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/efi.h>
30#include <linux/reboot.h>
31#include <linux/static_call.h>
32#include <asm/div64.h>
33#include <asm/x86_init.h>
34#include <asm/hypervisor.h>
35#include <asm/timer.h>
36#include <asm/apic.h>
37#include <asm/vmware.h>
38#include <asm/svm.h>
39
40#undef pr_fmt
41#define pr_fmt(fmt) "vmware: " fmt
42
43#define CPUID_VMWARE_INFO_LEAF 0x40000000
44#define CPUID_VMWARE_FEATURES_LEAF 0x40000010
45
46#define GETVCPU_INFO_LEGACY_X2APIC BIT(3)
47#define GETVCPU_INFO_VCPU_RESERVED BIT(31)
48
49#define STEALCLOCK_NOT_AVAILABLE (-1)
50#define STEALCLOCK_DISABLED 0
51#define STEALCLOCK_ENABLED 1
52
53struct vmware_steal_time {
54 union {
55 u64 clock; /* stolen time counter in units of vtsc */
56 struct {
57 /* only for little-endian */
58 u32 clock_low;
59 u32 clock_high;
60 };
61 };
62 u64 reserved[7];
63};
64
65static unsigned long vmware_tsc_khz __ro_after_init;
66static u8 vmware_hypercall_mode __ro_after_init;
67
68unsigned long vmware_hypercall_slow(unsigned long cmd,
69 unsigned long in1, unsigned long in3,
70 unsigned long in4, unsigned long in5,
71 u32 *out1, u32 *out2, u32 *out3,
72 u32 *out4, u32 *out5)
73{
74 unsigned long out0, rbx, rcx, rdx, rsi, rdi;
75
76 switch (vmware_hypercall_mode) {
77 case CPUID_VMWARE_FEATURES_ECX_VMCALL:
78 asm_inline volatile ("vmcall"
79 : "=a" (out0), "=b" (rbx), "=c" (rcx),
80 "=d" (rdx), "=S" (rsi), "=D" (rdi)
81 : "a" (VMWARE_HYPERVISOR_MAGIC),
82 "b" (in1),
83 "c" (cmd),
84 "d" (in3),
85 "S" (in4),
86 "D" (in5)
87 : "cc", "memory");
88 break;
89 case CPUID_VMWARE_FEATURES_ECX_VMMCALL:
90 asm_inline volatile ("vmmcall"
91 : "=a" (out0), "=b" (rbx), "=c" (rcx),
92 "=d" (rdx), "=S" (rsi), "=D" (rdi)
93 : "a" (VMWARE_HYPERVISOR_MAGIC),
94 "b" (in1),
95 "c" (cmd),
96 "d" (in3),
97 "S" (in4),
98 "D" (in5)
99 : "cc", "memory");
100 break;
101 default:
102 asm_inline volatile ("movw %[port], %%dx; inl (%%dx), %%eax"
103 : "=a" (out0), "=b" (rbx), "=c" (rcx),
104 "=d" (rdx), "=S" (rsi), "=D" (rdi)
105 : [port] "i" (VMWARE_HYPERVISOR_PORT),
106 "a" (VMWARE_HYPERVISOR_MAGIC),
107 "b" (in1),
108 "c" (cmd),
109 "d" (in3),
110 "S" (in4),
111 "D" (in5)
112 : "cc", "memory");
113 break;
114 }
115
116 if (out1)
117 *out1 = rbx;
118 if (out2)
119 *out2 = rcx;
120 if (out3)
121 *out3 = rdx;
122 if (out4)
123 *out4 = rsi;
124 if (out5)
125 *out5 = rdi;
126
127 return out0;
128}
129
130static inline int __vmware_platform(void)
131{
132 u32 eax, ebx, ecx;
133
134 eax = vmware_hypercall3(VMWARE_CMD_GETVERSION, in1: 0, out1: &ebx, out2: &ecx);
