arch/s390/kvm/intercept.c

   1 /*
   2  * intercept.c - in-kernel handling for sie intercepts
   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_host.h>
  15 #include <linux/errno.h>
  16 #include <linux/pagemap.h>
  17
  18 #include <asm/kvm_host.h>
  19
  20 #include "kvm-s390.h"
  21
  22 static int handle_noop(struct kvm_vcpu *vcpu)
  23 {
  24         switch (vcpu->arch.sie_block->icptcode) {
  25         case 0x10:
  26                 vcpu->stat.exit_external_request++;
  27                 break;
  28         case 0x14:
  29                 vcpu->stat.exit_external_interrupt++;
  30                 break;
  31         default:
  32                 break; /* nothing */
  33         }
  34         return 0;
  35 }
  36
  37 static int handle_stop(struct kvm_vcpu *vcpu)
  38 {
  39         vcpu->stat.exit_stop_request++;
  40         VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
  41         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
  42         return -ENOTSUPP;
  43 }
  44
  45 static int handle_validity(struct kvm_vcpu *vcpu)
  46 {
  47         int viwhy = vcpu->arch.sie_block->ipb >> 16;
  48         vcpu->stat.exit_validity++;
  49         if (viwhy == 0x37) {
  50                 fault_in_pages_writeable((char __user *)
  51                                          vcpu->kvm->arch.guest_origin +
  52                                          vcpu->arch.sie_block->prefix,
  53                                          PAGE_SIZE);
  54                 return 0;
  55         }
  56         VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
  57                    viwhy);
  58         return -ENOTSUPP;
  59 }
  60
  61 static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
  62         [0x00 >> 2] = handle_noop,
  63         [0x10 >> 2] = handle_noop,
  64         [0x14 >> 2] = handle_noop,
  65         [0x20 >> 2] = handle_validity,
  66         [0x28 >> 2] = handle_stop,
  67 };
  68
  69 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
  70 {
  71         intercept_handler_t func;
  72         u8 code = vcpu->arch.sie_block->icptcode;
  73
  74         if (code & 3 || code > 0x48)
  75                 return -ENOTSUPP;
  76         func = intercept_funcs[code >> 2];
  77         if (func)
  78                 return func(vcpu);
  79         return -ENOTSUPP;
  80 }