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linux/linux-5.4.31/arch/x86/kernel/cpu/vmware.c

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/*
* 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>
#include <asm/vmware.h>
#undef pr_fmt
#define pr_fmt(fmt) "vmware: " fmt
#define CPUID_VMWARE_INFO_LEAF 0x40000000
#define CPUID_VMWARE_FEATURES_LEAF 0x40000010
#define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0)
#define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1)
#define VMWARE_HYPERVISOR_MAGIC 0x564D5868
#define VMWARE_CMD_GETVERSION 10
#define VMWARE_CMD_GETHZ 45
#define VMWARE_CMD_GETVCPU_INFO 68
#define VMWARE_CMD_LEGACY_X2APIC 3
#define VMWARE_CMD_VCPU_RESERVED 31
#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
__asm__("inl (%%dx), %%eax" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \
"memory")
#define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \
__asm__("vmcall" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(0), "b"(UINT_MAX) : \
"memory")
#define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \
__asm__("vmmcall" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(0), "b"(UINT_MAX) : \
"memory")
#define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \
switch (vmware_hypercall_mode) { \
case CPUID_VMWARE_FEATURES_ECX_VMCALL: \
VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \
break; \
case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \
VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \
break; \
default: \
VMWARE_PORT(cmd, eax, ebx, ecx, edx); \
break; \
} \
} while (0)
static unsigned long vmware_tsc_khz __ro_after_init;
static u8 vmware_hypercall_mode __ro_after_init;
static inline int __vmware_platform(void)
{
uint32_t eax, ebx, ecx, edx;
VMWARE_CMD(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_ops.time.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_ops.cpu.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);
if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)
setup_force_cpu_cap(X86_FEATURE_VMCALL);
else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)
setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL);
}
static void __init vmware_platform_setup(void)
{
uint32_t eax, ebx, ecx, edx;
uint64_t lpj, tsc_khz;
VMWARE_CMD(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_period = 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();
}
static u8 vmware_select_hypercall(void)
{
int eax, ebx, ecx, edx;
cpuid(CPUID_VMWARE_FEATURES_LEAF, &eax, &ebx, &ecx, &edx);
return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL |
CPUID_VMWARE_FEATURES_ECX_VMCALL));
}
/*
* 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.
* If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode
* intentionally defaults to 0.
*/
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)) {
if (eax >= CPUID_VMWARE_FEATURES_LEAF)
vmware_hypercall_mode =
vmware_select_hypercall();
pr_info("hypercall mode: 0x%02x\n",
(unsigned int) vmware_hypercall_mode);
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_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
return (eax & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 &&
(eax & (1 << VMWARE_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,
};
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