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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/module.h>
26#include <asm/div64.h>
27#include <asm/x86_init.h>
28#include <asm/hypervisor.h>
29
30#define CPUID_VMWARE_INFO_LEAF 0x40000000
31#define VMWARE_HYPERVISOR_MAGIC 0x564D5868
32#define VMWARE_HYPERVISOR_PORT 0x5658
33
34#define VMWARE_PORT_CMD_GETVERSION 10
35#define VMWARE_PORT_CMD_GETHZ 45
36
37#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
38 __asm__("inl (%%dx)" : \
39 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
40 "0"(VMWARE_HYPERVISOR_MAGIC), \
41 "1"(VMWARE_PORT_CMD_##cmd), \
42 "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \
43 "memory");
44
45static inline int __vmware_platform(void)
46{
47 uint32_t eax, ebx, ecx, edx;
48 VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
49 return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
50}
51
52static unsigned long vmware_get_tsc_khz(void)
53{
54 uint64_t tsc_hz, lpj;
55 uint32_t eax, ebx, ecx, edx;
56
57 VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
58
59 tsc_hz = eax | (((uint64_t)ebx) << 32);
60 do_div(tsc_hz, 1000);
61 BUG_ON(tsc_hz >> 32);
62 printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n",
63 (unsigned long) tsc_hz / 1000,
64 (unsigned long) tsc_hz % 1000);
65
66 if (!preset_lpj) {
67 lpj = ((u64)tsc_hz * 1000);
68 do_div(lpj, HZ);
69 preset_lpj = lpj;
70 }
71
72 return tsc_hz;
73}
74
75static void __init vmware_platform_setup(void)
76{
77 uint32_t eax, ebx, ecx, edx;
78
79 VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
80
81 if (ebx != UINT_MAX)
82 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
83 else
84 printk(KERN_WARNING
85 "Failed to get TSC freq from the hypervisor\n");
86}
87
88/*
89 * While checking the dmi string information, just checking the product
90 * serial key should be enough, as this will always have a VMware
91 * specific string when running under VMware hypervisor.
92 */
93static bool __init vmware_platform(void)
94{
95 if (cpu_has_hypervisor) {
96 unsigned int eax;
97 unsigned int hyper_vendor_id[3];
98
99 cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
100 &hyper_vendor_id[1], &hyper_vendor_id[2]);
101 if (!memcmp(hyper_vendor_id, "VMwareVMware", 12))
102 return true;
103 } else if (dmi_available && dmi_name_in_serial("VMware") &&
104 __vmware_platform())
105 return true;
106
107 return false;
108}
109
110/*
111 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
112 * Still, due to timing difference when running on virtual cpus, the TSC can
113 * be marked as unstable in some cases. For example, the TSC sync check at
114 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
115 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
116 * is not suitable as a watchdog when running on a hypervisor because the
117 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
118 * long time. To skip these checks at runtime we set these capability bits,
119 * so that the kernel could just trust the hypervisor with providing a
120 * reliable virtual TSC that is suitable for timekeeping.
121 */
122static void __cpuinit vmware_set_cpu_features(struct cpuinfo_x86 *c)
123{
124 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
125 set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
126}
127
128const __refconst struct hypervisor_x86 x86_hyper_vmware = {
129 .name = "VMware",
130 .detect = vmware_platform,
131 .set_cpu_features = vmware_set_cpu_features,
132 .init_platform = vmware_platform_setup,
133};
134EXPORT_SYMBOL(x86_hyper_vmware);
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 <asm/div64.h>
31#include <asm/x86_init.h>
32#include <asm/hypervisor.h>
33#include <asm/timer.h>
34#include <asm/apic.h>
35#include <asm/vmware.h>
36
37#undef pr_fmt
38#define pr_fmt(fmt) "vmware: " fmt
39
40#define CPUID_VMWARE_INFO_LEAF 0x40000000
41#define CPUID_VMWARE_FEATURES_LEAF 0x40000010
42#define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0)
43#define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1)
44
45#define VMWARE_HYPERVISOR_MAGIC 0x564D5868
46
47#define VMWARE_CMD_GETVERSION 10
48#define VMWARE_CMD_GETHZ 45
49#define VMWARE_CMD_GETVCPU_INFO 68
50#define VMWARE_CMD_LEGACY_X2APIC 3
51#define VMWARE_CMD_VCPU_RESERVED 31
52#define VMWARE_CMD_STEALCLOCK 91
53
54#define STEALCLOCK_NOT_AVAILABLE (-1)
