1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright IBM Corp. 2007
5  * Copyright 2011 Freescale Semiconductor, Inc.
6  *
7  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
8  */
9 
10 #include <linux/jiffies.h>
11 #include <linux/hrtimer.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/kvm_host.h>
15 #include <linux/clockchips.h>
16 
17 #include <asm/reg.h>
18 #include <asm/time.h>
19 #include <asm/byteorder.h>
20 #include <asm/kvm_ppc.h>
21 #include <asm/disassemble.h>
22 #include <asm/ppc-opcode.h>
23 #include <asm/sstep.h>
24 #include "timing.h"
25 #include "trace.h"
26 
27 #ifdef CONFIG_PPC_FPU
28 static bool kvmppc_check_fp_disabled(struct kvm_vcpu *vcpu)
29 {
30 	if (!(kvmppc_get_msr(vcpu) & MSR_FP)) {
31 		kvmppc_core_queue_fpunavail(vcpu);
32 		return true;
33 	}
34 
35 	return false;
36 }
37 #endif /* CONFIG_PPC_FPU */
38 
39 #ifdef CONFIG_VSX
40 static bool kvmppc_check_vsx_disabled(struct kvm_vcpu *vcpu)
41 {
42 	if (!(kvmppc_get_msr(vcpu) & MSR_VSX)) {
43 		kvmppc_core_queue_vsx_unavail(vcpu);
44 		return true;
45 	}
46 
47 	return false;
48 }
49 #endif /* CONFIG_VSX */
50 
51 #ifdef CONFIG_ALTIVEC
52 static bool kvmppc_check_altivec_disabled(struct kvm_vcpu *vcpu)
53 {
54 	if (!(kvmppc_get_msr(vcpu) & MSR_VEC)) {
55 		kvmppc_core_queue_vec_unavail(vcpu);
56 		return true;
57 	}
58 
59 	return false;
60 }
61 #endif /* CONFIG_ALTIVEC */
62 
63 /*
64  * XXX to do:
65  * lfiwax, lfiwzx
66  * vector loads and stores
67  *
68  * Instructions that trap when used on cache-inhibited mappings
69  * are not emulated here: multiple and string instructions,
70  * lq/stq, and the load-reserve/store-conditional instructions.
71  */
72 int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
73 {
74 	u32 inst;
75 	enum emulation_result emulated = EMULATE_FAIL;
76 	int advance = 1;
77 	struct instruction_op op;
78 
79 	/* this default type might be overwritten by subcategories */
80 	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
81 
82 	emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
83 	if (emulated != EMULATE_DONE)
84 		return emulated;
85 
86 	vcpu->arch.mmio_vsx_copy_nums = 0;
87 	vcpu->arch.mmio_vsx_offset = 0;
88 	vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
89 	vcpu->arch.mmio_sp64_extend = 0;
90 	vcpu->arch.mmio_sign_extend = 0;
91 	vcpu->arch.mmio_vmx_copy_nums = 0;
92 	vcpu->arch.mmio_vmx_offset = 0;
93 	vcpu->arch.mmio_host_swabbed = 0;
94 
95 	emulated = EMULATE_FAIL;
96 	vcpu->arch.regs.msr = vcpu->arch.shared->msr;
97 	if (analyse_instr(&op, &vcpu->arch.regs, ppc_inst(inst)) == 0) {
98 		int type = op.type & INSTR_TYPE_MASK;
99 		int size = GETSIZE(op.type);
100 
101 		switch (type) {
102 		case LOAD:  {
103 			int instr_byte_swap = op.type & BYTEREV;
104 
105 			if (op.type & SIGNEXT)
106 				emulated = kvmppc_handle_loads(vcpu,
107 						op.reg, size, !instr_byte_swap);
108 			else
109 				emulated = kvmppc_handle_load(vcpu,
110 						op.reg, size, !instr_byte_swap);
111 
112 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
113 				kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
114 
115 			break;
116 		}
117 #ifdef CONFIG_PPC_FPU
118 		case LOAD_FP:
119 			if (kvmppc_check_fp_disabled(vcpu))
120 				return EMULATE_DONE;
121 
122 			if (op.type & FPCONV)
123 				vcpu->arch.mmio_sp64_extend = 1;
124 
125 			if (op.type & SIGNEXT)
126 				emulated = kvmppc_handle_loads(vcpu,
127 					     KVM_MMIO_REG_FPR|op.reg, size, 1);
128 			else
