpu);
  90         case 0x44:
  91                 return __diag_time_slice_end(vcpu);
  92         case 0x308:
  93                 return __diag_ipl_functions(vcpu);
  94         default:
  95                 return -EOPNOTSUPP;
  96         }
  97 }