1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Asm versions of Xen pv-ops, suitable for di
4 *
5 * We only bother with direct forms (ie, vcpu
6 * operations here; the indirect forms are bet
7 */
8
9 #include <asm/errno.h>
10 #include <asm/asm-offsets.h>
11 #include <asm/percpu.h>
12 #include <asm/processor-flags.h>
13 #include <asm/segment.h>
14 #include <asm/thread_info.h>
15 #include <asm/asm.h>
16 #include <asm/frame.h>
17 #include <asm/unwind_hints.h>
18
19 #include <xen/interface/xen.h>
20
21 #include <linux/init.h>
22 #include <linux/linkage.h>
23 #include <../entry/calling.h>
24
25 .pushsection .noinstr.text, "ax"
26 /*
27 * Disabling events is simply a matter of maki
28 * non-zero.
29 */
30 SYM_FUNC_START(xen_irq_disable_direct)
31 movb $1, PER_CPU_VAR(xen_vcpu_info + X
32 RET
33 SYM_FUNC_END(xen_irq_disable_direct)
34
35 /*
36 * Force an event check by making a hypercall,
37 * before making the call.
38 */
39 SYM_FUNC_START(check_events)
40 FRAME_BEGIN
41 push %rax
42 push %rcx
43 push %rdx
44 push %rsi
45 push %rdi
46 push %r8
47 push %r9
48 push %r10
49 push %r11
50 call xen_force_evtchn_callback
51 pop %r11
52 pop %r10
53 pop %r9
54 pop %r8
55 pop %rdi
56 pop %rsi
57 pop %rdx
58 pop %rcx
59 pop %rax
60 FRAME_END
61 RET
62 SYM_FUNC_END(check_events)
63
64 /*
65 * Enable events. This clears the event mask
66 * event status with one and operation. If th
67 * then enter the hypervisor to get them handl
68 */
69 SYM_FUNC_START(xen_irq_enable_direct)
70 FRAME_BEGIN
71 /* Unmask events */
72 movb $0, PER_CPU_VAR(xen_vcpu_info + X
73
74 /*
75 * Preempt here doesn't matter because
76 * pending interrupts. The pending ch
77 * on the wrong CPU, but that doesn't
78 */
79
80 /* Test for pending */
81 testb $0xff, PER_CPU_VAR(xen_vcpu_info
82 jz 1f
83
84 call check_events
85 1:
86 FRAME_END
87 RET
88 SYM_FUNC_END(xen_irq_enable_direct)
89
90 /*
91 * (xen_)save_fl is used to get the current in
92 * Callers expect the status to be in X86_EFLA
93 * may be set in the return value. We take ad
94 * making sure that X86_EFLAGS_IF has the righ
95 * in that byte are 0), but other bits in the
96 * undefined. We need to toggle the state of
97 * x86 use opposite senses (mask vs enable).
98 */
99 SYM_FUNC_START(xen_save_fl_direct)
100 testb $0xff, PER_CPU_VAR(xen_vcpu_info
101 setz %ah
102 addb %ah, %ah
103 RET
104 SYM_FUNC_END(xen_save_fl_direct)
105
106 SYM_FUNC_START(xen_read_cr2)
107 FRAME_BEGIN
108 _ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_
109 _ASM_MOV XEN_vcpu_info_arch_cr2(%_ASM_
110 FRAME_END
111 RET
112 SYM_FUNC_END(xen_read_cr2);
113
114 SYM_FUNC_START(xen_read_cr2_direct)
115 FRAME_BEGIN
116 _ASM_MOV PER_CPU_VAR(xen_vcpu_info + X
117 FRAME_END
118 RET
119 SYM_FUNC_END(xen_read_cr2_direct);
120 .popsection
121
122 .macro xen_pv_trap name
123 SYM_CODE_START(xen_\name)
124 UNWIND_HINT_ENTRY
125 ENDBR
126 pop %rcx
127 pop %r11
128 jmp \name
129 SYM_CODE_END(xen_\name)
130 _ASM_NOKPROBE(xen_\name)
131 .endm
132
133 xen_pv_trap asm_exc_divide_error
134 xen_pv_trap asm_xenpv_exc_debug
135 xen_pv_trap asm_exc_int3
136 xen_pv_trap asm_xenpv_exc_nmi
137 xen_pv_trap asm_exc_overflow
138 xen_pv_trap asm_exc_bounds
139 xen_pv_trap asm_exc_invalid_op
140 xen_pv_trap asm_exc_device_not_available
141 xen_pv_trap asm_xenpv_exc_double_fault
142 xen_pv_trap asm_exc_coproc_segment_overrun
143 xen_pv_trap asm_exc_invalid_tss
144 xen_pv_trap asm_exc_segment_not_present
145 xen_pv_trap asm_exc_stack_segment
146 xen_pv_trap asm_exc_general_protection
147 xen_pv_trap asm_exc_page_fault
148 xen_pv_trap asm_exc_spurious_interrupt_bug
149 xen_pv_trap asm_exc_coprocessor_error
150 xen_pv_trap asm_exc_alignment_check
151 #ifdef CONFIG_X86_CET
152 xen_pv_trap asm_exc_control_protection
153 #endif
154 #ifdef CONFIG_X86_MCE