55#define STEALCLOCK_DISABLED 0
56#define STEALCLOCK_ENABLED 1
57
58#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
59 __asm__("inl (%%dx), %%eax" : \
60 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
61 "a"(VMWARE_HYPERVISOR_MAGIC), \
62 "c"(VMWARE_CMD_##cmd), \
63 "d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \
64 "memory")
65
66#define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \
67 __asm__("vmcall" : \
68 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
69 "a"(VMWARE_HYPERVISOR_MAGIC), \
70 "c"(VMWARE_CMD_##cmd), \
71 "d"(0), "b"(UINT_MAX) : \
72 "memory")
73
74#define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \
75 __asm__("vmmcall" : \
76 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
77 "a"(VMWARE_HYPERVISOR_MAGIC), \
78 "c"(VMWARE_CMD_##cmd), \
79 "d"(0), "b"(UINT_MAX) : \
80 "memory")
81
82#define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \
83 switch (vmware_hypercall_mode) { \
84 case CPUID_VMWARE_FEATURES_ECX_VMCALL: \
85 VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \
86 break; \
87 case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \
88 VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \
89 break; \
90 default: \
91 VMWARE_PORT(cmd, eax, ebx, ecx, edx); \
92 break; \
93 } \
94 } while (0)
95
96struct vmware_steal_time {
97 union {
98 uint64_t clock; /* stolen time counter in units of vtsc */
99 struct {
100 /* only for little-endian */
101 uint32_t clock_low;
102 uint32_t clock_high;
103 };
104 };
105 uint64_t reserved[7];
106};
107
108static unsigned long vmware_tsc_khz __ro_after_init;
109static u8 vmware_hypercall_mode __ro_after_init;
110
111static inline int __vmware_platform(void)
112{
113 uint32_t eax, ebx, ecx, edx;
114 VMWARE_CMD(GETVERSION, eax, ebx, ecx, edx);
115 return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
116}
117
118static unsigned long vmware_get_tsc_khz(void)
119{
120 return vmware_tsc_khz;
121}
122
123#ifdef CONFIG_PARAVIRT
124static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
125static bool vmw_sched_clock __initdata = true;
126static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
127static bool has_steal_clock;
128static bool steal_acc __initdata = true; /* steal time accounting */
129
130static __init int setup_vmw_sched_clock(char *s)
131{
132 vmw_sched_clock = false;
133 return 0;
134}
135early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
136
137static __init int parse_no_stealacc(char *arg)
138{
139 steal_acc = false;
140 return 0;
141}
142early_param("no-steal-acc", parse_no_stealacc);
143
144static unsigned long long notrace vmware_sched_clock(void)
145{
146 unsigned long long ns;
147
148 ns = mul_u64_u32_shr(rdtsc(), vmware_cyc2ns.cyc2ns_mul,
149 vmware_cyc2ns.cyc2ns_shift);
150 ns -= vmware_cyc2ns.cyc2ns_offset;
151 return ns;
152}
153
154static void __init vmware_cyc2ns_setup(void)
155{
156 struct cyc2ns_data *d = &vmware_cyc2ns;
157 unsigned long long tsc_now = rdtsc();
158
159 clocks_calc_mult_shift(&d->cyc2ns_mul, &d->cyc2ns_shift,
160 vmware_tsc_khz, NSEC_PER_MSEC, 0);
161 d->cyc2ns_offset = mul_u64_u32_shr(tsc_now, d->cyc2ns_mul,
162 d->cyc2ns_shift);
163
164 pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset);
165}
166
167static int vmware_cmd_stealclock(uint32_t arg1, uint32_t arg2)
168{
169 uint32_t result, info;
170
171 asm volatile (VMWARE_HYPERCALL :
172 "=a"(result),
173 "=c"(info) :
174 "a"(VMWARE_HYPERVISOR_MAGIC),
175 "b"(0),
176 "c"(VMWARE_CMD_STEALCLOCK),
177 "d"(0),
178 "S"(arg1),
179 "D"(arg2) :
180 "memory");
181 return result;
182}
183
184static bool stealclock_enable(phys_addr_t pa)
185{
186 return vmware_cmd_stealclock(upper_32_bits(pa),
187 lower_32_bits(pa)) == STEALCLOCK_ENABLED;
188}
189
190static int __stealclock_disable(void)
191{
192 return vmware_cmd_stealclock(0, 1);
193}
194
195static void stealclock_disable(void)
196{
197 __stealclock_disable();
198}
199
200static bool vmware_is_stealclock_available(void)
201{
202 return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE;
203}
204
205/**
206 * vmware_steal_clock() - read the per-cpu steal clock
207 * @cpu: the cpu number whose steal clock we want to read
208 *
209 * The function reads the steal clock if we are on a 64-bit system, otherwise
210 * reads it in parts, checking that the high part didn't change in the
211 * meantime.