135 return eax != UINT_MAX && ebx == VMWARE_HYPERVISOR_MAGIC;
136}
137
138static unsigned long vmware_get_tsc_khz(void)
139{
140 return vmware_tsc_khz;
141}
142
143#ifdef CONFIG_PARAVIRT
144static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
145static bool vmw_sched_clock __initdata = true;
146static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
147static bool has_steal_clock;
148static bool steal_acc __initdata = true; /* steal time accounting */
149
150static __init int setup_vmw_sched_clock(char *s)
151{
152 vmw_sched_clock = false;
153 return 0;
154}
155early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
156
157static __init int parse_no_stealacc(char *arg)
158{
159 steal_acc = false;
160 return 0;
161}
162early_param("no-steal-acc", parse_no_stealacc);
163
164static noinstr u64 vmware_sched_clock(void)
165{
166 unsigned long long ns;
167
168 ns = mul_u64_u32_shr(a: rdtsc(), mul: vmware_cyc2ns.cyc2ns_mul,
169 shift: vmware_cyc2ns.cyc2ns_shift);
170 ns -= vmware_cyc2ns.cyc2ns_offset;
171 return ns;
172}
173
174static void __init vmware_cyc2ns_setup(void)
175{
176 struct cyc2ns_data *d = &vmware_cyc2ns;
177 unsigned long long tsc_now = rdtsc();
178
179 clocks_calc_mult_shift(mult: &d->cyc2ns_mul, shift: &d->cyc2ns_shift,
180 from: vmware_tsc_khz, NSEC_PER_MSEC, minsec: 0);
181 d->cyc2ns_offset = mul_u64_u32_shr(a: tsc_now, mul: d->cyc2ns_mul,
182 shift: d->cyc2ns_shift);
183
184 pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset);
185}
186
187static int vmware_cmd_stealclock(u32 addr_hi, u32 addr_lo)
188{
189 u32 info;
190
191 return vmware_hypercall5(VMWARE_CMD_STEALCLOCK, in1: 0, in3: 0, in4: addr_hi, in5: addr_lo,
192 out2: &info);
193}
194
195static bool stealclock_enable(phys_addr_t pa)
196{
197 return vmware_cmd_stealclock(upper_32_bits(pa),
198 lower_32_bits(pa)) == STEALCLOCK_ENABLED;
199}
200
201static int __stealclock_disable(void)
202{
203 return vmware_cmd_stealclock(addr_hi: 0, addr_lo: 1);
204}
205
206static void stealclock_disable(void)
207{
208 __stealclock_disable();
209}
210
211static bool vmware_is_stealclock_available(void)
212{
213 return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE;
214}
215
216/**
217 * vmware_steal_clock() - read the per-cpu steal clock
218 * @cpu: the cpu number whose steal clock we want to read
219 *
220 * The function reads the steal clock if we are on a 64-bit system, otherwise
221 * reads it in parts, checking that the high part didn't change in the
222 * meantime.
223 *
224 * Return:
225 * The steal clock reading in ns.
