xref: /openbmc/linux/arch/x86/kvm/vmx/vmx_ops.h (revision be2b81b5)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __KVM_X86_VMX_INSN_H
3 #define __KVM_X86_VMX_INSN_H
4 
5 #include <linux/nospec.h>
6 
7 #include <asm/vmx.h>
8 
9 #include "hyperv.h"
10 #include "vmcs.h"
11 #include "../x86.h"
12 
13 void vmread_error(unsigned long field, bool fault);
14 void vmwrite_error(unsigned long field, unsigned long value);
15 void vmclear_error(struct vmcs *vmcs, u64 phys_addr);
16 void vmptrld_error(struct vmcs *vmcs, u64 phys_addr);
17 void invvpid_error(unsigned long ext, u16 vpid, gva_t gva);
18 void invept_error(unsigned long ext, u64 eptp, gpa_t gpa);
19 
20 #ifndef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
21 /*
22  * The VMREAD error trampoline _always_ uses the stack to pass parameters, even
23  * for 64-bit targets.  Preserving all registers allows the VMREAD inline asm
24  * blob to avoid clobbering GPRs, which in turn allows the compiler to better
25  * optimize sequences of VMREADs.
26  *
27  * Declare the trampoline as an opaque label as it's not safe to call from C
28  * code; there is no way to tell the compiler to pass params on the stack for
29  * 64-bit targets.
30  *
31  * void vmread_error_trampoline(unsigned long field, bool fault);
32  */
33 extern unsigned long vmread_error_trampoline;
34 #endif
35 
36 static __always_inline void vmcs_check16(unsigned long field)
37 {
38 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2000,
39 			 "16-bit accessor invalid for 64-bit field");
40 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2001,
41 			 "16-bit accessor invalid for 64-bit high field");
42 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x4000,
43 			 "16-bit accessor invalid for 32-bit high field");
44 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x6000,
45 			 "16-bit accessor invalid for natural width field");
46 }
47 
48 static __always_inline void vmcs_check32(unsigned long field)
49 {
50 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0,
51 			 "32-bit accessor invalid for 16-bit field");
52 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2000,
53 			 "32-bit accessor invalid for 64-bit field");
54 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2001,
55 			 "32-bit accessor invalid for 64-bit high field");
56 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x6000,
57 			 "32-bit accessor invalid for natural width field");
58 }
59 
60 static __always_inline void vmcs_check64(unsigned long field)
61 {
62 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0,
63 			 "64-bit accessor invalid for 16-bit field");
64 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2001,
65 			 "64-bit accessor invalid for 64-bit high field");
66 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x4000,
67 			 "64-bit accessor invalid for 32-bit field");
68 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x6000,
69 			 "64-bit accessor invalid for natural width field");
70 }
71 
72 static __always_inline void vmcs_checkl(unsigned long field)
73 {
74 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0,
75 			 "Natural width accessor invalid for 16-bit field");
76 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2000,
77 			 "Natural width accessor invalid for 64-bit field");
78 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2001,
79 			 "Natural width accessor invalid for 64-bit high field");
80 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x4000,
81 			 "Natural width accessor invalid for 32-bit field");
82 }
83 
84 static __always_inline unsigned long __vmcs_readl(unsigned long field)
85 {
86 	unsigned long value;
87 
88 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
89 
90 	asm_volatile_goto("1: vmread %[field], %[output]\n\t"
91 			  "jna %l[do_fail]\n\t"
92 
93 			  _ASM_EXTABLE(1b, %l[do_exception])
94 
95 			  : [output] "=r" (value)
96 			  : [field] "r" (field)
97 			  : "cc"
98 			  : do_fail, do_exception);
99 
100 	return value;
101 
102 do_fail:
103 	WARN_ONCE(1, "kvm: vmread failed: field=%lx\n", field);
104 	pr_warn_ratelimited("kvm: vmread failed: field=%lx\n", field);
105 	return 0;
106 
107 do_exception:
108 	kvm_spurious_fault();
109 	return 0;
110 
111 #else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
112 
113 	asm volatile("1: vmread %2, %1\n\t"
114 		     ".byte 0x3e\n\t" /* branch taken hint */
115 		     "ja 3f\n\t"
116 
117 		     /*
118 		      * VMREAD failed.  Push '0' for @fault, push the failing
119 		      * @field, and bounce through the trampoline to preserve
120 		      * volatile registers.
