xref: /openbmc/linux/arch/s390/kvm/sigp.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * sigp.c - handlinge interprocessor communication
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.h>
15 #include <linux/kvm_host.h>
16 #include "gaccess.h"
17 #include "kvm-s390.h"
18 
19 /* sigp order codes */
20 #define SIGP_SENSE             0x01
21 #define SIGP_EXTERNAL_CALL     0x02
22 #define SIGP_EMERGENCY         0x03
23 #define SIGP_START             0x04
24 #define SIGP_STOP              0x05
25 #define SIGP_RESTART           0x06
26 #define SIGP_STOP_STORE_STATUS 0x09
27 #define SIGP_INITIAL_CPU_RESET 0x0b
28 #define SIGP_CPU_RESET         0x0c
29 #define SIGP_SET_PREFIX        0x0d
30 #define SIGP_STORE_STATUS_ADDR 0x0e
31 #define SIGP_SET_ARCH          0x12
32 
33 /* cpu status bits */
34 #define SIGP_STAT_EQUIPMENT_CHECK   0x80000000UL
35 #define SIGP_STAT_INCORRECT_STATE   0x00000200UL
36 #define SIGP_STAT_INVALID_PARAMETER 0x00000100UL
37 #define SIGP_STAT_EXT_CALL_PENDING  0x00000080UL
38 #define SIGP_STAT_STOPPED           0x00000040UL
39 #define SIGP_STAT_OPERATOR_INTERV   0x00000020UL
40 #define SIGP_STAT_CHECK_STOP        0x00000010UL
41 #define SIGP_STAT_INOPERATIVE       0x00000004UL
42 #define SIGP_STAT_INVALID_ORDER     0x00000002UL
43 #define SIGP_STAT_RECEIVER_CHECK    0x00000001UL
44 
45 
46 static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr,
47 			unsigned long *reg)
48 {
49 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
50 	int rc;
51 
52 	if (cpu_addr >= KVM_MAX_VCPUS)
53 		return 3; /* not operational */
54 
55 	spin_lock_bh(&fi->lock);
56 	if (fi->local_int[cpu_addr] == NULL)
57 		rc = 3; /* not operational */
58 	else if (atomic_read(fi->local_int[cpu_addr]->cpuflags)
59 		 & CPUSTAT_RUNNING) {
60 		*reg &= 0xffffffff00000000UL;
61 		rc = 1; /* status stored */
62 	} else {
63 		*reg &= 0xffffffff00000000UL;
64 		*reg |= SIGP_STAT_STOPPED;
65 		rc = 1; /* status stored */
66 	}
67 	spin_unlock_bh(&fi->lock);
68 
69 	VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", cpu_addr, rc);
70 	return rc;
71 }
72 
73 static int __sigp_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr)
74 {
75 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
76 	struct kvm_s390_local_interrupt *li;
77 	struct kvm_s390_interrupt_info *inti;
78 	int rc;
79 
80 	if (cpu_addr >= KVM_MAX_VCPUS)
81 		return 3; /* not operational */
82 
83 	inti = kzalloc(sizeof(*inti), GFP_KERNEL);
84 	if (!inti)
85 		return -ENOMEM;
86 
87 	inti->type = KVM_S390_INT_EMERGENCY;
88 
89 	spin_lock_bh(&fi->lock);
90 	li = fi->local_int[cpu_addr];
91 	if (li == NULL) {
92 		rc = 3; /* not operational */
93 		kfree(inti);
94 		goto unlock;
95 	}
96 	spin_lock_bh(&li->lock);
97 	list_add_tail(&inti->list, &li->list);
98 	atomic_set(&li->active, 1);
99 	atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
100 	if (waitqueue_active(&li->wq))
101 		wake_up_interruptible(&li->wq);
102 	spin_unlock_bh(&li->lock);
103 	rc = 0; /* order accepted */
104 unlock:
105 	spin_unlock_bh(&fi->lock);
106 	VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
107 	return rc;
108 }
109 
110 static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int store)
111 {
112 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
113 	struct kvm_s390_local_interrupt *li;
114 	struct kvm_s390_interrupt_info *inti;
115 	int rc;
116 
117 	if (cpu_addr >= KVM_MAX_VCPUS)
118 		return 3; /* not operational */
119 
120 	inti = kzalloc(sizeof(*inti), GFP_KERNEL);
121 	if (!inti)
122 		return -ENOMEM;
123 
124 	inti->type = KVM_S390_SIGP_STOP;
125 
126 	spin_lock_bh(&fi->lock);
127 	li = fi->local_int[cpu_addr];
128 	if (li == NULL) {
129 		rc = 3; /* not operational */
130 		kfree(inti);
131 		goto unlock;
132 	}
133 	spin_lock_bh(&li->lock);
134 	list_add_tail(&inti->list, &li->list);
135 	atomic_set(&li->active, 1);
136 	atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
137 	if (store)
138 		li->action_bits |= ACTION_STORE_ON_STOP;
139 	li->action_bits |= ACTION_STOP_ON_STOP;
140 	if (waitqueue_active(&li->wq))
141 		wake_up_interruptible(&li->wq);
142 	spin_unlock_bh(&li->lock);
143 	rc = 0; /* order accepted */
144 unlock:
