arch/x86/kernel/cpu/vmware.c - linux - Git at Google

 /*
  * 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 <linux/cpu.h>
 #include <linux/reboot.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_CMD_STEALCLOCK    91

 #define STEALCLOCK_NOT_AVAILABLE (-1)
 #define STEALCLOCK_DISABLED        0
 #define STEALCLOCK_ENABLED         1

 #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)

 struct vmware_steal_time {
 	union {
 		uint64_t clock;	/* stolen time counter in units of vtsc */
 		struct {
 			/* only for little-endian */
 			uint32_t clock_low;
 			uint32_t clock_high;
 		};
 	};
 	uint64_t reserved[7];
 };

 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 bool vmw_sched_clock __initdata = true;
 static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
 static bool has_steal_clock;
 static bool steal_acc __initdata = true; /* steal time accounting */

 static __init int setup_vmw_sched_clock(char *s)
 {
 	vmw_sched_clock = false;
 	return 0;
 }
 early_param("no-vmw-sched-clock", setup_vmw_sched_clock);

 static __init int parse_no_stealacc(char *arg)
 {
 	steal_acc = false;
 	return 0;
 }
 early_param("no-steal-acc", parse_no_stealacc);

 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_cyc2ns_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);

 	pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset);
 }

 static int vmware_cmd_stealclock(uint32_t arg1, uint32_t arg2)
 {
 	uint32_t result, info;

 	asm volatile (VMWARE_HYPERCALL :
 		"=a"(result),
 		"=c"(info) :
 		"a"(VMWARE_HYPERVISOR_MAGIC),
 		"b"(0),
 		"c"(VMWARE_CMD_STEALCLOCK),
 		"d"(0),
 		"S"(arg1),
 		"D"(arg2) :
 		"memory");
 	return result;
 }

 static bool stealclock_enable(phys_addr_t pa)
 {
 	return vmware_cmd_stealclock(upper_32_bits(pa),
 				     lower_32_bits(pa)) == STEALCLOCK_ENABLED;
 }

 static int __stealclock_disable(void)
 {
 	return vmware_cmd_stealclock(0, 1);
 }

 static void stealclock_disable(void)
 {
 	__stealclock_disable();
 }

 static bool vmware_is_stealclock_available(void)
 {
 	return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE;
 }

 /**
  * vmware_steal_clock() - read the per-cpu steal clock
  * @cpu:            the cpu number whose steal clock we want to read
  *
  * The function reads the steal clock if we are on a 64-bit system, otherwise
  * reads it in parts, checking that the high part didn't change in the
  * meantime.
  *
  * Return:
  *      The steal clock reading in ns.
  */
 static uint64_t vmware_steal_clock(int cpu)
 {
 	struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu);
 	uint64_t clock;

 	if (IS_ENABLED(CONFIG_64BIT))
 		clock = READ_ONCE(steal->clock);
 	else {
 		uint32_t initial_high, low, high;

 		do {
 			initial_high = READ_ONCE(steal->clock_high);
 			/* Do not reorder initial_high and high readings */
 			virt_rmb();
 			low = READ_ONCE(steal->clock_low);
 			/* Keep low reading in between */
 			virt_rmb();
 			high = READ_ONCE(steal->clock_high);
 		} while (initial_high != high);

 		clock = ((uint64_t)high << 32) | low;
 	}

 	return mul_u64_u32_shr(clock, vmware_cyc2ns.cyc2ns_mul,
 			     vmware_cyc2ns.cyc2ns_shift);
 }

 static void vmware_register_steal_time(void)
 {
 	int cpu = smp_processor_id();
 	struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu);

 	if (!has_steal_clock)
 		return;

 	if (!stealclock_enable(slow_virt_to_phys(st))) {
 		has_steal_clock = false;
 		return;
 	}

 	pr_info("vmware-stealtime: cpu %d, pa %llx\n",
 		cpu, (unsigned long long) slow_virt_to_phys(st));
 }

 static void vmware_disable_steal_time(void)
 {
 	if (!has_steal_clock)
 		return;

