xref: /openbmc/linux/arch/s390/kvm/intercept.c (revision 39b6f3aa)
1 /*
2  * in-kernel handling for sie intercepts
3  *
4  * Copyright IBM Corp. 2008, 2009
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 #include "trace.h"
23 #include "trace-s390.h"
24 
25 static int handle_lctlg(struct kvm_vcpu *vcpu)
26 {
27 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
28 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
29 	u64 useraddr;
30 	int reg, rc;
31 
32 	vcpu->stat.instruction_lctlg++;
33 
34 	useraddr = kvm_s390_get_base_disp_rsy(vcpu);
35 
36 	if (useraddr & 7)
37 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
38 
39 	reg = reg1;
40 
41 	VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x, addr:%llx", reg1, reg3,
42 		   useraddr);
43 	trace_kvm_s390_handle_lctl(vcpu, 1, reg1, reg3, useraddr);
44 
45 	do {
46 		rc = get_guest(vcpu, vcpu->arch.sie_block->gcr[reg],
47 			       (u64 __user *) useraddr);
48 		if (rc)
49 			return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
50 		useraddr += 8;
51 		if (reg == reg3)
52 			break;
53 		reg = (reg + 1) % 16;
54 	} while (1);
55 	return 0;
56 }
57 
58 static int handle_lctl(struct kvm_vcpu *vcpu)
59 {
60 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
61 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
62 	u64 useraddr;
63 	u32 val = 0;
64 	int reg, rc;
65 
66 	vcpu->stat.instruction_lctl++;
67 
68 	useraddr = kvm_s390_get_base_disp_rs(vcpu);
69 
70 	if (useraddr & 3)
71 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
72 
73 	VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x, addr:%llx", reg1, reg3,
74 		   useraddr);
75 	trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, useraddr);
76 
77 	reg = reg1;
78 	do {
79 		rc = get_guest(vcpu, val, (u32 __user *) useraddr);
80 		if (rc)
81 			return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
82 		vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
83 		vcpu->arch.sie_block->gcr[reg] |= val;
84 		useraddr += 4;
85 		if (reg == reg3)
86 			break;
87 		reg = (reg + 1) % 16;
88 	} while (1);
89 	return 0;
90 }
91 
92 static const intercept_handler_t eb_handlers[256] = {
93 	[0x2f] = handle_lctlg,
94 	[0x8a] = kvm_s390_handle_priv_eb,
95 };
96 
97 static int handle_eb(struct kvm_vcpu *vcpu)
98 {
99 	intercept_handler_t handler;
100 
101 	handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
102 	if (handler)
103 		return handler(vcpu);
104 	return -EOPNOTSUPP;
105 }
106 
107 static const intercept_handler_t instruction_handlers[256] = {
108 	[0x01] = kvm_s390_handle_01,
109 	[0x82] = kvm_s390_handle_lpsw,
110 	[0x83] = kvm_s390_handle_diag,
111 	[0xae] = kvm_s390_handle_sigp,
112 	[0xb2] = kvm_s390_handle_b2,
113 	[0xb7] = handle_lctl,
114 	[0xb9] = kvm_s390_handle_b9,
115 	[0xe5] = kvm_s390_handle_e5,
116 	[0xeb] = handle_eb,
117 };
118 
119 static int handle_noop(struct kvm_vcpu *vcpu)
120 {
121 	switch (vcpu->arch.sie_block->icptcode) {
122 	case 0x0:
123 		vcpu->stat.exit_null++;
124 		break;
125 	case 0x10:
126 		vcpu->stat.exit_external_request++;
127 		break;
128 	case 0x14:
129 		vcpu->stat.exit_external_interrupt++;
130 		break;
131 	default:
132 		break; /* nothing */
133 	}
134 	return 0;
135 }
136 
137 static int handle_stop(struct kvm_vcpu *vcpu)
138 {
139 	int rc = 0;
140 
141 	vcpu->stat.exit_stop_request++;
142 	spin_lock_bh(&vcpu->arch.local_int.lock);
143 
144 	trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
145 
146 	if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
147 		vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
148 		rc = SIE_INTERCEPT_RERUNVCPU;
149 		vcpu->run->exit_reason = KVM_EXIT_INTR;
150 	}
151 
152 	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
