xref: /openbmc/linux/arch/s390/kvm/intercept.c (revision 93dc544c)
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 #include "gaccess.h"
22 
23 static int handle_lctlg(struct kvm_vcpu *vcpu)
24 {
25 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
26 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
27 	int base2 = vcpu->arch.sie_block->ipb >> 28;
28 	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16) +
29 			((vcpu->arch.sie_block->ipb & 0xff00) << 4);
30 	u64 useraddr;
31 	int reg, rc;
32 
33 	vcpu->stat.instruction_lctlg++;
34 	if ((vcpu->arch.sie_block->ipb & 0xff) != 0x2f)
35 		return -ENOTSUPP;
36 
37 	useraddr = disp2;
38 	if (base2)
39 		useraddr += vcpu->arch.guest_gprs[base2];
40 
41 	if (useraddr & 7)
42 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
43 
44 	reg = reg1;
45 
46 	VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
47 		   disp2);
48 
49 	do {
50 		rc = get_guest_u64(vcpu, useraddr,
51 				   &vcpu->arch.sie_block->gcr[reg]);
52 		if (rc == -EFAULT) {
53 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
54 			break;
55 		}
56 		useraddr += 8;
57 		if (reg == reg3)
58 			break;
59 		reg = (reg + 1) % 16;
60 	} while (1);
61 	return 0;
62 }
63 
64 static int handle_lctl(struct kvm_vcpu *vcpu)
65 {
66 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
67 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
68 	int base2 = vcpu->arch.sie_block->ipb >> 28;
69 	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
70 	u64 useraddr;
71 	u32 val = 0;
72 	int reg, rc;
73 
74 	vcpu->stat.instruction_lctl++;
75 
76 	useraddr = disp2;
77 	if (base2)
78 		useraddr += vcpu->arch.guest_gprs[base2];
79 
80 	if (useraddr & 3)
81 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
82 
83 	VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
84 		   disp2);
85 
86 	reg = reg1;
87 	do {
88 		rc = get_guest_u32(vcpu, useraddr, &val);
89 		if (rc == -EFAULT) {
90 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
91 			break;
92 		}
93 		vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
94 		vcpu->arch.sie_block->gcr[reg] |= val;
95 		useraddr += 4;
96 		if (reg == reg3)
97 			break;
98 		reg = (reg + 1) % 16;
99 	} while (1);
100 	return 0;
101 }
102 
103 static intercept_handler_t instruction_handlers[256] = {
104 	[0x83] = kvm_s390_handle_diag,
105 	[0xae] = kvm_s390_handle_sigp,
106 	[0xb2] = kvm_s390_handle_priv,
107 	[0xb7] = handle_lctl,
108 	[0xeb] = handle_lctlg,
109 };
110 
111 static int handle_noop(struct kvm_vcpu *vcpu)
112 {
113 	switch (vcpu->arch.sie_block->icptcode) {
114 	case 0x0:
115 		vcpu->stat.exit_null++;
116 		break;
117 	case 0x10:
118 		vcpu->stat.exit_external_request++;
119 		break;
120 	case 0x14:
121 		vcpu->stat.exit_external_interrupt++;
122 		break;
123 	default:
124 		break; /* nothing */
125 	}
126 	return 0;
127 }
128 
129 static int handle_stop(struct kvm_vcpu *vcpu)
130 {
131 	int rc;
132 
133 	vcpu->stat.exit_stop_request++;
134 	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
135 	spin_lock_bh(&vcpu->arch.local_int.lock);
136 	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
137 		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
138 		rc = __kvm_s390_vcpu_store_status(vcpu,
139 						  KVM_S390_STORE_STATUS_NOADDR);
140 		if (rc >= 0)
141 			rc = -ENOTSUPP;
142 	}
143 
144 	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
145 		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
146 		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
147 		rc = -ENOTSUPP;
148 	} else
149 		rc = 0;
150 	spin_unlock_bh(&vcpu->arch.local_int.lock);
151 	return rc;
152 }
153 
154 static int handle_validity(struct kvm_vcpu *vcpu)
155 {
156 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
157 	vcpu->stat.exit_validity++;
158 	if (viwhy == 0x37) {
159 		fault_in_pages_writeable((char __user *)
160 					 vcpu->kvm->arch.guest_origin +
161 					 vcpu->arch.sie_block->prefix,
162 					 PAGE_SIZE);
163 		return 0;
164 	}
165 	VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
166 		   viwhy);
167 	return -ENOTSUPP;
168 }
169 
170 static int handle_instruction(struct kvm_vcpu *vcpu)
171 {
172 	intercept_handler_t handler;
173 
174 	vcpu->stat.exit_instruction++;
175 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
176 	if (handler)
177 		return handler(vcpu);
178 	return -ENOTSUPP;
179 }
180 
181 static int handle_prog(struct kvm_vcpu *vcpu)
182 {
183 	vcpu->stat.exit_program_interruption++;
184 	return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
185 }
186 
187 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
188 {
189 	int rc, rc2;
190 
191 	vcpu->stat.exit_instr_and_program++;
192 	rc = handle_instruction(vcpu);
193 	rc2 = handle_prog(vcpu);
194 
195 	if (rc == -ENOTSUPP)
196 		vcpu->arch.sie_block->icptcode = 0x04;
197 	if (rc)
198 		return rc;
199 	return rc2;
200 }
201 
202 static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
203 	[0x00 >> 2] = handle_noop,
204 	[0x04 >> 2] = handle_instruction,
205 	[0x08 >> 2] = handle_prog,
206 	[0x0C >> 2] = handle_instruction_and_prog,
207 	[0x10 >> 2] = handle_noop,
208 	[0x14 >> 2] = handle_noop,
209 	[0x1C >> 2] = kvm_s390_handle_wait,
210 	[0x20 >> 2] = handle_validity,
211 	[0x28 >> 2] = handle_stop,
212 };
213 
214 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
215 {
216 	intercept_handler_t func;
217 	u8 code = vcpu->arch.sie_block->icptcode;
218 
219 	if (code & 3 || code > 0x48)
220 		return -ENOTSUPP;
221 	func = intercept_funcs[code >> 2];
222 	if (func)
223 		return func(vcpu);
224 	return -ENOTSUPP;
225 }
226