Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86_tdx_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 tdx update from Dave Hansen:
"The original tdx hypercall assembly code took two flags in %RSI to
tweak its behavior at runtime. PeterZ recently axed one flag in commit
e80a48bade61 ("x86/tdx: Remove TDX_HCALL_ISSUE_STI").
Kill the other flag too and tweak the 'output' mode with an assembly
macro instead. This results in elimination of one push/pop pair and
overall easier to read assembly.
- Do conditional __tdx_hypercall() 'output' processing via an
assembly macro argument rather than a runtime register"
* tag 'x86_tdx_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tdx: Drop flags from __tdx_hypercall()
+51
-42
+2
-2
arch/x86/boot/compressed/tdx.c
+2
-2
arch/x86/boot/compressed/tdx.c
···
26
26
.r14 = port,
27
27
};
28
28
29
-
if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
29
+
if (__tdx_hypercall_ret(&args))
30
30
return UINT_MAX;
31
31
32
32
return args.r11;
···
43
43
.r15 = value,
44
44
};
45
45
46
-
__tdx_hypercall(&args, 0);
46
+
__tdx_hypercall(&args);
47
47
}
48
48
49
49
static inline u8 tdx_inb(u16 port)
+38
-28
arch/x86/coco/tdx/tdcall.S
+38
-28
arch/x86/coco/tdx/tdcall.S
···
85
85
SYM_FUNC_END(__tdx_module_call)
86
86
87
87
/*
88
-
* __tdx_hypercall() - Make hypercalls to a TDX VMM using TDVMCALL leaf
89
-
* of TDCALL instruction
88
+
* TDX_HYPERCALL - Make hypercalls to a TDX VMM using TDVMCALL leaf of TDCALL
89
+
* instruction
90
90
*
91
91
* Transforms values in function call argument struct tdx_hypercall_args @args
92
92
* into the TDCALL register ABI. After TDCALL operation, VMM output is saved
93
-
* back in @args.
93
+
* back in @args, if \ret is 1.
94
94
*
95
95
*-------------------------------------------------------------------------
96
96
* TD VMCALL ABI:
···
105
105
* specification. Non zero value indicates vendor
106
106
* specific ABI.
107
107
* R11 - VMCALL sub function number
108
-
* RBX, RBP, RDI, RSI - Used to pass VMCALL sub function specific arguments.
108
+
* RBX, RDX, RDI, RSI - Used to pass VMCALL sub function specific arguments.
109
109
* R8-R9, R12-R15 - Same as above.
110
110
*
111
111
* Output Registers:
112
112
*
113
113
* RAX - TDCALL instruction status (Not related to hypercall
114
114
* output).
115
-
* R10 - Hypercall output error code.
116
-
* R11-R15 - Hypercall sub function specific output values.
115
+
* RBX, RDX, RDI, RSI - Hypercall sub function specific output values.
116
+
* R8-R15 - Same as above.
117
117
*
118
-
*-------------------------------------------------------------------------
119
-
*
120
-
* __tdx_hypercall() function ABI:
121
-
*
122
-
* @args (RDI) - struct tdx_hypercall_args for input and output
123
-
* @flags (RSI) - TDX_HCALL_* flags
124
-
*
125
-
* On successful completion, return the hypercall error code.
126
118
*/
127
-
SYM_FUNC_START(__tdx_hypercall)
119
+
.macro TDX_HYPERCALL ret:req
128
120
FRAME_BEGIN
129
121
130
122
/* Save callee-saved GPRs as mandated by the x86_64 ABI */
···
126
134
push %r12
127
135
push %rbx
128
136
129
-
/* Free RDI and RSI to be used as TDVMCALL arguments */
137
+
/* Free RDI to be used as TDVMCALL arguments */
130
138
movq %rdi, %rax
131
-
push %rsi
132
139
133
140
/* Copy hypercall registers from arg struct: */
134
141
movq TDX_HYPERCALL_r8(%rax), %r8
···
162
171
* and are handled by callers.
