1 /*
2 * VMware Detection code.
3 *
4 * Copyright (C) 2008, VMware, Inc.
5 * Author : Alok N Kataria <akataria@vmware.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
15 * NON INFRINGEMENT. See the GNU General Public License for more
16 * details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 */
23
24 #include <linux/dmi.h>
25 #include <linux/init.h>
26 #include <linux/export.h>
27 #include <linux/clocksource.h>
28 #include <linux/cpu.h>
29 #include <linux/reboot.h>
30 #include <linux/static_call.h>
31 #include <asm/div64.h>
32 #include <asm/x86_init.h>
33 #include <asm/hypervisor.h>
34 #include <asm/timer.h>
35 #include <asm/apic.h>
36 #include <asm/vmware.h>
37 #include <asm/svm.h>
38
39 #undef pr_fmt
40 #define pr_fmt(fmt) "vmware: " fmt
41
42 #define CPUID_VMWARE_INFO_LEAF 0x40000000
43 #define CPUID_VMWARE_FEATURES_LEAF 0x40000010
44
45 #define GETVCPU_INFO_LEGACY_X2APIC BIT(3)
46 #define GETVCPU_INFO_VCPU_RESERVED BIT(31)
47
48 #define STEALCLOCK_NOT_AVAILABLE (-1)
49 #define STEALCLOCK_DISABLED 0
50 #define STEALCLOCK_ENABLED 1
51
52 struct vmware_steal_time {
53 union {
54 u64 clock; /* stolen time counter in units of vtsc */
55 struct {
56 /* only for little-endian */
57 u32 clock_low;
58 u32 clock_high;
59 };
60 };
61 u64 reserved[7];
62 };
63
64 static unsigned long vmware_tsc_khz __ro_after_init;
65 static u8 vmware_hypercall_mode __ro_after_init;
66
67 unsigned long vmware_hypercall_slow(unsigned long cmd,
68 unsigned long in1, unsigned long in3,
69 unsigned long in4, unsigned long in5,
70 u32 *out1, u32 *out2, u32 *out3,
71 u32 *out4, u32 *out5)
72 {
73 unsigned long out0, rbx, rcx, rdx, rsi, rdi;
74
75 switch (vmware_hypercall_mode) {
76 case CPUID_VMWARE_FEATURES_ECX_VMCALL:
77 asm_inline volatile ("vmcall"
78 : "=a" (out0), "=b" (rbx), "=c" (rcx),
79 "=d" (rdx), "=S" (rsi), "=D" (rdi)
80 : "a" (VMWARE_HYPERVISOR_MAGIC),
81 "b" (in1),
82 "c" (cmd),
83 "d" (in3),
84 "S" (in4),
85 "D" (in5)
86 : "cc", "memory");
87 break;
88 case CPUID_VMWARE_FEATURES_ECX_VMMCALL:
89 asm_inline volatile ("vmmcall"
90 : "=a" (out0), "=b" (rbx), "=c" (rcx),
91 "=d" (rdx), "=S" (rsi), "=D" (rdi)
92 : "a" (VMWARE_HYPERVISOR_MAGIC),
93 "b" (in1),
94 "c" (cmd),
95 "d" (in3),
96 "S" (in4),
97 "D" (in5)
98 : "cc", "memory");
99 break;
100 default:
101 asm_inline volatile ("movw %[port], %%dx; inl (%%dx), %%eax"
102 : "=a" (out0), "=b" (rbx), "=c" (rcx),
103 "=d" (rdx), "=S" (rsi), "=D" (rdi)
104 : [port] "i" (VMWARE_HYPERVISOR_PORT),
105 "a" (VMWARE_HYPERVISOR_MAGIC),
106 "b" (in1),
107 "c" (cmd),
108 "d" (in3),
109 "S" (in4),
110 "D" (in5)
111 : "cc", "memory");
112 break;
113 }
114
115 if (out1)
116 *out1 = rbx;
117 if (out2)
118 *out2 = rcx;
119 if (out3)
120 *out3 = rdx;