212 *
213 * Return:
214 * The steal clock reading in ns.
215 */
216static uint64_t vmware_steal_clock(int cpu)
217{
218 struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu);
219 uint64_t clock;
220
221 if (IS_ENABLED(CONFIG_64BIT))
222 clock = READ_ONCE(steal->clock);
223 else {
224 uint32_t initial_high, low, high;
225
226 do {
227 initial_high = READ_ONCE(steal->clock_high);
228 /* Do not reorder initial_high and high readings */
229 virt_rmb();
230 low = READ_ONCE(steal->clock_low);
231 /* Keep low reading in between */
232 virt_rmb();
233 high = READ_ONCE(steal->clock_high);
234 } while (initial_high != high);
235
236 clock = ((uint64_t)high << 32) | low;
237 }
238
239 return mul_u64_u32_shr(clock, vmware_cyc2ns.cyc2ns_mul,
240 vmware_cyc2ns.cyc2ns_shift);
241}
242
243static void vmware_register_steal_time(void)
244{
245 int cpu = smp_processor_id();
246 struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu);
247
248 if (!has_steal_clock)
249 return;
250
251 if (!stealclock_enable(slow_virt_to_phys(st))) {
252 has_steal_clock = false;
253 return;
254 }
255
256 pr_info("vmware-stealtime: cpu %d, pa %llx\n",
257 cpu, (unsigned long long) slow_virt_to_phys(st));
258}
259
260static void vmware_disable_steal_time(void)
261{
262 if (!has_steal_clock)
263 return;
264
265 stealclock_disable();
266}
267
268static void vmware_guest_cpu_init(void)
269{
270 if (has_steal_clock)
271 vmware_register_steal_time();
272}
273
274static void vmware_pv_guest_cpu_reboot(void *unused)
275{
276 vmware_disable_steal_time();
277}
278
279static int vmware_pv_reboot_notify(struct notifier_block *nb,
280 unsigned long code, void *unused)
281{
282 if (code == SYS_RESTART)
283 on_each_cpu(vmware_pv_guest_cpu_reboot, NULL, 1);
284 return NOTIFY_DONE;
285}
286
287static struct notifier_block vmware_pv_reboot_nb = {
288 .notifier_call = vmware_pv_reboot_notify,
289};
290
291#ifdef CONFIG_SMP
292static void __init vmware_smp_prepare_boot_cpu(void)
293{
294 vmware_guest_cpu_init();
295 native_smp_prepare_boot_cpu();
296}
297
298static int vmware_cpu_online(unsigned int cpu)
299{
300 local_irq_disable();
301 vmware_guest_cpu_init();
302 local_irq_enable();
303 return 0;
304}
305
306static int vmware_cpu_down_prepare(unsigned int cpu)
307{
308 local_irq_disable();
309 vmware_disable_steal_time();
310 local_irq_enable();
311 return 0;
312}
313#endif
314
315static __init int activate_jump_labels(void)
316{
317 if (has_steal_clock) {
318 static_key_slow_inc(¶virt_steal_enabled);
319 if (steal_acc)
320 static_key_slow_inc(¶virt_steal_rq_enabled);
321 }
322
323 return 0;
324}
325arch_initcall(activate_jump_labels);
326
327static void __init vmware_paravirt_ops_setup(void)
328{
329 pv_info.name = "VMware hypervisor";
330 pv_ops.cpu.io_delay = paravirt_nop;
331
332 if (vmware_tsc_khz == 0)
333 return;
334
335 vmware_cyc2ns_setup();
336
337 if (vmw_sched_clock)
338 pv_ops.time.sched_clock = vmware_sched_clock;
339
340 if (vmware_is_stealclock_available()) {
341 has_steal_clock = true;
342 pv_ops.time.steal_clock = vmware_steal_clock;
343
344 /* We use reboot notifier only to disable steal clock */
345 register_reboot_notifier(&vmware_pv_reboot_nb);
346
347#ifdef CONFIG_SMP
348 smp_ops.smp_prepare_boot_cpu =
349 vmware_smp_prepare_boot_cpu;
350 if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
351 "x86/vmware:online",
352 vmware_cpu_online,
353 vmware_cpu_down_prepare) < 0)
354 pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n");
355#else
356 vmware_guest_cpu_init();
357#endif
358 }
359}
360#else
361#define vmware_paravirt_ops_setup() do {} while (0)
362#endif
363
364/*
365 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
366 * Still, due to timing difference when running on virtual cpus, the TSC can
367 * be marked as unstable in some cases. For example, the TSC sync check at
368 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
369 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
370 * is not suitable as a watchdog when running on a hypervisor because the
371 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
372 * long time. To skip these checks at runtime we set these capability bits,
373 * so that the kernel could just trust the hypervisor with providing a
374 * reliable virtual TSC that is suitable for timekeeping.