145 	spin_unlock_bh(&fi->lock);
146 	VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);
147 	return rc;
148 }
149 
150 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
151 {
152 	int rc;
153 
154 	switch (parameter & 0xff) {
155 	case 0:
156 		rc = 3; /* not operational */
157 		break;
158 	case 1:
159 	case 2:
160 		rc = 0; /* order accepted */
161 		break;
162 	default:
163 		rc = -ENOTSUPP;
164 	}
165 	return rc;
166 }
167 
168 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
169 			     unsigned long *reg)
170 {
171 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
172 	struct kvm_s390_local_interrupt *li;
173 	struct kvm_s390_interrupt_info *inti;
174 	int rc;
175 	u8 tmp;
176 
177 	/* make sure that the new value is valid memory */
178 	address = address & 0x7fffe000u;
179 	if ((copy_from_guest(vcpu, &tmp,
180 		(u64) (address + vcpu->kvm->arch.guest_origin) , 1)) ||
181 	   (copy_from_guest(vcpu, &tmp, (u64) (address +
182 			vcpu->kvm->arch.guest_origin + PAGE_SIZE), 1))) {
183 		*reg |= SIGP_STAT_INVALID_PARAMETER;
184 		return 1; /* invalid parameter */
185 	}
186 
187 	inti = kzalloc(sizeof(*inti), GFP_KERNEL);
188 	if (!inti)
189 		return 2; /* busy */
190 
191 	spin_lock_bh(&fi->lock);
192 	li = fi->local_int[cpu_addr];
193 
194 	if ((cpu_addr >= KVM_MAX_VCPUS) || (li == NULL)) {
195 		rc = 1; /* incorrect state */
196 		*reg &= SIGP_STAT_INCORRECT_STATE;
197 		kfree(inti);
198 		goto out_fi;
199 	}
200 
201 	spin_lock_bh(&li->lock);
202 	/* cpu must be in stopped state */
203 	if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
204 		rc = 1; /* incorrect state */
205 		*reg &= SIGP_STAT_INCORRECT_STATE;
206 		kfree(inti);
207 		goto out_li;
208 	}
209 
210 	inti->type = KVM_S390_SIGP_SET_PREFIX;
211 	inti->prefix.address = address;
212 
213 	list_add_tail(&inti->list, &li->list);
214 	atomic_set(&li->active, 1);
215 	if (waitqueue_active(&li->wq))
216 		wake_up_interruptible(&li->wq);
217 	rc = 0; /* order accepted */
218 
219 	VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
220 out_li:
221 	spin_unlock_bh(&li->lock);
222 out_fi:
223 	spin_unlock_bh(&fi->lock);
224 	return rc;
225 }
226 
227 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
228 {
229 	int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
230 	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
231 	int base2 = vcpu->arch.sie_block->ipb >> 28;
232 	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
233 	u32 parameter;
234 	u16 cpu_addr = vcpu->arch.guest_gprs[r3];
235 	u8 order_code;
236 	int rc;
237 
238 	/* sigp in userspace can exit */
239 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
240 		return kvm_s390_inject_program_int(vcpu,
241 						   PGM_PRIVILEGED_OPERATION);
242 
243 	order_code = disp2;
244 	if (base2)
245 		order_code += vcpu->arch.guest_gprs[base2];
246 
247 	if (r1 % 2)
248 		parameter = vcpu->arch.guest_gprs[r1];
249 	else
250 		parameter = vcpu->arch.guest_gprs[r1 + 1];
251 
252 	switch (order_code) {
253 	case SIGP_SENSE:
254 		vcpu->stat.instruction_sigp_sense++;
255 		rc = __sigp_sense(vcpu, cpu_addr,
256 				  &vcpu->arch.guest_gprs[r1]);
257 		break;
258 	case SIGP_EMERGENCY:
259 		vcpu->stat.instruction_sigp_emergency++;
260 		rc = __sigp_emergency(vcpu, cpu_addr);
261 		break;
262 	case SIGP_STOP:
263 		vcpu->stat.instruction_sigp_stop++;
264 		rc = __sigp_stop(vcpu, cpu_addr, 0);
265 		break;
266 	case SIGP_STOP_STORE_STATUS:
267 		vcpu->stat.instruction_sigp_stop++;
268 		rc = __sigp_stop(vcpu, cpu_addr, 1);
269 		break;
270 	case SIGP_SET_ARCH:
271 		vcpu->stat.instruction_sigp_arch++;
272 		rc = __sigp_set_arch(vcpu, parameter);
273 		break;
274 	case SIGP_SET_PREFIX:
275 		vcpu->stat.instruction_sigp_prefix++;
276 		rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
277 				       &vcpu->arch.guest_gprs[r1]);
278 		break;
279 	case SIGP_RESTART:
280 		vcpu->stat.instruction_sigp_restart++;
281 		/* user space must know about restart */
282 	default:
283 		return -ENOTSUPP;
284 	}
285 
286 	if (rc < 0)
287 		return rc;
288 
289 	vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
290 	vcpu->arch.sie_block->gpsw.mask |= (rc & 3ul) << 44;
291 	return 0;
292 }
293