xref: /linux/arch/powerpc/kvm/emulate_loadstore.c (revision 06d07429858317ded2db7986113a9e0129cd599b)
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
kvmppc_check_fp_disabled(struct kvm_vcpu * vcpu)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, kvmppc_get_msr(vcpu) & SRR1_PREFIXED);
32 		return true;
33 	}
34 
35 	return false;
36 }
37 #endif /* CONFIG_PPC_FPU */
38 
39 #ifdef CONFIG_VSX
kvmppc_check_vsx_disabled(struct kvm_vcpu * vcpu)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, kvmppc_get_msr(vcpu) & SRR1_PREFIXED);
44 		return true;
45 	}
46 
47 	return false;
48 }
49 #endif /* CONFIG_VSX */
50 
51 #ifdef CONFIG_ALTIVEC
kvmppc_check_altivec_disabled(struct kvm_vcpu * vcpu)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, kvmppc_get_msr(vcpu) & SRR1_PREFIXED);
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  */
kvmppc_emulate_loadstore(struct kvm_vcpu * vcpu)72 int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
73 {
74 	ppc_inst_t inst;
75 	enum emulation_result emulated = EMULATE_FAIL;
76 	struct instruction_op op;
77 
78 	/* this default type might be overwritten by subcategories */
79 	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
80 
81 	emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
82 	if (emulated != EMULATE_DONE)
83 		return emulated;
84 
85 	vcpu->arch.mmio_vsx_copy_nums = 0;
86 	vcpu->arch.mmio_vsx_offset = 0;
87 	vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
88 	vcpu->arch.mmio_sp64_extend = 0;
89 	vcpu->arch.mmio_sign_extend = 0;
90 	vcpu->arch.mmio_vmx_copy_nums = 0;
91 	vcpu->arch.mmio_vmx_offset = 0;
92 	vcpu->arch.mmio_host_swabbed = 0;
93 
94 	emulated = EMULATE_FAIL;
95 	vcpu->arch.regs.msr = kvmppc_get_msr(vcpu);
96 	if (analyse_instr(&op, &vcpu->arch.regs, inst) == 0) {
97 		int type = op.type & INSTR_TYPE_MASK;
98 		int size = GETSIZE(op.type);
99 
100 		vcpu->mmio_is_write = OP_IS_STORE(type);
101 
102 		switch (type) {
103 		case LOAD:  {
104 			int instr_byte_swap = op.type & BYTEREV;
105 
106 			if (op.type & SIGNEXT)
107 				emulated = kvmppc_handle_loads(vcpu,
108 						op.reg, size, !instr_byte_swap);
109 			else
110 				emulated = kvmppc_handle_load(vcpu,
111 						op.reg, size, !instr_byte_swap);
112 
113 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
114 				kvmppc_set_gpr(vcpu, op.update_reg, vcpu->arch.vaddr_accessed);
115 
116 			break;
117 		}
118 #ifdef CONFIG_PPC_FPU
119 		case LOAD_FP:
120 			if (kvmppc_check_fp_disabled(vcpu))
121 				return EMULATE_DONE;
122 
123 			if (op.type & FPCONV)
124 				vcpu->arch.mmio_sp64_extend = 1;
125 
126 			if (op.type & SIGNEXT)
127 				emulated = kvmppc_handle_loads(vcpu,
128 					     KVM_MMIO_REG_FPR|op.reg, size, 1);
129 			else
130 				emulated = kvmppc_handle_load(vcpu,
131 					     KVM_MMIO_REG_FPR|op.reg, size, 1);
132 
133 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
134 				kvmppc_set_gpr(vcpu, op.update_reg, vcpu->arch.vaddr_accessed);
135 
136 			break;
137 #endif
138 #ifdef CONFIG_ALTIVEC
139 		case LOAD_VMX:
140 			if (kvmppc_check_altivec_disabled(vcpu))
141 				return EMULATE_DONE;
142 
