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88b094fb AK |
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 <asm/div64.h> | |
c450d780 | 26 | #include <asm/vmware.h> |
2d826404 | 27 | #include <asm/x86_init.h> |
88b094fb AK |
28 | |
29 | #define CPUID_VMWARE_INFO_LEAF 0x40000000 | |
30 | #define VMWARE_HYPERVISOR_MAGIC 0x564D5868 | |
31 | #define VMWARE_HYPERVISOR_PORT 0x5658 | |
32 | ||
33 | #define VMWARE_PORT_CMD_GETVERSION 10 | |
34 | #define VMWARE_PORT_CMD_GETHZ 45 | |
35 | ||
36 | #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \ | |
37 | __asm__("inl (%%dx)" : \ | |
38 | "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ | |
39 | "0"(VMWARE_HYPERVISOR_MAGIC), \ | |
40 | "1"(VMWARE_PORT_CMD_##cmd), \ | |
6bdbfe99 | 41 | "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \ |
88b094fb AK |
42 | "memory"); |
43 | ||
44 | static inline int __vmware_platform(void) | |
45 | { | |
46 | uint32_t eax, ebx, ecx, edx; | |
47 | VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx); | |
48 | return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC; | |
49 | } | |
50 | ||
2d826404 | 51 | static unsigned long vmware_get_tsc_khz(void) |
88b094fb | 52 | { |
8bdbd962 AC |
53 | uint64_t tsc_hz; |
54 | uint32_t eax, ebx, ecx, edx; | |
88b094fb | 55 | |
8bdbd962 | 56 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); |
88b094fb | 57 | |
8bdbd962 AC |
58 | tsc_hz = eax | (((uint64_t)ebx) << 32); |
59 | do_div(tsc_hz, 1000); | |
60 | BUG_ON(tsc_hz >> 32); | |
6399c087 AK |
61 | printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n", |
62 | (unsigned long) tsc_hz / 1000, | |
63 | (unsigned long) tsc_hz % 1000); | |
8bdbd962 | 64 | return tsc_hz; |
88b094fb AK |
65 | } |
66 | ||
2d826404 TG |
67 | void __init vmware_platform_setup(void) |
68 | { | |
69 | uint32_t eax, ebx, ecx, edx; | |
70 | ||
71 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); | |
72 | ||
73 | if (ebx != UINT_MAX) | |
74 | x86_platform.calibrate_tsc = vmware_get_tsc_khz; | |
6399c087 AK |
75 | else |
76 | printk(KERN_WARNING | |
77 | "Failed to get TSC freq from the hypervisor\n"); | |
2d826404 TG |
78 | } |
79 | ||
fd8cd7e1 AK |
80 | /* |
81 | * While checking the dmi string infomation, just checking the product | |
82 | * serial key should be enough, as this will always have a VMware | |
83 | * specific string when running under VMware hypervisor. | |
84 | */ | |
88b094fb AK |
85 | int vmware_platform(void) |
86 | { | |
87 | if (cpu_has_hypervisor) { | |
88 | unsigned int eax, ebx, ecx, edx; | |
89 | char hyper_vendor_id[13]; | |
90 | ||
91 | cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &ebx, &ecx, &edx); | |
92 | memcpy(hyper_vendor_id + 0, &ebx, 4); | |
93 | memcpy(hyper_vendor_id + 4, &ecx, 4); | |
94 | memcpy(hyper_vendor_id + 8, &edx, 4); | |
95 | hyper_vendor_id[12] = '\0'; | |
96 | if (!strcmp(hyper_vendor_id, "VMwareVMware")) | |
97 | return 1; | |
fd8cd7e1 | 98 | } else if (dmi_available && dmi_name_in_serial("VMware") && |
88b094fb AK |
99 | __vmware_platform()) |
100 | return 1; | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
eca0cd02 AK |
105 | /* |
106 | * VMware hypervisor takes care of exporting a reliable TSC to the guest. | |
107 | * Still, due to timing difference when running on virtual cpus, the TSC can | |
108 | * be marked as unstable in some cases. For example, the TSC sync check at | |
109 | * bootup can fail due to a marginal offset between vcpus' TSCs (though the | |
110 | * TSCs do not drift from each other). Also, the ACPI PM timer clocksource | |
111 | * is not suitable as a watchdog when running on a hypervisor because the | |
112 | * kernel may miss a wrap of the counter if the vcpu is descheduled for a | |
113 | * long time. To skip these checks at runtime we set these capability bits, | |
114 | * so that the kernel could just trust the hypervisor with providing a | |
115 | * reliable virtual TSC that is suitable for timekeeping. | |
116 | */ | |
117 | void __cpuinit vmware_set_feature_bits(struct cpuinfo_x86 *c) | |
118 | { | |
119 | set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); | |
120 | set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE); | |
121 | } |