226 */
227static u64 vmware_steal_clock(int cpu)
228{
229 struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu);
230 u64 clock;
231
232 if (IS_ENABLED(CONFIG_64BIT))
233 clock = READ_ONCE(steal->clock);
234 else {
235 u32 initial_high, low, high;
236
237 do {
238 initial_high = READ_ONCE(steal->clock_high);
239 /* Do not reorder initial_high and high readings */
240 virt_rmb();
241 low = READ_ONCE(steal->clock_low);
242 /* Keep low reading in between */
243 virt_rmb();
244 high = READ_ONCE(steal->clock_high);
245 } while (initial_high != high);
246
247 clock = ((u64)high << 32) | low;
248 }
249
250 return mul_u64_u32_shr(a: clock, mul: vmware_cyc2ns.cyc2ns_mul,
251 shift: vmware_cyc2ns.cyc2ns_shift);
252}
253
254static void vmware_register_steal_time(void)
255{
256 int cpu = smp_processor_id();
257 struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu);
258
259 if (!has_steal_clock)
260 return;
261
262 if (!stealclock_enable(pa: slow_virt_to_phys(address: st))) {
263 has_steal_clock = false;
264 return;
265 }
266
267 pr_info("vmware-stealtime: cpu %d, pa %llx\n",
268 cpu, (unsigned long long) slow_virt_to_phys(st));
269}
270
271static void vmware_disable_steal_time(void)
272{
273 if (!has_steal_clock)
274 return;
275
276 stealclock_disable();
277}
278
279static void vmware_guest_cpu_init(void)
280{
281 if (has_steal_clock)
282 vmware_register_steal_time();
283}
284
285static void vmware_pv_guest_cpu_reboot(void *unused)
286{
287 vmware_disable_steal_time();
288}
289
290static int vmware_pv_reboot_notify(struct notifier_block *nb,
291 unsigned long code, void *unused)
292{
293 if (code == SYS_RESTART)
294 on_each_cpu(func: vmware_pv_guest_cpu_reboot, NULL, wait: 1);
295 return NOTIFY_DONE;
296}
297
298static struct notifier_block vmware_pv_reboot_nb = {
299 .notifier_call = vmware_pv_reboot_notify,
300};
301
302#ifdef CONFIG_SMP
303static void __init vmware_smp_prepare_boot_cpu(void)
304{
305 vmware_guest_cpu_init();
306 native_smp_prepare_boot_cpu();
307}
308
309static int vmware_cpu_online(unsigned int cpu)
310{
311 local_irq_disable();
312 vmware_guest_cpu_init();
313 local_irq_enable();
314 return 0;
315}
316
317static int vmware_cpu_down_prepare(unsigned int cpu)
318{
319 local_irq_disable();
320 vmware_disable_steal_time();
321 local_irq_enable();
322 return 0;
323}
324#endif
325
326static __init int activate_jump_labels(void)
327{
328 if (has_steal_clock) {
329 static_key_slow_inc(key: &paravirt_steal_enabled);
330 if (steal_acc)
331 static_key_slow_inc(key: &paravirt_steal_rq_enabled);
332 }
333
334 return 0;
335}
336arch_initcall(activate_jump_labels);
337
338static void __init vmware_paravirt_ops_setup(void)
339{
340 pv_info.name = "VMware hypervisor";
341 pv_ops.cpu.io_delay = paravirt_nop;
342
343 if (vmware_tsc_khz == 0)
344 return;
345
346 vmware_cyc2ns_setup();
347
348 if (vmw_sched_clock)
349 paravirt_set_sched_clock(func: vmware_sched_clock);
350
351 if (vmware_is_stealclock_available()) {
352 has_steal_clock = true;
353 static_call_update(pv_steal_clock, vmware_steal_clock);
354
355 /* We use reboot notifier only to disable steal clock */
356 register_reboot_notifier(&vmware_pv_reboot_nb);
357
358#ifdef CONFIG_SMP
359 smp_ops.smp_prepare_boot_cpu =
360 vmware_smp_prepare_boot_cpu;
361 if (cpuhp_setup_state_nocalls(state: CPUHP_AP_ONLINE_DYN,
362 name: "x86/vmware:online",
363 startup: vmware_cpu_online,
364 teardown: vmware_cpu_down_prepare) < 0)
365 pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n");
366#else
367 vmware_guest_cpu_init();
368#endif
369 }
370}
371#else
372#define vmware_paravirt_ops_setup() do {} while (0)
373#endif
374
375/*
376 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
377 * Still, due to timing difference when running on virtual cpus, the TSC can
378 * be marked as unstable in some cases. For example, the TSC sync check at
379 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
380 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
381 * is not suitable as a watchdog when running on a hypervisor because the
382 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
383 * long time. To skip these checks at runtime we set these capability bits,
384 * so that the kernel could just trust the hypervisor with providing a
385 * reliable virtual TSC that is suitable for timekeeping.