143 			/* Hardware enforces alignment of VMX accesses */
144 			vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
145 			vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
146 
147 			if (size == 16) { /* lvx */
148 				vcpu->arch.mmio_copy_type =
149 						KVMPPC_VMX_COPY_DWORD;
150 			} else if (size == 4) { /* lvewx  */
151 				vcpu->arch.mmio_copy_type =
152 						KVMPPC_VMX_COPY_WORD;
153 			} else if (size == 2) { /* lvehx  */
154 				vcpu->arch.mmio_copy_type =
155 						KVMPPC_VMX_COPY_HWORD;
156 			} else if (size == 1) { /* lvebx  */
157 				vcpu->arch.mmio_copy_type =
158 						KVMPPC_VMX_COPY_BYTE;
159 			} else
160 				break;
161 
162 			vcpu->arch.mmio_vmx_offset =
163 				(vcpu->arch.vaddr_accessed & 0xf)/size;
164 
165 			if (size == 16) {
166 				vcpu->arch.mmio_vmx_copy_nums = 2;
167 				emulated = kvmppc_handle_vmx_load(vcpu,
168 						KVM_MMIO_REG_VMX|op.reg,
169 						8, 1);
170 			} else {
171 				vcpu->arch.mmio_vmx_copy_nums = 1;
172 				emulated = kvmppc_handle_vmx_load(vcpu,
173 						KVM_MMIO_REG_VMX|op.reg,
174 						size, 1);
175 			}
176 			break;
177 #endif
178 #ifdef CONFIG_VSX
179 		case LOAD_VSX: {
180 			int io_size_each;
181 
182 			if (op.vsx_flags & VSX_CHECK_VEC) {
183 				if (kvmppc_check_altivec_disabled(vcpu))
184 					return EMULATE_DONE;
185 			} else {
186 				if (kvmppc_check_vsx_disabled(vcpu))
187 					return EMULATE_DONE;
188 			}
189 
190 			if (op.vsx_flags & VSX_FPCONV)
191 				vcpu->arch.mmio_sp64_extend = 1;
192 
193 			if (op.element_size == 8)  {
194 				if (op.vsx_flags & VSX_SPLAT)
195 					vcpu->arch.mmio_copy_type =
196 						KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
197 				else
198 					vcpu->arch.mmio_copy_type =
199 						KVMPPC_VSX_COPY_DWORD;
200 			} else if (op.element_size == 4) {
201 				if (op.vsx_flags & VSX_SPLAT)
202 					vcpu->arch.mmio_copy_type =
203 						KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
204 				else
205 					vcpu->arch.mmio_copy_type =
206 						KVMPPC_VSX_COPY_WORD;
207 			} else
208 				break;
209 
210 			if (size < op.element_size) {
211 				/* precision convert case: lxsspx, etc */
212 				vcpu->arch.mmio_vsx_copy_nums = 1;
213 				io_size_each = size;
214 			} else { /* lxvw4x, lxvd2x, etc */
215 				vcpu->arch.mmio_vsx_copy_nums =
216 					size/op.element_size;
217 				io_size_each = op.element_size;
218 			}
219 
220 			emulated = kvmppc_handle_vsx_load(vcpu,
221 					KVM_MMIO_REG_VSX|op.reg, io_size_each,
222 					1, op.type & SIGNEXT);
223 			break;
224 		}
225 #endif
226 		case STORE: {
227 			int instr_byte_swap = op.type & BYTEREV;
228 
229 			emulated = kvmppc_handle_store(vcpu, kvmppc_get_gpr(vcpu, op.reg),
230 						       size, !instr_byte_swap);
231 
232 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
233 				kvmppc_set_gpr(vcpu, op.update_reg, vcpu->arch.vaddr_accessed);
234 
235 			break;
236 		}
237 #ifdef CONFIG_PPC_FPU
238 		case STORE_FP:
239 			if (kvmppc_check_fp_disabled(vcpu))
240 				return EMULATE_DONE;
241 
242 			/* The FP registers need to be flushed so that
243 			 * kvmppc_handle_store() can read actual FP vals
244 			 * from vcpu->arch.