121 		      */
122 		     "xorl %k1, %k1\n\t"
123 		     "2:\n\t"
124 		     "push %1\n\t"
125 		     "push %2\n\t"
126 		     "call vmread_error_trampoline\n\t"
127 
128 		     /*
129 		      * Unwind the stack.  Note, the trampoline zeros out the
130 		      * memory for @fault so that the result is '0' on error.
131 		      */
132 		     "pop %2\n\t"
133 		     "pop %1\n\t"
134 		     "3:\n\t"
135 
136 		     /* VMREAD faulted.  As above, except push '1' for @fault. */
137 		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_ONE_REG, %1)
138 
139 		     : ASM_CALL_CONSTRAINT, "=&r"(value) : "r"(field) : "cc");
140 	return value;
141 
142 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
143 }
144 
145 static __always_inline u16 vmcs_read16(unsigned long field)
146 {
147 	vmcs_check16(field);
148 	if (static_branch_unlikely(&enable_evmcs))
149 		return evmcs_read16(field);
150 	return __vmcs_readl(field);
151 }
152 
153 static __always_inline u32 vmcs_read32(unsigned long field)
154 {
155 	vmcs_check32(field);
156 	if (static_branch_unlikely(&enable_evmcs))
157 		return evmcs_read32(field);
158 	return __vmcs_readl(field);
159 }
160 
161 static __always_inline u64 vmcs_read64(unsigned long field)
162 {
163 	vmcs_check64(field);
164 	if (static_branch_unlikely(&enable_evmcs))
165 		return evmcs_read64(field);
166 #ifdef CONFIG_X86_64
167 	return __vmcs_readl(field);
168 #else
169 	return __vmcs_readl(field) | ((u64)__vmcs_readl(field+1) << 32);
170 #endif
171 }
172 
173 static __always_inline unsigned long vmcs_readl(unsigned long field)
174 {
175 	vmcs_checkl(field);
176 	if (static_branch_unlikely(&enable_evmcs))
177 		return evmcs_read64(field);
178 	return __vmcs_readl(field);
179 }
180 
181 #define vmx_asm1(insn, op1, error_args...)				\
182 do {									\
183 	asm_volatile_goto("1: " __stringify(insn) " %0\n\t"		\
184 			  ".byte 0x2e\n\t" /* branch not taken hint */	\
185 			  "jna %l[error]\n\t"				\
186 			  _ASM_EXTABLE(1b, %l[fault])			\
187 			  : : op1 : "cc" : error, fault);		\
188 	return;								\
189 error:									\
190 	instrumentation_begin();					\
191 	insn##_error(error_args);					\
192 	instrumentation_end();						\
193 	return;								\
194 fault:									\
195 	kvm_spurious_fault();						\
196 } while (0)
197 
198 #define vmx_asm2(insn, op1, op2, error_args...)				\
199 do {									\
200 	asm_volatile_goto("1: "  __stringify(insn) " %1, %0\n\t"	\
201 			  ".byte 0x2e\n\t" /* branch not taken hint */	\
202 			  "jna %l[error]\n\t"				\
203 			  _ASM_EXTABLE(1b, %l[fault])			\
204 			  : : op1, op2 : "cc" : error, fault);		\
205 	return;								\
206 error:									\
207 	instrumentation_begin();					\
208 	insn##_error(error_args);					\
209 	instrumentation_end();						\
210 	return;								\
211 fault:									\
212 	kvm_spurious_fault();						\
213 } while (0)
214 
215 static __always_inline void __vmcs_writel(unsigned long field, unsigned long value)
216 {
217 	vmx_asm2(vmwrite, "r"(field), "rm"(value), field, value);
218 }
219 
220 static __always_inline void vmcs_write16(unsigned long field, u16 value)
221 {
222 	vmcs_check16(field);
223 	if (static_branch_unlikely(&enable_evmcs))
224 		return evmcs_write16(field, value);
225 
226 	__vmcs_writel(field, value);
227 }
228 
229 static __always_inline void vmcs_write32(unsigned long field, u32 value)
230 {
231 	vmcs_check32(field);
232 	if (static_branch_unlikely(&enable_evmcs))
233 		return evmcs_write32(field, value);