121 if (out4)
122 *out4 = rsi;
123 if (out5)
124 *out5 = rdi;
125
126 return out0;
127 }
128
129 static inline int __vmware_platform(void)
130 {
131 u32 eax, ebx, ecx;
132
133 eax = vmware_hypercall3(VMWARE_CMD_GETVERSION, 0, &ebx, &ecx);
134 return eax != UINT_MAX && ebx == VMWARE_HYPERVISOR_MAGIC;
135 }
136
137 static unsigned long vmware_get_tsc_khz(void)
138 {
139 return vmware_tsc_khz;
140 }
141
142 #ifdef CONFIG_PARAVIRT
143 static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
144 static bool vmw_sched_clock __initdata = true;
145 static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
146 static bool has_steal_clock;
147 static bool steal_acc __initdata = true; /* steal time accounting */
148
149 static __init int setup_vmw_sched_clock(char *s)
150 {
151 vmw_sched_clock = false;
152 return 0;
153 }
154 early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
155
156 static __init int parse_no_stealacc(char *arg)
157 {
158 steal_acc = false;
159 return 0;
160 }
161 early_param("no-steal-acc", parse_no_stealacc);
162
163 static noinstr u64 vmware_sched_clock(void)
164 {
165 unsigned long long ns;
166
167 ns = mul_u64_u32_shr(rdtsc(), vmware_cyc2ns.cyc2ns_mul,
168 vmware_cyc2ns.cyc2ns_shift);
169 ns -= vmware_cyc2ns.cyc2ns_offset;
170 return ns;
171 }
172
173 static void __init vmware_cyc2ns_setup(void)
174 {
175 struct cyc2ns_data *d = &vmware_cyc2ns;
176 unsigned long long tsc_now = rdtsc();
177
178 clocks_calc_mult_shift(&d->cyc2ns_mul, &d->cyc2ns_shift,
179 vmware_tsc_khz, NSEC_PER_MSEC, 0);
180 d->cyc2ns_offset = mul_u64_u32_shr(tsc_now, d->cyc2ns_mul,
181 d->cyc2ns_shift);
182
183 pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset);
184 }
185
186 static int vmware_cmd_stealclock(u32 addr_hi, u32 addr_lo)
187 {
188 u32 info;
189
190 return vmware_hypercall5(VMWARE_CMD_STEALCLOCK, 0, 0, addr_hi, addr_lo,
191 &info);
192 }
193
194 static bool stealclock_enable(phys_addr_t pa)
195 {
196 return vmware_cmd_stealclock(upper_32_bits(pa),
197 lower_32_bits(pa)) == STEALCLOCK_ENABLED;
198 }
199
200 static int __stealclock_disable(void)
201 {
202 return vmware_cmd_stealclock(0, 1);
203 }
204
205 static void stealclock_disable(void)
206 {
207 __stealclock_disable();
208 }
209
210 static bool vmware_is_stealclock_available(void)
211 {
212 return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE;
213 }
214
215 /**
216 * vmware_steal_clock() - read the per-cpu steal clock
217 * @cpu: the cpu number whose steal clock we want to read
218 *
219 * The function reads the steal clock if we are on a 64-bit system, otherwise
220 * reads it in parts, checking that the high part didn't change in the
221 * meantime.
222 *
223 * Return:
224 * The steal clock reading in ns.