245 			 */
246 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
247 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
248 						MSR_FP);
249 
250 			if (op.type & FPCONV)
251 				vcpu->arch.mmio_sp64_extend = 1;
252 
253 			emulated = kvmppc_handle_store(vcpu,
254 					kvmppc_get_fpr(vcpu, op.reg), size, 1);
255 
256 			if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
257 				kvmppc_set_gpr(vcpu, op.update_reg, vcpu->arch.vaddr_accessed);
258 
259 			break;
260 #endif
261 #ifdef CONFIG_ALTIVEC
262 		case STORE_VMX:
263 			if (kvmppc_check_altivec_disabled(vcpu))
264 				return EMULATE_DONE;
265 
266 			/* Hardware enforces alignment of VMX accesses. */
267 			vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
268 			vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
269 
270 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
271 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
272 						MSR_VEC);
273 			if (size == 16) { /* stvx */
274 				vcpu->arch.mmio_copy_type =
275 						KVMPPC_VMX_COPY_DWORD;
276 			} else if (size == 4) { /* stvewx  */
277 				vcpu->arch.mmio_copy_type =
278 						KVMPPC_VMX_COPY_WORD;
279 			} else if (size == 2) { /* stvehx  */
280 				vcpu->arch.mmio_copy_type =
281 						KVMPPC_VMX_COPY_HWORD;
282 			} else if (size == 1) { /* stvebx  */
283 				vcpu->arch.mmio_copy_type =
284 						KVMPPC_VMX_COPY_BYTE;
285 			} else
286 				break;
287 
288 			vcpu->arch.mmio_vmx_offset =
289 				(vcpu->arch.vaddr_accessed & 0xf)/size;
290 
291 			if (size == 16) {
292 				vcpu->arch.mmio_vmx_copy_nums = 2;
293 				emulated = kvmppc_handle_vmx_store(vcpu,
294 						op.reg, 8, 1);
295 			} else {
296 				vcpu->arch.mmio_vmx_copy_nums = 1;
297 				emulated = kvmppc_handle_vmx_store(vcpu,
298 						op.reg, size, 1);
299 			}
300 
301 			break;
302 #endif
303 #ifdef CONFIG_VSX
304 		case STORE_VSX: {
305 			int io_size_each;
306 
307 			if (op.vsx_flags & VSX_CHECK_VEC) {
308 				if (kvmppc_check_altivec_disabled(vcpu))
309 					return EMULATE_DONE;
310 			} else {
311 				if (kvmppc_check_vsx_disabled(vcpu))
312 					return EMULATE_DONE;
313 			}
314 
315 			if (vcpu->kvm->arch.kvm_ops->giveup_ext)
316 				vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
317 						MSR_VSX);
318 
319 			if (op.vsx_flags & VSX_FPCONV)
320 				vcpu->arch.mmio_sp64_extend = 1;
321 
322 			if (op.element_size == 8)
323 				vcpu->arch.mmio_copy_type =
324 						KVMPPC_VSX_COPY_DWORD;
325 			else if (op.element_size == 4)
326 				vcpu->arch.mmio_copy_type =
327 						KVMPPC_VSX_COPY_WORD;
328 			else
329 				break;
330 
331 			if (size < op.element_size) {
332 				/* precise conversion case, like stxsspx */
333 				vcpu->arch.mmio_vsx_copy_nums = 1;
334 				io_size_each = size;
335 			} else { /* stxvw4x, stxvd2x, etc */
336 				vcpu->arch.mmio_vsx_copy_nums =
337 						size/op.element_size;
338 				io_size_each = op.element_size;
339 			}
340 
341 			emulated = kvmppc_handle_vsx_store(vcpu,
342 					op.reg, io_size_each, 1);
343 			break;
344 		}
345 #endif
346 		case CACHEOP:
347 			/* Do nothing. The guest is performing dcbi because
348 			 * hardware DMA is not snooped by the dcache, but
349 			 * emulated DMA either goes through the dcache as
350 			 * normal writes, or the host kernel has handled dcache
351 			 * coherence.
352 			 */
353 			emulated = EMULATE_DONE;
354 			break;
355 		default:
356 			break;
357 		}
358 	}
359 
360 	trace_kvm_ppc_instr(ppc_inst_val(inst), kvmppc_get_pc(vcpu), emulated);
361 
362 	/* Advance past emulated instruction. */
363 	if (emulated != EMULATE_FAIL)
364 		kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + ppc_inst_len(inst));
365 
366 	return emulated;
367 }
368