1 /*
2 * 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 <asm/virtio-ccw.h>
17 #include "kvm-s390.h"
18 #include "trace.h"
19 #include "trace-s390.h"
20
diag_release_pages(struct kvm_vcpu * vcpu)21 static int diag_release_pages(struct kvm_vcpu *vcpu)
22 {
23 unsigned long start, end;
24 unsigned long prefix = vcpu->arch.sie_block->prefix;
25
26 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
27 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
28
29 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
30 || start < 2 * PAGE_SIZE)
31 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
32
33 VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
34 vcpu->stat.diagnose_10++;
35
36 /* we checked for start > end above */
37 if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
38 gmap_discard(start, end, vcpu->arch.gmap);
39 } else {
40 if (start < prefix)
41 gmap_discard(start, prefix, vcpu->arch.gmap);
42 if (end >= prefix)
43 gmap_discard(prefix + 2 * PAGE_SIZE,
44 end, vcpu->arch.gmap);
45 }
46 return 0;
47 }
48
__diag_time_slice_end(struct kvm_vcpu * vcpu)49 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
50 {
51 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
52 vcpu->stat.diagnose_44++;
53 kvm_vcpu_on_spin(vcpu);
54 return 0;
55 }
56
__diag_time_slice_end_directed(struct kvm_vcpu * vcpu)57 static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
58 {
59 struct kvm *kvm = vcpu->kvm;
60 struct kvm_vcpu *tcpu;
61 int tid;
62 int i;
63
64 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
65 vcpu->stat.diagnose_9c++;
66 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
67
68 if (tid == vcpu->vcpu_id)
69 return 0;
70
71 kvm_for_each_vcpu(i, tcpu, kvm)
72 if (tcpu->vcpu_id == tid) {
73 kvm_vcpu_yield_to(tcpu);
74 break;
75 }
76
77 return 0;
78 }
79
__diag_ipl_functions(struct kvm_vcpu * vcpu)80 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
81 {
82 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
83 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
84
85 VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
86 switch (subcode) {
87 case 3:
88 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
89 break;
90 case 4:
91 vcpu->run->s390_reset_flags = 0;
92 break;
93 default:
94 return -EOPNOTSUPP;
95 }
96
97 atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
98 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
99 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
100 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
101 vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
102 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
103 vcpu->run->s390_reset_flags);
104 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
105 return -EREMOTE;
106 }
107
__diag_virtio_hypercall(struct kvm_vcpu * vcpu)108 static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
109 {
110 int ret, idx;
111
112 /* No virtio-ccw notification? Get out quickly. */
113 if (!vcpu->kvm->arch.css_support ||
114 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
115 return -EOPNOTSUPP;
116
117 idx = srcu_read_lock(&vcpu->kvm->srcu);
118 /*
119 * The layout is as follows:
120 * - gpr 2 contains the subchannel id (passed as addr)
121 * - gpr 3 contains the virtqueue index (passed as datamatch)
122 */
123 ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
124 vcpu->run->s.regs.gprs[2],
125 8, &vcpu->run->s.regs.gprs[3]);
126 srcu_read_unlock(&vcpu->kvm->srcu, idx);
127 /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
128 return ret < 0 ? ret : 0;
129 }
130
kvm_s390_handle_diag(struct kvm_vcpu * vcpu)131 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
132 {
133 int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
134
135 trace_kvm_s390_handle_diag(vcpu, code);
136 switch (code) {
137 case 0x10:
138 return diag_release_pages(vcpu);
139 case 0x44:
140 return __diag_time_slice_end(vcpu);
141 case 0x9c:
142 return __diag_time_slice_end_directed(vcpu);
143 case 0x308:
144 return __diag_ipl_functions(vcpu);
145 case 0x500:
146 return __diag_virtio_hypercall(vcpu);
147 default:
148 return -EOPNOTSUPP;
149 }
150 }
151