225 */
226 static u64 vmware_steal_clock(int cpu)
227 {
228 struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu);
229 u64 clock;
230
231 if (IS_ENABLED(CONFIG_64BIT))
232 clock = READ_ONCE(steal->clock);
233 else {
234 u32 initial_high, low, high;
235
236 do {
237 initial_high = READ_ONCE(steal->clock_high);
238 /* Do not reorder initial_high and high readings */
239 virt_rmb();
240 low = READ_ONCE(steal->clock_low);
241 /* Keep low reading in between */
242 virt_rmb();
243 high = READ_ONCE(steal->clock_high);
244 } while (initial_high != high);
245
246 clock = ((u64)high << 32) | low;
247 }
248
249 return mul_u64_u32_shr(clock, vmware_cyc2ns.cyc2ns_mul,
250 vmware_cyc2ns.cyc2ns_shift);
251 }
252
253 static void vmware_register_steal_time(void)
254 {
255 int cpu = smp_processor_id();
256 struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu);
257
258 if (!has_steal_clock)
259 return;
260
261 if (!stealclock_enable(slow_virt_to_phys(st))) {
262 has_steal_clock = false;
263 return;
264 }
265
266 pr_info("vmware-stealtime: cpu %d, pa %llx\n",
267 cpu, (unsigned long long) slow_virt_to_phys(st));
268 }
269
270 static void vmware_disable_steal_time(void)
271 {
272 if (!has_steal_clock)
273 return;
274
275 stealclock_disable();
276 }
277
278 static void vmware_guest_cpu_init(void)
279 {
280 if (has_steal_clock)
281 vmware_register_steal_time();
282 }
283
284 static void vmware_pv_guest_cpu_reboot(void *unused)
285 {
286 vmware_disable_steal_time();
287 }
288
289 static int vmware_pv_reboot_notify(struct notifier_block *nb,
290 unsigned long code, void *unused)
291 {
292 if (code == SYS_RESTART)
293 on_each_cpu(vmware_pv_guest_cpu_reboot, NULL, 1);
294 return NOTIFY_DONE;
295 }
296
297 static struct notifier_block vmware_pv_reboot_nb = {
298 .notifier_call = vmware_pv_reboot_notify,
299 };
300
301 #ifdef CONFIG_SMP
302 static void __init vmware_smp_prepare_boot_cpu(void)
303 {
304 vmware_guest_cpu_init();
305 native_smp_prepare_boot_cpu();
306 }
307
308 static int vmware_cpu_online(unsigned int cpu)
309 {
310 local_irq_disable();
311 vmware_guest_cpu_init();
312 local_irq_enable();
313 return 0;
314 }
315
316 static int vmware_cpu_down_prepare(unsigned int cpu)
317 {
318 local_irq_disable();
319 vmware_disable_steal_time();
320 local_irq_enable();
321 return 0;
322 }
323 #endif
324
325 static __init int activate_jump_labels(void)
326 {
327 if (has_steal_clock) {
328 static_key_slow_inc(¶virt_steal_enabled);
329 if (steal_acc)
330 static_key_slow_inc(¶virt_steal_rq_enabled);
331 }
332
333 return 0;
334 }
335 arch_initcall(activate_jump_labels);
336
337 static void __init vmware_paravirt_ops_setup(void)
338 {
339 pv_info.name = "VMware hypervisor";
340 pv_ops.cpu.io_delay = paravirt_nop;
341
342 if (vmware_tsc_khz == 0)
343 return;
344
345 vmware_cyc2ns_setup();
346
347 if (vmw_sched_clock)
348 paravirt_set_sched_clock(vmware_sched_clock);
349
350 if (vmware_is_stealclock_available()) {
351 has_steal_clock = true;
352 static_call_update(pv_steal_clock, vmware_steal_clock);
353
354 /* We use reboot notifier only to disable steal clock */
355 register_reboot_notifier(&vmware_pv_reboot_nb);
356
357 #ifdef CONFIG_SMP
358 smp_ops.smp_prepare_boot_cpu =
359 vmware_smp_prepare_boot_cpu;
360 if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
361 "x86/vmware:online",
362 vmware_cpu_online,
363 vmware_cpu_down_prepare) < 0)
364 pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n");
365 #else
366 vmware_guest_cpu_init();
367 #endif
368 }
369 }
370 #else
371 #define vmware_paravirt_ops_setup() do {} while (0)
372 #endif
373
374 /*
375 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
376 * Still, due to timing difference when running on virtual cpus, the TSC can
377 * be marked as unstable in some cases. For example, the TSC sync check at
378 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
379 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
380 * is not suitable as a watchdog when running on a hypervisor because the
381 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
382 * long time. To skip these checks at runtime we set these capability bits,
383 * so that the kernel could just trust the hypervisor with providing a
384 * reliable virtual TSC that is suitable for timekeeping.