234 
235 	__vmcs_writel(field, value);
236 }
237 
238 static __always_inline void vmcs_write64(unsigned long field, u64 value)
239 {
240 	vmcs_check64(field);
241 	if (static_branch_unlikely(&enable_evmcs))
242 		return evmcs_write64(field, value);
243 
244 	__vmcs_writel(field, value);
245 #ifndef CONFIG_X86_64
246 	__vmcs_writel(field+1, value >> 32);
247 #endif
248 }
249 
250 static __always_inline void vmcs_writel(unsigned long field, unsigned long value)
251 {
252 	vmcs_checkl(field);
253 	if (static_branch_unlikely(&enable_evmcs))
254 		return evmcs_write64(field, value);
255 
256 	__vmcs_writel(field, value);
257 }
258 
259 static __always_inline void vmcs_clear_bits(unsigned long field, u32 mask)
260 {
261 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x2000,
262 			 "vmcs_clear_bits does not support 64-bit fields");
263 	if (static_branch_unlikely(&enable_evmcs))
264 		return evmcs_write32(field, evmcs_read32(field) & ~mask);
265 
266 	__vmcs_writel(field, __vmcs_readl(field) & ~mask);
267 }
268 
269 static __always_inline void vmcs_set_bits(unsigned long field, u32 mask)
270 {
271 	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x2000,
272 			 "vmcs_set_bits does not support 64-bit fields");
273 	if (static_branch_unlikely(&enable_evmcs))
274 		return evmcs_write32(field, evmcs_read32(field) | mask);
275 
276 	__vmcs_writel(field, __vmcs_readl(field) | mask);
277 }
278 
279 static inline void vmcs_clear(struct vmcs *vmcs)
280 {
281 	u64 phys_addr = __pa(vmcs);
282 
283 	vmx_asm1(vmclear, "m"(phys_addr), vmcs, phys_addr);
284 }
285 
286 static inline void vmcs_load(struct vmcs *vmcs)
287 {
288 	u64 phys_addr = __pa(vmcs);
289 
290 	if (static_branch_unlikely(&enable_evmcs))
291 		return evmcs_load(phys_addr);
292 
293 	vmx_asm1(vmptrld, "m"(phys_addr), vmcs, phys_addr);
294 }
295 
296 static inline void __invvpid(unsigned long ext, u16 vpid, gva_t gva)
297 {
298 	struct {
299 		u64 vpid : 16;
300 		u64 rsvd : 48;
301 		u64 gva;
302 	} operand = { vpid, 0, gva };
303 
304 	vmx_asm2(invvpid, "r"(ext), "m"(operand), ext, vpid, gva);
305 }
306 
307 static inline void __invept(unsigned long ext, u64 eptp, gpa_t gpa)
308 {
309 	struct {
310 		u64 eptp, gpa;
311 	} operand = {eptp, gpa};
312 
313 	vmx_asm2(invept, "r"(ext), "m"(operand), ext, eptp, gpa);
314 }
315 
316 static inline void vpid_sync_vcpu_single(int vpid)
317 {
318 	if (vpid == 0)
319 		return;
320 
321 	__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vpid, 0);
322 }
323 
324 static inline void vpid_sync_vcpu_global(void)
325 {
326 	__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
327 }
328 
329 static inline void vpid_sync_context(int vpid)
330 {
331 	if (cpu_has_vmx_invvpid_single())
332 		vpid_sync_vcpu_single(vpid);
333 	else if (vpid != 0)
334 		vpid_sync_vcpu_global();
335 }
336 
337 static inline void vpid_sync_vcpu_addr(int vpid, gva_t addr)
338 {
339 	if (vpid == 0)
340 		return;
341 
342 	if (cpu_has_vmx_invvpid_individual_addr())
343 		__invvpid(VMX_VPID_EXTENT_INDIVIDUAL_ADDR, vpid, addr);
344 	else
345 		vpid_sync_context(vpid);
346 }
347 
348 static inline void ept_sync_global(void)
349 {
350 	__invept(VMX_EPT_EXTENT_GLOBAL, 0, 0);
351 }
352 
353 static inline void ept_sync_context(u64 eptp)
354 {
355 	if (cpu_has_vmx_invept_context())
356 		__invept(VMX_EPT_EXTENT_CONTEXT, eptp, 0);
357 	else
358 		ept_sync_global();
359 }
360 
361 #endif /* __KVM_X86_VMX_INSN_H */
362