155 xen_pv_trap asm_xenpv_exc_machine_check
156 #endif /* CONFIG_X86_MCE */
157 xen_pv_trap asm_exc_simd_coprocessor_error
158 #ifdef CONFIG_IA32_EMULATION
159 xen_pv_trap asm_int80_emulation
160 #endif
161 xen_pv_trap asm_exc_xen_unknown_trap
162 xen_pv_trap asm_exc_xen_hypervisor_callback
163
164 __INIT
165 SYM_CODE_START(xen_early_idt_handler_array)
166 i = 0
167 .rept NUM_EXCEPTION_VECTORS
168 UNWIND_HINT_UNDEFINED
169 ENDBR
170 pop %rcx
171 pop %r11
172 jmp early_idt_handler_array + i*EARLY_
173 i = i + 1
174 .fill xen_early_idt_handler_array + i*
175 .endr
176 SYM_CODE_END(xen_early_idt_handler_array)
177 __FINIT
178
179 hypercall_iret = hypercall_page + __HYPERVISOR
180 /*
181 * Xen64 iret frame:
182 *
183 * ss
184 * rsp
185 * rflags
186 * cs
187 * rip <-- standard iret fram
188 *
189 * flags
190 *
191 * rcx }
192 * r11 }<-- pushed by hyperca
193 * rsp->rax }
194 */
195 SYM_CODE_START(xen_iret)
196 UNWIND_HINT_UNDEFINED
197 ANNOTATE_NOENDBR
198 pushq $0
199 jmp hypercall_iret
200 SYM_CODE_END(xen_iret)
201
202 /*
203 * XEN pv doesn't use trampoline stack, PER_CP
204 * also the kernel stack. Reusing swapgs_rest
205 * in XEN pv would cause %rsp to move up to th
206 * leave the IRET frame below %rsp, which is d
207 * interrupts. And swapgs_restore_regs_and_ret
208 * frame at the same address is useless.
209 */
210 SYM_CODE_START(xenpv_restore_regs_and_return_t
211 UNWIND_HINT_REGS
212 POP_REGS
213
214 /* stackleak_erase() can work safely o
215 STACKLEAK_ERASE_NOCLOBBER
216
217 addq $8, %rsp /* skip regs->
218 jmp xen_iret
219 SYM_CODE_END(xenpv_restore_regs_and_return_to_
220
221 /*
222 * Xen handles syscall callbacks much like ord
223 * means we have:
224 * - kernel gs
225 * - kernel rsp
226 * - an iret-like stack frame on the stack (in
227 * ss
228 * rsp
229 * rflags
230 * cs
231 * rip
232 * r11
233 * rsp->rcx
234 */
235
236 /* Normal 64-bit system call target */
237 SYM_CODE_START(xen_entry_SYSCALL_64)
238 UNWIND_HINT_ENTRY
239 ENDBR
240 popq %rcx
241 popq %r11
242
243 /*
244 * Neither Xen nor the kernel really k
245 * CS were. The kernel expects __USER
246 * report those values even though Xen
247 */
248 movq $__USER_DS, 4*8(%rsp)
249 movq $__USER_CS, 1*8(%rsp)
250
251 jmp entry_SYSCALL_64_after_hwframe
252 SYM_CODE_END(xen_entry_SYSCALL_64)
253
254 #ifdef CONFIG_IA32_EMULATION
255
256 /* 32-bit compat syscall target */
257 SYM_CODE_START(xen_entry_SYSCALL_compat)
258 UNWIND_HINT_ENTRY
259 ENDBR
260 popq %rcx
261 popq %r11
262
263 /*
264 * Neither Xen nor the kernel really k
265 * CS were. The kernel expects __USER
266 * report those values even though Xen
267 */
268 movq $__USER_DS, 4*8(%rsp)
269 movq $__USER32_CS, 1*8(%rsp)
270
271 jmp entry_SYSCALL_compat_after_hwframe
272 SYM_CODE_END(xen_entry_SYSCALL_compat)
273
274 /* 32-bit compat sysenter target */
275 SYM_CODE_START(xen_entry_SYSENTER_compat)
276 UNWIND_HINT_ENTRY
277 ENDBR
278 /*
279 * NB: Xen is polite and clears TF fro
280 * that we don't need to guard against
281 */
282 popq %rcx
283 popq %r11
284
285 /*
286 * Neither Xen nor the kernel really k
287 * CS were. The kernel expects __USER
288 * report those values even though Xen
289 */
290 movq $__USER_DS, 4*8(%rsp)
291 movq $__USER32_CS, 1*8(%rsp)
292
293 jmp entry_SYSENTER_compat_after_hwfram
294 SYM_CODE_END(xen_entry_SYSENTER_compat)
295
296 #else /* !CONFIG_IA32_EMULATION */
297
298 SYM_CODE_START(xen_entry_SYSCALL_compat)
299 SYM_CODE_START(xen_entry_SYSENTER_compat)
300 UNWIND_HINT_ENTRY
301 ENDBR
302 lea 16(%rsp), %rsp /* strip %rcx,
303 mov $-ENOSYS, %rax
304 pushq $0
305 jmp hypercall_iret
306 SYM_CODE_END(xen_entry_SYSENTER_compat)
307 SYM_CODE_END(xen_entry_SYSCALL_compat)
308
309 #endif /* CONFIG_IA32_EMULATION */
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