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 <asm/div64.h>
29 #include <asm/x86_init.h>
30 #include <asm/hypervisor.h>
31 #include <asm/timer.h>
32 #include <asm/apic.h>
33
34 #undef pr_fmt
35 #define pr_fmt(fmt) "vmware: " fmt
36
37 #define CPUID_VMWARE_INFO_LEAF 0x40000000
38 #define VMWARE_HYPERVISOR_MAGIC 0x564D5868
39 #define VMWARE_HYPERVISOR_PORT 0x5658
40
41 #define VMWARE_PORT_CMD_GETVERSION 10
42 #define VMWARE_PORT_CMD_GETHZ 45
43 #define VMWARE_PORT_CMD_GETVCPU_INFO 68
44 #define VMWARE_PORT_CMD_LEGACY_X2APIC 3
45 #define VMWARE_PORT_CMD_VCPU_RESERVED 31
46
47 #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
48 __asm__("inl (%%dx)" : \
49 "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
50 "0"(VMWARE_HYPERVISOR_MAGIC), \
51 "1"(VMWARE_PORT_CMD_##cmd), \
52 "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \
53 "memory");
54
55 static unsigned long vmware_tsc_khz __ro_after_init;
56
__vmware_platform(void)57 static inline int __vmware_platform(void)
58 {
59 uint32_t eax, ebx, ecx, edx;
60 VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
61 return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
62 }
63
vmware_get_tsc_khz(void)64 static unsigned long vmware_get_tsc_khz(void)
65 {
66 return vmware_tsc_khz;
67 }
68
69 #ifdef CONFIG_PARAVIRT
70 static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
71 static int vmw_sched_clock __initdata = 1;
72
setup_vmw_sched_clock(char * s)73 static __init int setup_vmw_sched_clock(char *s)
74 {
75 vmw_sched_clock = 0;
76 return 0;
77 }
78 early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
79
vmware_sched_clock(void)80 static unsigned long long vmware_sched_clock(void)
81 {
82 unsigned long long ns;
83
84 ns = mul_u64_u32_shr(rdtsc(), vmware_cyc2ns.cyc2ns_mul,
85 vmware_cyc2ns.cyc2ns_shift);
86 ns -= vmware_cyc2ns.cyc2ns_offset;
87 return ns;
88 }
89
vmware_sched_clock_setup(void)90 static void __init vmware_sched_clock_setup(void)
91 {
92 struct cyc2ns_data *d = &vmware_cyc2ns;
93 unsigned long long tsc_now = rdtsc();
94
95 clocks_calc_mult_shift(&d->cyc2ns_mul, &d->cyc2ns_shift,
96 vmware_tsc_khz, NSEC_PER_MSEC, 0);
97 d->cyc2ns_offset = mul_u64_u32_shr(tsc_now, d->cyc2ns_mul,
98 d->cyc2ns_shift);
99
100 pv_time_ops.sched_clock = vmware_sched_clock;
101 pr_info("using sched offset of %llu ns\n", d->cyc2ns_offset);
102 }
103
vmware_paravirt_ops_setup(void)104 static void __init vmware_paravirt_ops_setup(void)
105 {
106 pv_info.name = "VMware hypervisor";
107 pv_cpu_ops.io_delay = paravirt_nop;
108
109 if (vmware_tsc_khz && vmw_sched_clock)
110 vmware_sched_clock_setup();
111 }
112 #else
113 #define vmware_paravirt_ops_setup() do {} while (0)
114 #endif
115
116 /*
117 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
118 * Still, due to timing difference when running on virtual cpus, the TSC can
119 * be marked as unstable in some cases. For example, the TSC sync check at
120 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
121 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
122 * is not suitable as a watchdog when running on a hypervisor because the
123 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
124 * long time. To skip these checks at runtime we set these capability bits,
125 * so that the kernel could just trust the hypervisor with providing a
126 * reliable virtual TSC that is suitable for timekeeping.
127 */
vmware_set_capabilities(void)128 static void __init vmware_set_capabilities(void)
129 {
130 setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
131 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
132 }
133
vmware_platform_setup(void)134 static void __init vmware_platform_setup(void)
135 {
136 uint32_t eax, ebx, ecx, edx;
137 uint64_t lpj, tsc_khz;
138
139 VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
140
141 if (ebx != UINT_MAX) {
142 lpj = tsc_khz = eax | (((uint64_t)ebx) << 32);
143 do_div(tsc_khz, 1000);
144 WARN_ON(tsc_khz >> 32);
145 pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n",
146 (unsigned long) tsc_khz / 1000,
147 (unsigned long) tsc_khz % 1000);
148
149 if (!preset_lpj) {
150 do_div(lpj, HZ);
151 preset_lpj = lpj;
152 }
153
154 vmware_tsc_khz = tsc_khz;
155 x86_platform.calibrate_tsc = vmware_get_tsc_khz;
156 x86_platform.calibrate_cpu = vmware_get_tsc_khz;
157
158 #ifdef CONFIG_X86_LOCAL_APIC
159 /* Skip lapic calibration since we know the bus frequency. */
160 lapic_timer_frequency = ecx / HZ;
161 pr_info("Host bus clock speed read from hypervisor : %u Hz\n",
162 ecx);
163 #endif
164 } else {
165 pr_warn("Failed to get TSC freq from the hypervisor\n");
166 }
167
168 vmware_paravirt_ops_setup();
169
170 #ifdef CONFIG_X86_IO_APIC
171 no_timer_check = 1;
172 #endif
173
174 vmware_set_capabilities();
175 }
176
177 /*
178 * While checking the dmi string information, just checking the product
179 * serial key should be enough, as this will always have a VMware
180 * specific string when running under VMware hypervisor.
181 */
vmware_platform(void)182 static uint32_t __init vmware_platform(void)
183 {
184 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
185 unsigned int eax;
186 unsigned int hyper_vendor_id[3];
187
188 cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
189 &hyper_vendor_id[1], &hyper_vendor_id[2]);
190 if (!memcmp(hyper_vendor_id, "VMwareVMware", 12))
191 return CPUID_VMWARE_INFO_LEAF;
192 } else if (dmi_available && dmi_name_in_serial("VMware") &&
193 __vmware_platform())
194 return 1;
195
196 return 0;
197 }
198
199 /* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
vmware_legacy_x2apic_available(void)200 static bool __init vmware_legacy_x2apic_available(void)
201 {
202 uint32_t eax, ebx, ecx, edx;
203 VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx);
204 return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 &&
205 (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
206 }
207
208 const __initconst struct hypervisor_x86 x86_hyper_vmware = {
209 .name = "VMware",
210 .detect = vmware_platform,
211 .type = X86_HYPER_VMWARE,
212 .init.init_platform = vmware_platform_setup,
213 .init.x2apic_available = vmware_legacy_x2apic_available,
214 };
215
