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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/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#define VMWARE_PORT_CMD_GETVCPU_INFO 68
37#define VMWARE_PORT_CMD_LEGACY_X2APIC 3
38#define VMWARE_PORT_CMD_VCPU_RESERVED 31
39
40#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
41 __asm__("inl (%%dx)" : \
42 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
43 "0"(VMWARE_HYPERVISOR_MAGIC), \
44 "1"(VMWARE_PORT_CMD_##cmd), \
45 "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \
46 "memory");
47
48static inline int __vmware_platform(void)
49{
50 uint32_t eax, ebx, ecx, edx;
51 VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
52 return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
53}
54
55static unsigned long vmware_get_tsc_khz(void)
56{
57 uint64_t tsc_hz, lpj;
58 uint32_t eax, ebx, ecx, edx;
59
60 VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
61
62 tsc_hz = eax | (((uint64_t)ebx) << 32);
63 do_div(tsc_hz, 1000);
64 BUG_ON(tsc_hz >> 32);
65 pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n",
66 (unsigned long) tsc_hz / 1000,
67 (unsigned long) tsc_hz % 1000);
68
69 if (!preset_lpj) {
70 lpj = ((u64)tsc_hz * 1000);
71 do_div(lpj, HZ);
72 preset_lpj = lpj;
73 }
74
75 return tsc_hz;
76}
77
78static void __init vmware_platform_setup(void)
79{
80 uint32_t eax, ebx, ecx, edx;
81
82 VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
83
84 if (ebx != UINT_MAX)
85 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
86 else
87 pr_warn("Failed to get TSC freq from the hypervisor\n");
88}
89
90/*
91 * While checking the dmi string information, just checking the product
92 * serial key should be enough, as this will always have a VMware
93 * specific string when running under VMware hypervisor.
94 */
95static uint32_t __init vmware_platform(void)
96{
97 if (cpu_has_hypervisor) {
98 unsigned int eax;
99 unsigned int hyper_vendor_id[3];
100
101 cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
102 &hyper_vendor_id[1], &hyper_vendor_id[2]);
103 if (!memcmp(hyper_vendor_id, "VMwareVMware", 12))
104 return CPUID_VMWARE_INFO_LEAF;
105 } else if (dmi_available && dmi_name_in_serial("VMware") &&
106 __vmware_platform())
107 return 1;
108
109 return 0;
110}
111
112/*
113 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
114 * Still, due to timing difference when running on virtual cpus, the TSC can
115 * be marked as unstable in some cases. For example, the TSC sync check at
116 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
117 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
118 * is not suitable as a watchdog when running on a hypervisor because the
119 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
120 * long time. To skip these checks at runtime we set these capability bits,
121 * so that the kernel could just trust the hypervisor with providing a
122 * reliable virtual TSC that is suitable for timekeeping.
123 */
124static void vmware_set_cpu_features(struct cpuinfo_x86 *c)
125{
126 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
127 set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
128}
129
130/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
131static bool __init vmware_legacy_x2apic_available(void)
132{
133 uint32_t eax, ebx, ecx, edx;
134 VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx);
135 return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 &&
136 (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
137}
138
139const __refconst struct hypervisor_x86 x86_hyper_vmware = {
140 .name = "VMware",
141 .detect = vmware_platform,
142 .set_cpu_features = vmware_set_cpu_features,
143 .init_platform = vmware_platform_setup,
144 .x2apic_available = vmware_legacy_x2apic_available,
145};
146EXPORT_SYMBOL(x86_hyper_vmware);