b23d9ac77dfc77fcf090f52fc739b17cc036a69c
[pandora-kernel.git] / 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->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
24         end = vcpu->run->s.regs.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         kvm_vcpu_on_spin(vcpu);
51         return 0;
52 }
53
54 static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
55 {
56         struct kvm *kvm = vcpu->kvm;
57         struct kvm_vcpu *tcpu;
58         int tid;
59         int i;
60
61         tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
62         vcpu->stat.diagnose_9c++;
63         VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
64
65         if (tid == vcpu->vcpu_id)
66                 return 0;
67
68         kvm_for_each_vcpu(i, tcpu, kvm)
69                 if (tcpu->vcpu_id == tid) {
70                         kvm_vcpu_yield_to(tcpu);
71                         break;
72                 }
73
74         return 0;
75 }
76
77 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
78 {
79         unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
80         unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
81
82         VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
83         switch (subcode) {
84         case 3:
85                 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
86                 break;
87         case 4:
88                 vcpu->run->s390_reset_flags = 0;
89                 break;
90         default:
91                 return -EOPNOTSUPP;
92         }
93
94         atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
95         vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
96         vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
97         vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
98         vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
99         VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
100           vcpu->run->s390_reset_flags);
101         return -EREMOTE;
102 }
103
104 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
105 {
106         int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
107
108         switch (code) {
109         case 0x10:
110                 return diag_release_pages(vcpu);
111         case 0x44:
112                 return __diag_time_slice_end(vcpu);
113         case 0x9c:
114                 return __diag_time_slice_end_directed(vcpu);
115         case 0x308:
116                 return __diag_ipl_functions(vcpu);
117         default:
118                 return -EOPNOTSUPP;
119         }
120 }