386 */
387static void __init vmware_set_capabilities(void)
388{
389 setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
390 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
391 if (vmware_tsc_khz)
392 setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
393 if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)
394 setup_force_cpu_cap(X86_FEATURE_VMCALL);
395 else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)
396 setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL);
397}
398
399static void __init vmware_platform_setup(void)
400{
401 u32 eax, ebx, ecx;
402 u64 lpj, tsc_khz;
403
404 eax = vmware_hypercall3(VMWARE_CMD_GETHZ, UINT_MAX, out1: &ebx, out2: &ecx);
405
406 if (ebx != UINT_MAX) {
407 lpj = tsc_khz = eax | (((u64)ebx) << 32);
408 do_div(tsc_khz, 1000);
409 WARN_ON(tsc_khz >> 32);
410 pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n",
411 (unsigned long) tsc_khz / 1000,
412 (unsigned long) tsc_khz % 1000);
413
414 if (!preset_lpj) {
415 do_div(lpj, HZ);
416 preset_lpj = lpj;
417 }
418
419 vmware_tsc_khz = tsc_khz;
420 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
421 x86_platform.calibrate_cpu = vmware_get_tsc_khz;
422
423#ifdef CONFIG_X86_LOCAL_APIC
424 /* Skip lapic calibration since we know the bus frequency. */
425 lapic_timer_period = ecx / HZ;
426 pr_info("Host bus clock speed read from hypervisor : %u Hz\n",
427 ecx);
428#endif
429 } else {
430 pr_warn("Failed to get TSC freq from the hypervisor\n");
431 }
432
433 if (cc_platform_has(attr: CC_ATTR_GUEST_SEV_SNP) && !efi_enabled(EFI_BOOT))
434 x86_init.mpparse.find_mptable = mpparse_find_mptable;
435
436 vmware_paravirt_ops_setup();
437
438#ifdef CONFIG_X86_IO_APIC
439 no_timer_check = 1;
440#endif
441
442 vmware_set_capabilities();
443}
444
445static u8 __init vmware_select_hypercall(void)
446{
447 int eax, ebx, ecx, edx;
448
449 cpuid(CPUID_VMWARE_FEATURES_LEAF, eax: &eax, ebx: &ebx, ecx: &ecx, edx: &edx);
450 return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL |
451 CPUID_VMWARE_FEATURES_ECX_VMCALL));
452}
453
454/*
455 * While checking the dmi string information, just checking the product
456 * serial key should be enough, as this will always have a VMware
457 * specific string when running under VMware hypervisor.
458 * If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode
459 * intentionally defaults to 0.
460 */
461static u32 __init vmware_platform(void)
462{
463 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
464 unsigned int eax;
465 unsigned int hyper_vendor_id[3];
466
467 cpuid(CPUID_VMWARE_INFO_LEAF, eax: &eax, ebx: &hyper_vendor_id[0],
468 ecx: &hyper_vendor_id[1], edx: &hyper_vendor_id[2]);
469 if (!memcmp(p: hyper_vendor_id, q: "VMwareVMware", size: 12)) {
470 if (eax >= CPUID_VMWARE_FEATURES_LEAF)
471 vmware_hypercall_mode =
472 vmware_select_hypercall();
473
474 pr_info("hypercall mode: 0x%02x\n",
475 (unsigned int) vmware_hypercall_mode);
476
477 return CPUID_VMWARE_INFO_LEAF;
478 }
479 } else if (dmi_available && dmi_name_in_serial(str: "VMware") &&
480 __vmware_platform())
481 return 1;
482
483 return 0;
484}
485
486/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
487static bool __init vmware_legacy_x2apic_available(void)
488{
489 u32 eax;
490
491 eax = vmware_hypercall1(VMWARE_CMD_GETVCPU_INFO, in1: 0);
492 return !(eax & GETVCPU_INFO_VCPU_RESERVED) &&
493 (eax & GETVCPU_INFO_LEGACY_X2APIC);
494}
495
496#ifdef CONFIG_INTEL_TDX_GUEST
497/*
498 * TDCALL[TDG.VP.VMCALL] uses %rax (arg0) and %rcx (arg2). Therefore,
499 * we remap those registers to %r12 and %r13, respectively.