385 */
386 static void __init vmware_set_capabilities(void)
387 {
388 setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
389 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
390 if (vmware_tsc_khz)
391 setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
392 if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)
393 setup_force_cpu_cap(X86_FEATURE_VMCALL);
394 else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)
395 setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL);
396 }
397
398 static void __init vmware_platform_setup(void)
399 {
400 u32 eax, ebx, ecx;
401 u64 lpj, tsc_khz;
402
403 eax = vmware_hypercall3(VMWARE_CMD_GETHZ, UINT_MAX, &ebx, &ecx);
404
405 if (ebx != UINT_MAX) {
406 lpj = tsc_khz = eax | (((u64)ebx) << 32);
407 do_div(tsc_khz, 1000);
408 WARN_ON(tsc_khz >> 32);
409 pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n",
410 (unsigned long) tsc_khz / 1000,
411 (unsigned long) tsc_khz % 1000);
412
413 if (!preset_lpj) {
414 do_div(lpj, HZ);
415 preset_lpj = lpj;
416 }
417
418 vmware_tsc_khz = tsc_khz;
419 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
420 x86_platform.calibrate_cpu = vmware_get_tsc_khz;
421
422 #ifdef CONFIG_X86_LOCAL_APIC
423 /* Skip lapic calibration since we know the bus frequency. */
424 lapic_timer_period = ecx / HZ;
425 pr_info("Host bus clock speed read from hypervisor : %u Hz\n",
426 ecx);
427 #endif
428 } else {
429 pr_warn("Failed to get TSC freq from the hypervisor\n");
430 }
431
432 vmware_paravirt_ops_setup();
433
434 #ifdef CONFIG_X86_IO_APIC
435 no_timer_check = 1;
436 #endif
437
438 vmware_set_capabilities();
439 }
440
441 static u8 __init vmware_select_hypercall(void)
442 {
443 int eax, ebx, ecx, edx;
444
445 cpuid(CPUID_VMWARE_FEATURES_LEAF, &eax, &ebx, &ecx, &edx);
446 return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL |
447 CPUID_VMWARE_FEATURES_ECX_VMCALL));
448 }
449
450 /*
451 * While checking the dmi string information, just checking the product
452 * serial key should be enough, as this will always have a VMware
453 * specific string when running under VMware hypervisor.
454 * If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode
455 * intentionally defaults to 0.
456 */
457 static u32 __init vmware_platform(void)
458 {
459 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
460 unsigned int eax;
461 unsigned int hyper_vendor_id[3];
462
463 cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
464 &hyper_vendor_id[1], &hyper_vendor_id[2]);
465 if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) {
466 if (eax >= CPUID_VMWARE_FEATURES_LEAF)
467 vmware_hypercall_mode =
468 vmware_select_hypercall();
469
470 pr_info("hypercall mode: 0x%02x\n",
471 (unsigned int) vmware_hypercall_mode);
472
473 return CPUID_VMWARE_INFO_LEAF;
474 }
475 } else if (dmi_available && dmi_name_in_serial("VMware") &&
476 __vmware_platform())
477 return 1;
478
479 return 0;
480 }
481
482 /* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
483 static bool __init vmware_legacy_x2apic_available(void)
484 {
485 u32 eax;
486
487 eax = vmware_hypercall1(VMWARE_CMD_GETVCPU_INFO, 0);
488 return !(eax & GETVCPU_INFO_VCPU_RESERVED) &&
489 (eax & GETVCPU_INFO_LEGACY_X2APIC);
490 }
491
492 #ifdef CONFIG_INTEL_TDX_GUEST
493 /*
494 * TDCALL[TDG.VP.VMCALL] uses %rax (arg0) and %rcx (arg2). Therefore,
495 * we remap those registers to %r12 and %r13, respectively.