129 				emulated = kvmppc_handle_load(vcpu,
130 					     KVM_MMIO_REG_FPR|op.reg, size, 1);
131 
132 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
133 				kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
134 
135 			break;
136 #endif
137 #ifdef CONFIG_ALTIVEC
138 		case LOAD_VMX:
139 			if (kvmppc_check_altivec_disabled(vcpu))
140 				return EMULATE_DONE;
141 
142 			/* Hardware enforces alignment of VMX accesses */
143 			vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
144 			vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
145 
146 			if (size == 16) { /* lvx */
147 				vcpu->arch.mmio_copy_type =
148 						KVMPPC_VMX_COPY_DWORD;
149 			} else if (size == 4) { /* lvewx  */
150 				vcpu->arch.mmio_copy_type =
151 						KVMPPC_VMX_COPY_WORD;
152 			} else if (size == 2) { /* lvehx  */
153 				vcpu->arch.mmio_copy_type =
154 						KVMPPC_VMX_COPY_HWORD;
155 			} else if (size == 1) { /* lvebx  */
156 				vcpu->arch.mmio_copy_type =
157 						KVMPPC_VMX_COPY_BYTE;
158 			} else
159 				break;
160 
161 			vcpu->arch.mmio_vmx_offset =
162 				(vcpu->arch.vaddr_accessed & 0xf)/size;
163 
164 			if (size == 16) {
165 				vcpu->arch.mmio_vmx_copy_nums = 2;
166 				emulated = kvmppc_handle_vmx_load(vcpu,
167 						KVM_MMIO_REG_VMX|op.reg,
168 						8, 1);
169 			} else {
170 				vcpu->arch.mmio_vmx_copy_nums = 1;
171 				emulated = kvmppc_handle_vmx_load(vcpu,
172 						KVM_MMIO_REG_VMX|op.reg,
173 						size, 1);
174 			}
175 			break;
176 #endif
177 #ifdef CONFIG_VSX
178 		case LOAD_VSX: {
179 			int io_size_each;
180 
181 			if (op.vsx_flags & VSX_CHECK_VEC) {
182 				if (kvmppc_check_altivec_disabled(vcpu))
183 					return EMULATE_DONE;
184 			} else {
185 				if (kvmppc_check_vsx_disabled(vcpu))
186 					return EMULATE_DONE;
187 			}
188 
189 			if (op.vsx_flags & VSX_FPCONV)
190 				vcpu->arch.mmio_sp64_extend = 1;
191 
192 			if (op.element_size == 8)  {
193 				if (op.vsx_flags & VSX_SPLAT)
194 					vcpu->arch.mmio_copy_type =
195 						KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
196 				else
197 					vcpu->arch.mmio_copy_type =
198 						KVMPPC_VSX_COPY_DWORD;
199 			} else if (op.element_size == 4) {
200 				if (op.vsx_flags & VSX_SPLAT)
201 					vcpu->arch.mmio_copy_type =
202 						KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
203 				else
204 					vcpu->arch.mmio_copy_type =
205 						KVMPPC_VSX_COPY_WORD;
206 			} else
207 				break;
208 
209 			if (size < op.element_size) {
210 				/* precision convert case: lxsspx, etc */
211 				vcpu->arch.mmio_vsx_copy_nums = 1;
212 				io_size_each = size;
213 			} else { /* lxvw4x, lxvd2x, etc */
214 				vcpu->arch.mmio_vsx_copy_nums =
215 					size/op.element_size;
216 				io_size_each = op.element_size;
217 			}
218 
219 			emulated = kvmppc_handle_vsx_load(vcpu,
220 					KVM_MMIO_REG_VSX|op.reg, io_size_each,
221 					1, op.type & SIGNEXT);
222 			break;
223 		}
224 #endif
225 		case STORE:
226 			/* if need byte reverse, op.val has been reversed by
227 			 * analyse_instr().
228 			 */
229 			emulated = kvmppc_handle_store(vcpu, op.val, size, 1);
230 
231 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
232 				kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
233 
234 			break;
235 #ifdef CONFIG_PPC_FPU
236 		case STORE_FP:
237 			if (kvmppc_check_fp_disabled(vcpu))
238 				return EMULATE_DONE;
239 
240 			/* The FP registers need to be flushed so that
241 			 * kvmppc_handle_store() can read actual FP vals
242 			 * from vcpu->arch.
