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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> | |
453dc659 | 25 | #include <linux/module.h> |
88b094fb | 26 | #include <asm/div64.h> |
2d826404 | 27 | #include <asm/x86_init.h> |
e08cae41 | 28 | #include <asm/hypervisor.h> |
88b094fb AK |
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), \ | |
6bdbfe99 | 42 | "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \ |
88b094fb AK |
43 | "memory"); |
44 | ||
45 | static 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 | ||
2d826404 | 52 | static unsigned long vmware_get_tsc_khz(void) |
88b094fb | 53 | { |
8bdbd962 AC |
54 | uint64_t tsc_hz; |
55 | uint32_t eax, ebx, ecx, edx; | |
88b094fb | 56 | |
8bdbd962 | 57 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); |
88b094fb | 58 | |
8bdbd962 AC |
59 | tsc_hz = eax | (((uint64_t)ebx) << 32); |
60 | do_div(tsc_hz, 1000); | |
61 | BUG_ON(tsc_hz >> 32); | |
6399c087 AK |
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); | |
8bdbd962 | 65 | return tsc_hz; |
88b094fb AK |
66 | } |
67 | ||
e08cae41 | 68 | static void __init vmware_platform_setup(void) |
2d826404 TG |
69 | { |
70 | uint32_t eax, ebx, ecx, edx; | |
71 | ||
72 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); | |
73 | ||
74 | if (ebx != UINT_MAX) | |
75 | x86_platform.calibrate_tsc = vmware_get_tsc_khz; | |
6399c087 AK |
76 | else |
77 | printk(KERN_WARNING | |
78 | "Failed to get TSC freq from the hypervisor\n"); | |
2d826404 TG |
79 | } |
80 | ||
fd8cd7e1 AK |
81 | /* |
82 | * While checking the dmi string infomation, just checking the product | |
83 | * serial key should be enough, as this will always have a VMware | |
84 | * specific string when running under VMware hypervisor. | |
85 | */ | |
e08cae41 | 86 | static bool __init vmware_platform(void) |
88b094fb AK |
87 | { |
88 | if (cpu_has_hypervisor) { | |
e08cae41 PA |
89 | unsigned int eax; |
90 | unsigned int hyper_vendor_id[3]; | |
91 | ||
92 | cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0], | |
93 | &hyper_vendor_id[1], &hyper_vendor_id[2]); | |
94 | if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) | |
95 | return true; | |
fd8cd7e1 | 96 | } else if (dmi_available && dmi_name_in_serial("VMware") && |
88b094fb | 97 | __vmware_platform()) |
e08cae41 | 98 | return true; |
88b094fb | 99 | |
e08cae41 | 100 | return false; |
88b094fb AK |
101 | } |
102 | ||
eca0cd02 AK |
103 | /* |
104 | * VMware hypervisor takes care of exporting a reliable TSC to the guest. | |
105 | * Still, due to timing difference when running on virtual cpus, the TSC can | |
106 | * be marked as unstable in some cases. For example, the TSC sync check at | |
107 | * bootup can fail due to a marginal offset between vcpus' TSCs (though the | |
108 | * TSCs do not drift from each other). Also, the ACPI PM timer clocksource | |
109 | * is not suitable as a watchdog when running on a hypervisor because the | |
110 | * kernel may miss a wrap of the counter if the vcpu is descheduled for a | |
111 | * long time. To skip these checks at runtime we set these capability bits, | |
112 | * so that the kernel could just trust the hypervisor with providing a | |
113 | * reliable virtual TSC that is suitable for timekeeping. | |
114 | */ | |
e08cae41 | 115 | static void __cpuinit vmware_set_cpu_features(struct cpuinfo_x86 *c) |
eca0cd02 AK |
116 | { |
117 | set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); | |
118 | set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE); | |
119 | } | |
e08cae41 PA |
120 | |
121 | const __refconst struct hypervisor_x86 x86_hyper_vmware = { | |
122 | .name = "VMware", | |
123 | .detect = vmware_platform, | |
124 | .set_cpu_features = vmware_set_cpu_features, | |
125 | .init_platform = vmware_platform_setup, | |
126 | }; | |
96f6e775 | 127 | EXPORT_SYMBOL(x86_hyper_vmware); |