153 		atomic_set_mask(CPUSTAT_STOPPED,
154 				&vcpu->arch.sie_block->cpuflags);
155 		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
156 		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
157 		rc = -EOPNOTSUPP;
158 	}
159 
160 	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
161 		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
162 		/* store status must be called unlocked. Since local_int.lock
163 		 * only protects local_int.* and not guest memory we can give
164 		 * up the lock here */
165 		spin_unlock_bh(&vcpu->arch.local_int.lock);
166 		rc = kvm_s390_vcpu_store_status(vcpu,
167 						KVM_S390_STORE_STATUS_NOADDR);
168 		if (rc >= 0)
169 			rc = -EOPNOTSUPP;
170 	} else
171 		spin_unlock_bh(&vcpu->arch.local_int.lock);
172 	return rc;
173 }
174 
175 static int handle_validity(struct kvm_vcpu *vcpu)
176 {
177 	unsigned long vmaddr;
178 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
179 	int rc;
180 
181 	vcpu->stat.exit_validity++;
182 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
183 	if (viwhy == 0x37) {
184 		vmaddr = gmap_fault(vcpu->arch.sie_block->prefix,
185 				    vcpu->arch.gmap);
186 		if (IS_ERR_VALUE(vmaddr)) {
187 			rc = -EOPNOTSUPP;
188 			goto out;
189 		}
190 		rc = fault_in_pages_writeable((char __user *) vmaddr,
191 			 PAGE_SIZE);
192 		if (rc) {
193 			/* user will receive sigsegv, exit to user */
194 			rc = -EOPNOTSUPP;
195 			goto out;
196 		}
197 		vmaddr = gmap_fault(vcpu->arch.sie_block->prefix + PAGE_SIZE,
198 				    vcpu->arch.gmap);
199 		if (IS_ERR_VALUE(vmaddr)) {
200 			rc = -EOPNOTSUPP;
201 			goto out;
202 		}
203 		rc = fault_in_pages_writeable((char __user *) vmaddr,
204 			 PAGE_SIZE);
205 		if (rc) {
206 			/* user will receive sigsegv, exit to user */
207 			rc = -EOPNOTSUPP;
208 			goto out;
209 		}
210 	} else
211 		rc = -EOPNOTSUPP;
212 
213 out:
214 	if (rc)
215 		VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
216 			   viwhy);
217 	return rc;
218 }
219 
220 static int handle_instruction(struct kvm_vcpu *vcpu)
221 {
222 	intercept_handler_t handler;
223 
224 	vcpu->stat.exit_instruction++;
225 	trace_kvm_s390_intercept_instruction(vcpu,
226 					     vcpu->arch.sie_block->ipa,
227 					     vcpu->arch.sie_block->ipb);
228 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
229 	if (handler)
230 		return handler(vcpu);
231 	return -EOPNOTSUPP;
232 }
233 
234 static int handle_prog(struct kvm_vcpu *vcpu)
235 {
236 	vcpu->stat.exit_program_interruption++;
237 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
238 	return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
239 }
240 
241 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
242 {
243 	int rc, rc2;
244 
245 	vcpu->stat.exit_instr_and_program++;
246 	rc = handle_instruction(vcpu);
247 	rc2 = handle_prog(vcpu);
248 
249 	if (rc == -EOPNOTSUPP)
250 		vcpu->arch.sie_block->icptcode = 0x04;
251 	if (rc)
252 		return rc;
253 	return rc2;
254 }
255 
256 static const intercept_handler_t intercept_funcs[] = {
257 	[0x00 >> 2] = handle_noop,
258 	[0x04 >> 2] = handle_instruction,
259 	[0x08 >> 2] = handle_prog,
260 	[0x0C >> 2] = handle_instruction_and_prog,
261 	[0x10 >> 2] = handle_noop,
262 	[0x14 >> 2] = handle_noop,
263 	[0x18 >> 2] = handle_noop,
264 	[0x1C >> 2] = kvm_s390_handle_wait,
265 	[0x20 >> 2] = handle_validity,
266 	[0x28 >> 2] = handle_stop,
267 };
268 
269 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
270 {
271 	intercept_handler_t func;
272 	u8 code = vcpu->arch.sie_block->icptcode;
273 
274 	if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
275 		return -EOPNOTSUPP;
276 	func = intercept_funcs[code >> 2];
277 	if (func)
278 		return func(vcpu);
279 	return -EOPNOTSUPP;
280 }
281