diff options
Diffstat (limited to 'arch/x86/kernel/cpu/vmware.c')
-rw-r--r-- | arch/x86/kernel/cpu/vmware.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c new file mode 100644 index 000000000000..284c399e3234 --- /dev/null +++ b/arch/x86/kernel/cpu/vmware.c | |||
@@ -0,0 +1,112 @@ | |||
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> | ||
26 | #include <asm/vmware.h> | ||
27 | |||
28 | #define CPUID_VMWARE_INFO_LEAF 0x40000000 | ||
29 | #define VMWARE_HYPERVISOR_MAGIC 0x564D5868 | ||
30 | #define VMWARE_HYPERVISOR_PORT 0x5658 | ||
31 | |||
32 | #define VMWARE_PORT_CMD_GETVERSION 10 | ||
33 | #define VMWARE_PORT_CMD_GETHZ 45 | ||
34 | |||
35 | #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \ | ||
36 | __asm__("inl (%%dx)" : \ | ||
37 | "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ | ||
38 | "0"(VMWARE_HYPERVISOR_MAGIC), \ | ||
39 | "1"(VMWARE_PORT_CMD_##cmd), \ | ||
40 | "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \ | ||
41 | "memory"); | ||
42 | |||
43 | static inline int __vmware_platform(void) | ||
44 | { | ||
45 | uint32_t eax, ebx, ecx, edx; | ||
46 | VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx); | ||
47 | return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC; | ||
48 | } | ||
49 | |||
50 | static unsigned long __vmware_get_tsc_khz(void) | ||
51 | { | ||
52 | uint64_t tsc_hz; | ||
53 | uint32_t eax, ebx, ecx, edx; | ||
54 | |||
55 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); | ||
56 | |||
57 | if (ebx == UINT_MAX) | ||
58 | return 0; | ||
59 | tsc_hz = eax | (((uint64_t)ebx) << 32); | ||
60 | do_div(tsc_hz, 1000); | ||
61 | BUG_ON(tsc_hz >> 32); | ||
62 | return tsc_hz; | ||
63 | } | ||
64 | |||
65 | /* | ||
66 | * While checking the dmi string infomation, just checking the product | ||
67 | * serial key should be enough, as this will always have a VMware | ||
68 | * specific string when running under VMware hypervisor. | ||
69 | */ | ||
70 | int vmware_platform(void) | ||
71 | { | ||
72 | if (cpu_has_hypervisor) { | ||
73 | unsigned int eax, ebx, ecx, edx; | ||
74 | char hyper_vendor_id[13]; | ||
75 | |||
76 | cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &ebx, &ecx, &edx); | ||
77 | memcpy(hyper_vendor_id + 0, &ebx, 4); | ||
78 | memcpy(hyper_vendor_id + 4, &ecx, 4); | ||
79 | memcpy(hyper_vendor_id + 8, &edx, 4); | ||
80 | hyper_vendor_id[12] = '\0'; | ||
81 | if (!strcmp(hyper_vendor_id, "VMwareVMware")) | ||
82 | return 1; | ||
83 | } else if (dmi_available && dmi_name_in_serial("VMware") && | ||
84 | __vmware_platform()) | ||
85 | return 1; | ||
86 | |||
87 | return 0; | ||
88 | } | ||
89 | |||
90 | unsigned long vmware_get_tsc_khz(void) | ||
91 | { | ||
92 | BUG_ON(!vmware_platform()); | ||
93 | return __vmware_get_tsc_khz(); | ||
94 | } | ||
95 | |||
96 | /* | ||
97 | * VMware hypervisor takes care of exporting a reliable TSC to the guest. | ||
98 | * Still, due to timing difference when running on virtual cpus, the TSC can | ||
99 | * be marked as unstable in some cases. For example, the TSC sync check at | ||
100 | * bootup can fail due to a marginal offset between vcpus' TSCs (though the | ||
101 | * TSCs do not drift from each other). Also, the ACPI PM timer clocksource | ||
102 | * is not suitable as a watchdog when running on a hypervisor because the | ||
103 | * kernel may miss a wrap of the counter if the vcpu is descheduled for a | ||
104 | * long time. To skip these checks at runtime we set these capability bits, | ||
105 | * so that the kernel could just trust the hypervisor with providing a | ||
106 | * reliable virtual TSC that is suitable for timekeeping. | ||
107 | */ | ||
108 | void __cpuinit vmware_set_feature_bits(struct cpuinfo_x86 *c) | ||
109 | { | ||
110 | set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); | ||
111 | set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE); | ||
112 | } | ||