xref: /openbmc/linux/arch/s390/kvm/intercept.c (revision 545e4006)
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_lctg(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_lctg++;
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 	reg = reg1;
42 
43 	VCPU_EVENT(vcpu, 5, "lctg r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
44 		   disp2);
45 
46 	do {
47 		rc = get_guest_u64(vcpu, useraddr,
48 				   &vcpu->arch.sie_block->gcr[reg]);
49 		if (rc == -EFAULT) {
50 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
51 			break;
52 		}
53 		useraddr += 8;
54 		if (reg == reg3)
55 			break;
56 		reg = (reg + 1) % 16;
57 	} while (1);
58 	return 0;
59 }
60 
61 static int handle_lctl(struct kvm_vcpu *vcpu)
62 {
63 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
64 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
65 	int base2 = vcpu->arch.sie_block->ipb >> 28;
66 	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
67 	u64 useraddr;
68 	u32 val = 0;
69 	int reg, rc;
70 
71 	vcpu->stat.instruction_lctl++;
72 
73 	useraddr = disp2;
74 	if (base2)
75 		useraddr += vcpu->arch.guest_gprs[base2];
76 
77 	VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
78 		   disp2);
79 
80 	reg = reg1;
81 	do {
82 		rc = get_guest_u32(vcpu, useraddr, &val);
83 		if (rc == -EFAULT) {
84 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
85 			break;
86 		}
87 		vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
88 		vcpu->arch.sie_block->gcr[reg] |= val;
89 		useraddr += 4;
90 		if (reg == reg3)
91 			break;
92 		reg = (reg + 1) % 16;
93 	} while (1);
94 	return 0;
95 }
96 
97 static intercept_handler_t instruction_handlers[256] = {
98 	[0x83] = kvm_s390_handle_diag,
99 	[0xae] = kvm_s390_handle_sigp,
100 	[0xb2] = kvm_s390_handle_priv,
101 	[0xb7] = handle_lctl,
102 	[0xeb] = handle_lctg,
103 };
104 
105 static int handle_noop(struct kvm_vcpu *vcpu)
106 {
107 	switch (vcpu->arch.sie_block->icptcode) {
108 	case 0x0:
109 		vcpu->stat.exit_null++;
110 		break;
111 	case 0x10:
112 		vcpu->stat.exit_external_request++;
113 		break;
114 	case 0x14:
115 		vcpu->stat.exit_external_interrupt++;
116 		break;
117 	default:
118 		break; /* nothing */
119 	}
120 	return 0;
121 }
122 
123 static int handle_stop(struct kvm_vcpu *vcpu)
124 {
125 	int rc;
126 
127 	vcpu->stat.exit_stop_request++;
128 	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
129 	spin_lock_bh(&vcpu->arch.local_int.lock);
130 	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
131 		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
132 		rc = __kvm_s390_vcpu_store_status(vcpu,
133 						  KVM_S390_STORE_STATUS_NOADDR);
134 		if (rc >= 0)
135 			rc = -ENOTSUPP;
136 	}
137 
138 	if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
139 		vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
140 		VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
141 		rc = -ENOTSUPP;
142 	} else
143 		rc = 0;
144 	spin_unlock_bh(&vcpu->arch.local_int.lock);
145 	return rc;
146 }
147 
148 static int handle_validity(struct kvm_vcpu *vcpu)
149 {
150 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
151 	vcpu->stat.exit_validity++;
152 	if (viwhy == 0x37) {
153 		fault_in_pages_writeable((char __user *)
154 					 vcpu->kvm->arch.guest_origin +
155 					 vcpu->arch.sie_block->prefix,
156 					 PAGE_SIZE);
157 		return 0;
158 	}
159 	VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
160 		   viwhy);
161 	return -ENOTSUPP;
162 }
163 
164 static int handle_instruction(struct kvm_vcpu *vcpu)
165 {
166 	intercept_handler_t handler;
167 
168 	vcpu->stat.exit_instruction++;
169 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
170 	if (handler)
171 		return handler(vcpu);
172 	return -ENOTSUPP;
173 }
174 
175 static int handle_prog(struct kvm_vcpu *vcpu)
176 {
177 	vcpu->stat.exit_program_interruption++;
178 	return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
179 }
180 
181 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
182 {
183 	int rc, rc2;
184 
185 	vcpu->stat.exit_instr_and_program++;
186 	rc = handle_instruction(vcpu);
187 	rc2 = handle_prog(vcpu);
188 
189 	if (rc == -ENOTSUPP)
190 		vcpu->arch.sie_block->icptcode = 0x04;
191 	if (rc)
192 		return rc;
193 	return rc2;
194 }
195 
196 static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
197 	[0x00 >> 2] = handle_noop,
198 	[0x04 >> 2] = handle_instruction,
199 	[0x08 >> 2] = handle_prog,
200 	[0x0C >> 2] = handle_instruction_and_prog,
201 	[0x10 >> 2] = handle_noop,
202 	[0x14 >> 2] = handle_noop,
203 	[0x1C >> 2] = kvm_s390_handle_wait,
204 	[0x20 >> 2] = handle_validity,
205 	[0x28 >> 2] = handle_stop,
206 };
207 
208 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
209 {
210 	intercept_handler_t func;
211 	u8 code = vcpu->arch.sie_block->icptcode;
212 
213 	if (code & 3 || code > 0x48)
214 		return -ENOTSUPP;
215 	func = intercept_funcs[code >> 2];
216 	if (func)
217 		return func(vcpu);
218 	return -ENOTSUPP;
219 }
220