496 */
497 unsigned long vmware_tdx_hypercall(unsigned long cmd,
498 unsigned long in1, unsigned long in3,
499 unsigned long in4, unsigned long in5,
500 u32 *out1, u32 *out2, u32 *out3,
501 u32 *out4, u32 *out5)
502 {
503 struct tdx_module_args args = {};
504
505 if (!hypervisor_is_type(X86_HYPER_VMWARE)) {
506 pr_warn_once("Incorrect usage\n");
507 return ULONG_MAX;
508 }
509
510 if (cmd & ~VMWARE_CMD_MASK) {
511 pr_warn_once("Out of range command %lx\n", cmd);
512 return ULONG_MAX;
513 }
514
515 args.rbx = in1;
516 args.rdx = in3;
517 args.rsi = in4;
518 args.rdi = in5;
519 args.r10 = VMWARE_TDX_VENDOR_LEAF;
520 args.r11 = VMWARE_TDX_HCALL_FUNC;
521 args.r12 = VMWARE_HYPERVISOR_MAGIC;
522 args.r13 = cmd;
523 /* CPL */
524 args.r15 = 0;
525
526 __tdx_hypercall(&args);
527
528 if (out1)
529 *out1 = args.rbx;
530 if (out2)
531 *out2 = args.r13;
532 if (out3)
533 *out3 = args.rdx;
534 if (out4)
535 *out4 = args.rsi;
536 if (out5)
537 *out5 = args.rdi;
538
539 return args.r12;
540 }
541 EXPORT_SYMBOL_GPL(vmware_tdx_hypercall);
542 #endif
543
544 #ifdef CONFIG_AMD_MEM_ENCRYPT
545 static void vmware_sev_es_hcall_prepare(struct ghcb *ghcb,
546 struct pt_regs *regs)
547 {
548 /* Copy VMWARE specific Hypercall parameters to the GHCB */
549 ghcb_set_rip(ghcb, regs->ip);
550 ghcb_set_rbx(ghcb, regs->bx);
551 ghcb_set_rcx(ghcb, regs->cx);
552 ghcb_set_rdx(ghcb, regs->dx);
553 ghcb_set_rsi(ghcb, regs->si);
554 ghcb_set_rdi(ghcb, regs->di);
555 ghcb_set_rbp(ghcb, regs->bp);
556 }
557
558 static bool vmware_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
559 {
560 if (!(ghcb_rbx_is_valid(ghcb) &&
561 ghcb_rcx_is_valid(ghcb) &&
562 ghcb_rdx_is_valid(ghcb) &&
563 ghcb_rsi_is_valid(ghcb) &&
564 ghcb_rdi_is_valid(ghcb) &&
565 ghcb_rbp_is_valid(ghcb)))
566 return false;
567
568 regs->bx = ghcb_get_rbx(ghcb);
569 regs->cx = ghcb_get_rcx(ghcb);
570 regs->dx = ghcb_get_rdx(ghcb);
571 regs->si = ghcb_get_rsi(ghcb);
572 regs->di = ghcb_get_rdi(ghcb);
573 regs->bp = ghcb_get_rbp(ghcb);
574
575 return true;
576 }
577 #endif
578
579 const __initconst struct hypervisor_x86 x86_hyper_vmware = {
580 .name = "VMware",
581 .detect = vmware_platform,
582 .type = X86_HYPER_VMWARE,
583 .init.init_platform = vmware_platform_setup,
584 .init.x2apic_available = vmware_legacy_x2apic_available,
585 #ifdef CONFIG_AMD_MEM_ENCRYPT
586 .runtime.sev_es_hcall_prepare = vmware_sev_es_hcall_prepare,
587 .runtime.sev_es_hcall_finish = vmware_sev_es_hcall_finish,
588 #endif
589 };
590
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