163
172
*/
164
173
testq %rax, %rax
165
-
jne .Lpanic
174
+
jne .Lpanic\@
166
175
167
176
pop %rax
168
177
169
-
/* Copy hypercall result registers to arg struct if needed */
170
-
testq $TDX_HCALL_HAS_OUTPUT, (%rsp)
171
-
jz .Lout
172
-
178
+
.if \ret
173
179
movq %r8, TDX_HYPERCALL_r8(%rax)
174
180
movq %r9, TDX_HYPERCALL_r9(%rax)
175
181
movq %r10, TDX_HYPERCALL_r10(%rax)
···
179
191
movq %rsi, TDX_HYPERCALL_rsi(%rax)
180
192
movq %rbx, TDX_HYPERCALL_rbx(%rax)
181
193
movq %rdx, TDX_HYPERCALL_rdx(%rax)
182
-
.Lout:
194
+
.endif
195
+
183
196
/* TDVMCALL leaf return code is in R10 */
184
197
movq %r10, %rax
185
198
···
197
208
xor %rdi, %rdi
198
209
xor %rdx, %rdx
199
210
200
-
/* Remove TDX_HCALL_* flags from the stack */
201
-
pop %rsi
202
-
203
211
/* Restore callee-saved GPRs as mandated by the x86_64 ABI */
204
212
pop %rbx
205
213
pop %r12
···
207
221
FRAME_END
208
222
209
223
RET
210
-
.Lpanic:
224
+
.Lpanic\@:
211
225
call __tdx_hypercall_failed
212
226
/* __tdx_hypercall_failed never returns */
213
227
REACHABLE
214
-
jmp .Lpanic
228
+
jmp .Lpanic\@
229
+
.endm
230
+
231
+
/*
232
+
*
233
+
* __tdx_hypercall() function ABI:
234
+
*
235
+
* @args (RDI) - struct tdx_hypercall_args for input
236
+
*
237
+
* On successful completion, return the hypercall error code.
238
+
*/
239
+
SYM_FUNC_START(__tdx_hypercall)
240
+
TDX_HYPERCALL ret=0
215
241
SYM_FUNC_END(__tdx_hypercall)
242
+
243
+
/*
244
+
*
245
+
* __tdx_hypercall_ret() function ABI:
246
+
*
247
+
* @args (RDI) - struct tdx_hypercall_args for input and output
248
+
*
249
+
* On successful completion, return the hypercall error code.
250
+
*/
251
+
SYM_FUNC_START(__tdx_hypercall_ret)
252
+
TDX_HYPERCALL ret=1
253
+
SYM_FUNC_END(__tdx_hypercall_ret)
+9
-9
arch/x86/coco/tdx/tdx.c
+9
-9
arch/x86/coco/tdx/tdx.c
···
66
66
.r15 = r15,
67
67
};
68
68
69
-
return __tdx_hypercall(&args, 0);
69
+
return __tdx_hypercall(&args);
70
70
}
71
71
72
72
/* Called from __tdx_hypercall() for unrecoverable failure */
···
99
99
.r14 = p4,
100
100
};
101
101
102
-
return __tdx_hypercall(&args, 0);
102
+
return __tdx_hypercall(&args);
103
103
}
104
104
EXPORT_SYMBOL_GPL(tdx_kvm_hypercall);
105
105
#endif
···
179
179
* happens to return.
180
180
*/
181
181
while (1)
182
-
__tdx_hypercall(&args, 0);
182
+
__tdx_hypercall(&args);
183
183
}
184
184
185
185
static void tdx_parse_tdinfo(u64 *cc_mask)
···
289
289
* can keep the vCPU in virtual HLT, even if an IRQ is
290
290
* pending, without hanging/breaking the guest.
291
291
*/
292
-
return __tdx_hypercall(&args, 0);
292
+
return __tdx_hypercall(&args);
293
293
}
294
294
295
295
static int handle_halt(struct ve_info *ve)
···
326
326
* can be found in TDX Guest-Host-Communication Interface
327
327
* (GHCI), section titled "TDG.VP.VMCALL<Instruction.RDMSR>".
328
328
*/
329
-
if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
329
+
if (__tdx_hypercall_ret(&args))
330
330
return -EIO;
331
331
332
332
regs->ax = lower_32_bits(args.r11);
···
348
348
* can be found in TDX Guest-Host-Communication Interface
349
349
* (GHCI) section titled "TDG.VP.VMCALL<Instruction.WRMSR>".
350
350
*/
351
-
if (__tdx_hypercall(&args, 0))
351
+
if (__tdx_hypercall(&args))
352
352
return -EIO;
353
353
354
354
return ve_instr_len(ve);
···
380
380
* ABI can be found in TDX Guest-Host-Communication Interface
381
381
* (GHCI), section titled "VP.VMCALL<Instruction.CPUID>".
382
382
*/
383
-
if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
383
+
if (__tdx_hypercall_ret(&args))
384
384
return -EIO;
385
385
386
386
/*
···
407
407
.r15 = *val,
408
408
};
409
409
410
-
if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
410
+
if (__tdx_hypercall_ret(&args))
411
411
return false;
412
412
*val = args.r11;
413
413
return true;
···
541
541
* in TDX Guest-Host-Communication Interface (GHCI) section titled
542
542
* "TDG.VP.VMCALL<Instruction.IO>".
543
543
*/
544
-
success = !__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT);
544
+
success = !__tdx_hypercall_ret(&args);
545
545
546
546
/* Update part of the register affected by the emulated instruction */
547
547
regs->ax &= ~mask;