243 			 */
244 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
245 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
246 						MSR_FP);
247 
248 			if (op.type & FPCONV)
249 				vcpu->arch.mmio_sp64_extend = 1;
250 
251 			emulated = kvmppc_handle_store(vcpu,
252 					VCPU_FPR(vcpu, op.reg), size, 1);
253 
254 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
255 				kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
256 
257 			break;
258 #endif
259 #ifdef CONFIG_ALTIVEC
260 		case STORE_VMX:
261 			if (kvmppc_check_altivec_disabled(vcpu))
262 				return EMULATE_DONE;
263 
264 			/* Hardware enforces alignment of VMX accesses. */
265 			vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
266 			vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
267 
268 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
269 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
270 						MSR_VEC);
271 			if (size == 16) { /* stvx */
272 				vcpu->arch.mmio_copy_type =
273 						KVMPPC_VMX_COPY_DWORD;
274 			} else if (size == 4) { /* stvewx  */
275 				vcpu->arch.mmio_copy_type =
276 						KVMPPC_VMX_COPY_WORD;
277 			} else if (size == 2) { /* stvehx  */
278 				vcpu->arch.mmio_copy_type =
279 						KVMPPC_VMX_COPY_HWORD;
280 			} else if (size == 1) { /* stvebx  */
281 				vcpu->arch.mmio_copy_type =
282 						KVMPPC_VMX_COPY_BYTE;
283 			} else
284 				break;
285 
286 			vcpu->arch.mmio_vmx_offset =
287 				(vcpu->arch.vaddr_accessed & 0xf)/size;
288 
289 			if (size == 16) {
290 				vcpu->arch.mmio_vmx_copy_nums = 2;
291 				emulated = kvmppc_handle_vmx_store(vcpu,
292 						op.reg, 8, 1);
293 			} else {
294 				vcpu->arch.mmio_vmx_copy_nums = 1;
295 				emulated = kvmppc_handle_vmx_store(vcpu,
296 						op.reg, size, 1);
297 			}
298 
299 			break;
300 #endif
301 #ifdef CONFIG_VSX
302 		case STORE_VSX: {
303 			int io_size_each;
304 
305 			if (op.vsx_flags & VSX_CHECK_VEC) {
306 				if (kvmppc_check_altivec_disabled(vcpu))
307 					return EMULATE_DONE;
308 			} else {
309 				if (kvmppc_check_vsx_disabled(vcpu))
310 					return EMULATE_DONE;
311 			}
312 
313 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
314 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
315 						MSR_VSX);
316 
317 			if (op.vsx_flags & VSX_FPCONV)
318 				vcpu->arch.mmio_sp64_extend = 1;
319 
320 			if (op.element_size == 8)
321 				vcpu->arch.mmio_copy_type =
322 						KVMPPC_VSX_COPY_DWORD;
323 			else if (op.element_size == 4)
324 				vcpu->arch.mmio_copy_type =
325 						KVMPPC_VSX_COPY_WORD;
326 			else
327 				break;
328 
329 			if (size < op.element_size) {
330 				/* precise conversion case, like stxsspx */
331 				vcpu->arch.mmio_vsx_copy_nums = 1;
332 				io_size_each = size;
333 			} else { /* stxvw4x, stxvd2x, etc */
334 				vcpu->arch.mmio_vsx_copy_nums =
335 						size/op.element_size;
336 				io_size_each = op.element_size;
337 			}
338 
339 			emulated = kvmppc_handle_vsx_store(vcpu,
340 					op.reg, io_size_each, 1);
341 			break;
342 		}
343 #endif
344 		case CACHEOP:
345 			/* Do nothing. The guest is performing dcbi because
346 			 * hardware DMA is not snooped by the dcache, but
347 			 * emulated DMA either goes through the dcache as
348 			 * normal writes, or the host kernel has handled dcache
349 			 * coherence.
350 			 */
351 			emulated = EMULATE_DONE;
352 			break;
353 		default:
354 			break;
355 		}
356 	}
357 
358 	if (emulated == EMULATE_FAIL) {
359 		advance = 0;
360 		kvmppc_core_queue_program(vcpu, 0);
361 	}
362 
363 	trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
364 
365 	/* Advance past emulated instruction. */
366 	if (advance)
367 		kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
368 
369 	return emulated;
370 }
371