500 */
501unsigned long vmware_tdx_hypercall(unsigned long cmd,
502 unsigned long in1, unsigned long in3,
503 unsigned long in4, unsigned long in5,
504 u32 *out1, u32 *out2, u32 *out3,
505 u32 *out4, u32 *out5)
506{
507 struct tdx_module_args args = {};
508
509 if (!hypervisor_is_type(type: X86_HYPER_VMWARE)) {
510 pr_warn_once("Incorrect usage\n");
511 return ULONG_MAX;
512 }
513
514 if (cmd & ~VMWARE_CMD_MASK) {
515 pr_warn_once("Out of range command %lx\n", cmd);
516 return ULONG_MAX;
517 }
518
519 args.rbx = in1;
520 args.rdx = in3;
521 args.rsi = in4;
522 args.rdi = in5;
523 args.r10 = VMWARE_TDX_VENDOR_LEAF;
524 args.r11 = VMWARE_TDX_HCALL_FUNC;
525 args.r12 = VMWARE_HYPERVISOR_MAGIC;
526 args.r13 = cmd;
527 /* CPL */
528 args.r15 = 0;
529
530 __tdx_hypercall(args: &args);
531
532 if (out1)
533 *out1 = args.rbx;
534 if (out2)
535 *out2 = args.r13;
536 if (out3)
537 *out3 = args.rdx;
538 if (out4)
539 *out4 = args.rsi;
540 if (out5)
541 *out5 = args.rdi;
542
543 return args.r12;
544}
545EXPORT_SYMBOL_GPL(vmware_tdx_hypercall);
546#endif
547
548#ifdef CONFIG_AMD_MEM_ENCRYPT
549static void vmware_sev_es_hcall_prepare(struct ghcb *ghcb,
550 struct pt_regs *regs)
551{
552 /* Copy VMWARE specific Hypercall parameters to the GHCB */
553 ghcb_set_rip(ghcb, value: regs->ip);
554 ghcb_set_rbx(ghcb, value: regs->bx);
555 ghcb_set_rcx(ghcb, value: regs->cx);
556 ghcb_set_rdx(ghcb, value: regs->dx);
557 ghcb_set_rsi(ghcb, value: regs->si);
558 ghcb_set_rdi(ghcb, value: regs->di);
559 ghcb_set_rbp(ghcb, value: regs->bp);
560}
561
562static bool vmware_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
563{
564 if (!(ghcb_rbx_is_valid(ghcb) &&
565 ghcb_rcx_is_valid(ghcb) &&
566 ghcb_rdx_is_valid(ghcb) &&
567 ghcb_rsi_is_valid(ghcb) &&
568 ghcb_rdi_is_valid(ghcb) &&
569 ghcb_rbp_is_valid(ghcb)))
570 return false;
571
572 regs->bx = ghcb_get_rbx(ghcb);
573 regs->cx = ghcb_get_rcx(ghcb);
574 regs->dx = ghcb_get_rdx(ghcb);
575 regs->si = ghcb_get_rsi(ghcb);
576 regs->di = ghcb_get_rdi(ghcb);
577 regs->bp = ghcb_get_rbp(ghcb);
578
579 return true;
580}
581#endif
582
583const __initconst struct hypervisor_x86 x86_hyper_vmware = {
584 .name = "VMware",
585 .detect = vmware_platform,
586 .type = X86_HYPER_VMWARE,
587 .init.init_platform = vmware_platform_setup,
588 .init.x2apic_available = vmware_legacy_x2apic_available,
589#ifdef CONFIG_AMD_MEM_ENCRYPT
590 .runtime.sev_es_hcall_prepare = vmware_sev_es_hcall_prepare,
591 .runtime.sev_es_hcall_finish = vmware_sev_es_hcall_finish,
592#endif
593};
594

source code of linux/arch/x86/kernel/cpu/vmware.c