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Diffstat (limited to 'arch/x86/kernel/cpu/vmware.c')
| -rw-r--r-- | arch/x86/kernel/cpu/vmware.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c new file mode 100644 index 000000000..d805202c6 --- /dev/null +++ b/arch/x86/kernel/cpu/vmware.c @@ -0,0 +1,214 @@ +/* + * VMware Detection code. + * + * Copyright (C) 2008, VMware, Inc. + * Author : Alok N Kataria <akataria@vmware.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +#include <linux/dmi.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/clocksource.h> +#include <asm/div64.h> +#include <asm/x86_init.h> +#include <asm/hypervisor.h> +#include <asm/timer.h> +#include <asm/apic.h> + +#undef pr_fmt +#define pr_fmt(fmt) "vmware: " fmt + +#define CPUID_VMWARE_INFO_LEAF 0x40000000 +#define VMWARE_HYPERVISOR_MAGIC 0x564D5868 +#define VMWARE_HYPERVISOR_PORT 0x5658 + +#define VMWARE_PORT_CMD_GETVERSION 10 +#define VMWARE_PORT_CMD_GETHZ 45 +#define VMWARE_PORT_CMD_GETVCPU_INFO 68 +#define VMWARE_PORT_CMD_LEGACY_X2APIC 3 +#define VMWARE_PORT_CMD_VCPU_RESERVED 31 + +#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \ + __asm__("inl (%%dx)" : \ + "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ + "0"(VMWARE_HYPERVISOR_MAGIC), \ + "1"(VMWARE_PORT_CMD_##cmd), \ + "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \ + "memory"); + +static unsigned long vmware_tsc_khz __ro_after_init; + +static inline int __vmware_platform(void) +{ + uint32_t eax, ebx, ecx, edx; + VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx); + return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC; +} + +static unsigned long vmware_get_tsc_khz(void) +{ + return vmware_tsc_khz; +} + +#ifdef CONFIG_PARAVIRT +static struct cyc2ns_data vmware_cyc2ns __ro_after_init; +static int vmw_sched_clock __initdata = 1; + +static __init int setup_vmw_sched_clock(char *s) +{ + vmw_sched_clock = 0; + return 0; +} +early_param("no-vmw-sched-clock", setup_vmw_sched_clock); + +static unsigned long long notrace vmware_sched_clock(void) +{ + unsigned long long ns; + + ns = mul_u64_u32_shr(rdtsc(), vmware_cyc2ns.cyc2ns_mul, + vmware_cyc2ns.cyc2ns_shift); + ns -= vmware_cyc2ns.cyc2ns_offset; + return ns; +} + +static void __init vmware_sched_clock_setup(void) +{ + struct cyc2ns_data *d = &vmware_cyc2ns; + unsigned long long tsc_now = rdtsc(); + + clocks_calc_mult_shift(&d->cyc2ns_mul, &d->cyc2ns_shift, + vmware_tsc_khz, NSEC_PER_MSEC, 0); + d->cyc2ns_offset = mul_u64_u32_shr(tsc_now, d->cyc2ns_mul, + d->cyc2ns_shift); + + pv_time_ops.sched_clock = vmware_sched_clock; + pr_info("using sched offset of %llu ns\n", d->cyc2ns_offset); +} + +static void __init vmware_paravirt_ops_setup(void) +{ + pv_info.name = "VMware hypervisor"; + pv_cpu_ops.io_delay = paravirt_nop; + + if (vmware_tsc_khz && vmw_sched_clock) + vmware_sched_clock_setup(); +} +#else +#define vmware_paravirt_ops_setup() do {} while (0) +#endif + +/* + * VMware hypervisor takes care of exporting a reliable TSC to the guest. + * Still, due to timing difference when running on virtual cpus, the TSC can + * be marked as unstable in some cases. For example, the TSC sync check at + * bootup can fail due to a marginal offset between vcpus' TSCs (though the + * TSCs do not drift from each other). Also, the ACPI PM timer clocksource + * is not suitable as a watchdog when running on a hypervisor because the + * kernel may miss a wrap of the counter if the vcpu is descheduled for a + * long time. To skip these checks at runtime we set these capability bits, + * so that the kernel could just trust the hypervisor with providing a + * reliable virtual TSC that is suitable for timekeeping. + */ +static void __init vmware_set_capabilities(void) +{ + setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC); + setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE); +} + +static void __init vmware_platform_setup(void) +{ + uint32_t eax, ebx, ecx, edx; + uint64_t lpj, tsc_khz; + + VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); + + if (ebx != UINT_MAX) { + lpj = tsc_khz = eax | (((uint64_t)ebx) << 32); + do_div(tsc_khz, 1000); + WARN_ON(tsc_khz >> 32); + pr_info("TSC freq read from hypervisor : %lu.%03lu MHz\n", + (unsigned long) tsc_khz / 1000, + (unsigned long) tsc_khz % 1000); + + if (!preset_lpj) { + do_div(lpj, HZ); + preset_lpj = lpj; + } + + vmware_tsc_khz = tsc_khz; + x86_platform.calibrate_tsc = vmware_get_tsc_khz; + x86_platform.calibrate_cpu = vmware_get_tsc_khz; + +#ifdef CONFIG_X86_LOCAL_APIC + /* Skip lapic calibration since we know the bus frequency. */ + lapic_timer_frequency = ecx / HZ; + pr_info("Host bus clock speed read from hypervisor : %u Hz\n", + ecx); +#endif + } else { + pr_warn("Failed to get TSC freq from the hypervisor\n"); + } + + vmware_paravirt_ops_setup(); + +#ifdef CONFIG_X86_IO_APIC + no_timer_check = 1; +#endif + + vmware_set_capabilities(); +} + +/* + * While checking the dmi string information, just checking the product + * serial key should be enough, as this will always have a VMware + * specific string when running under VMware hypervisor. + */ +static uint32_t __init vmware_platform(void) +{ + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { + unsigned int eax; + unsigned int hyper_vendor_id[3]; + + cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0], + &hyper_vendor_id[1], &hyper_vendor_id[2]); + if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) + return CPUID_VMWARE_INFO_LEAF; + } else if (dmi_available && dmi_name_in_serial("VMware") && + __vmware_platform()) + return 1; + + return 0; +} + +/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */ +static bool __init vmware_legacy_x2apic_available(void) +{ + uint32_t eax, ebx, ecx, edx; + VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx); + return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 && + (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0; +} + +const __initconst struct hypervisor_x86 x86_hyper_vmware = { + .name = "VMware", + .detect = vmware_platform, + .type = X86_HYPER_VMWARE, + .init.init_platform = vmware_platform_setup, + .init.x2apic_available = vmware_legacy_x2apic_available, +}; |