375 */
376static void __init vmware_set_capabilities(void)
377{
378 setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
379 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
380 if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)
381 setup_force_cpu_cap(X86_FEATURE_VMCALL);
382 else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)
383 setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL);
384}
385
386static void __init vmware_platform_setup(void)
387{
388 uint32_t eax, ebx, ecx, edx;
389 uint64_t lpj, tsc_khz;
390
391 VMWARE_CMD(GETHZ, eax, ebx, ecx, edx);
392
393 if (ebx != UINT_MAX) {
394 lpj = tsc_khz = eax | (((uint64_t)ebx) << 32);
395 do_div(tsc_khz, 1000);
396 WARN_ON(tsc_khz >> 32);
397 pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n",
398 (unsigned long) tsc_khz / 1000,
399 (unsigned long) tsc_khz % 1000);
400
401 if (!preset_lpj) {
402 do_div(lpj, HZ);
403 preset_lpj = lpj;
404 }
405
406 vmware_tsc_khz = tsc_khz;
407 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
408 x86_platform.calibrate_cpu = vmware_get_tsc_khz;
409
410#ifdef CONFIG_X86_LOCAL_APIC
411 /* Skip lapic calibration since we know the bus frequency. */
412 lapic_timer_period = ecx / HZ;
413 pr_info("Host bus clock speed read from hypervisor : %u Hz\n",
414 ecx);
415#endif
416 } else {
417 pr_warn("Failed to get TSC freq from the hypervisor\n");
418 }
419
420 vmware_paravirt_ops_setup();
421
422#ifdef CONFIG_X86_IO_APIC
423 no_timer_check = 1;
424#endif
425
426 vmware_set_capabilities();
427}
428
429static u8 __init vmware_select_hypercall(void)
430{
431 int eax, ebx, ecx, edx;
432
433 cpuid(CPUID_VMWARE_FEATURES_LEAF, &eax, &ebx, &ecx, &edx);
434 return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL |
435 CPUID_VMWARE_FEATURES_ECX_VMCALL));
436}
437
438/*
439 * While checking the dmi string information, just checking the product
440 * serial key should be enough, as this will always have a VMware
441 * specific string when running under VMware hypervisor.
442 * If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode
443 * intentionally defaults to 0.
444 */
445static uint32_t __init vmware_platform(void)
446{
447 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
448 unsigned int eax;
449 unsigned int hyper_vendor_id[3];
450
451 cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
452 &hyper_vendor_id[1], &hyper_vendor_id[2]);
453 if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) {
454 if (eax >= CPUID_VMWARE_FEATURES_LEAF)
455 vmware_hypercall_mode =
456 vmware_select_hypercall();
457
458 pr_info("hypercall mode: 0x%02x\n",
459 (unsigned int) vmware_hypercall_mode);
460
461 return CPUID_VMWARE_INFO_LEAF;
462 }
463 } else if (dmi_available && dmi_name_in_serial("VMware") &&
464 __vmware_platform())
465 return 1;
466
467 return 0;
468}
469
470/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
471static bool __init vmware_legacy_x2apic_available(void)
472{
473 uint32_t eax, ebx, ecx, edx;
474 VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
475 return (eax & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 &&
476 (eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0;
477}
478
479const __initconst struct hypervisor_x86 x86_hyper_vmware = {
480 .name = "VMware",
481 .detect = vmware_platform,
482 .type = X86_HYPER_VMWARE,
483 .init.init_platform = vmware_platform_setup,
484 .init.x2apic_available = vmware_legacy_x2apic_available,
485};