 	stealclock_disable();
 }

 static void vmware_guest_cpu_init(void)
 {
 	if (has_steal_clock)
 		vmware_register_steal_time();
 }

 static void vmware_pv_guest_cpu_reboot(void *unused)
 {
 	vmware_disable_steal_time();
 }

 static int vmware_pv_reboot_notify(struct notifier_block *nb,
 				unsigned long code, void *unused)
 {
 	if (code == SYS_RESTART)
 		on_each_cpu(vmware_pv_guest_cpu_reboot, NULL, 1);
 	return NOTIFY_DONE;
 }

 static struct notifier_block vmware_pv_reboot_nb = {
 	.notifier_call = vmware_pv_reboot_notify,
 };

 #ifdef CONFIG_SMP
 static void __init vmware_smp_prepare_boot_cpu(void)
 {
 	vmware_guest_cpu_init();
 	native_smp_prepare_boot_cpu();
 }

 static int vmware_cpu_online(unsigned int cpu)
 {
 	local_irq_disable();
 	vmware_guest_cpu_init();
 	local_irq_enable();
 	return 0;
 }

 static int vmware_cpu_down_prepare(unsigned int cpu)
 {
 	local_irq_disable();
 	vmware_disable_steal_time();
 	local_irq_enable();
 	return 0;
 }
 #endif

 static __init int activate_jump_labels(void)
 {
 	if (has_steal_clock) {
 		static_key_slow_inc(&paravirt_steal_enabled);
 		if (steal_acc)
 			static_key_slow_inc(&paravirt_steal_rq_enabled);
 	}

 	return 0;
 }
 arch_initcall(activate_jump_labels);

 static void __init vmware_paravirt_ops_setup(void)
 {
 	pv_info.name = "VMware hypervisor";
 	pv_ops.cpu.io_delay = paravirt_nop;

 	if (vmware_tsc_khz == 0)
 		return;

 	vmware_cyc2ns_setup();

 	if (vmw_sched_clock)
 		pv_ops.time.sched_clock = vmware_sched_clock;

 	if (vmware_is_stealclock_available()) {
 		has_steal_clock = true;
 		pv_ops.time.steal_clock = vmware_steal_clock;

 		/* We use reboot notifier only to disable steal clock */
 		register_reboot_notifier(&vmware_pv_reboot_nb);

 #ifdef CONFIG_SMP
 		smp_ops.smp_prepare_boot_cpu =
 			vmware_smp_prepare_boot_cpu;
 		if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
 					      "x86/vmware:online",
 					      vmware_cpu_online,
 					      vmware_cpu_down_prepare) < 0)
 			pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n");
 #else
 		vmware_guest_cpu_init();
 #endif
 	}
 }
 #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 __init 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,
 };
	/*
	* 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 <linux/cpu.h>
	#include <linux/reboot.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_CMD_STEALCLOCK 91

	#define STEALCLOCK_NOT_AVAILABLE (-1)
	#define STEALCLOCK_DISABLED 0
	#define STEALCLOCK_ENABLED 1

	#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)

	struct vmware_steal_time {
	union {
	uint64_t clock; /* stolen time counter in units of vtsc */
	struct {
	/* only for little-endian */
	uint32_t clock_low;
	uint32_t clock_high;
	};
	};
	uint64_t reserved[7];
	};

	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 bool vmw_sched_clock __initdata = true;
	static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
	static bool has_steal_clock;
	static bool steal_acc __initdata = true; /* steal time accounting */

	static __init int setup_vmw_sched_clock(char *s)
	{
	vmw_sched_clock = false;
	return 0;
	}
	early_param("no-vmw-sched-clock", setup_vmw_sched_clock);

	static __init int parse_no_stealacc(char *arg)
	{
	steal_acc = false;
	return 0;
	}
	early_param("no-steal-acc", parse_no_stealacc);

	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_cyc2ns_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);

	pr_info("using clock offset of %llu ns\n", d->cyc2ns_offset);
	}

	static int vmware_cmd_stealclock(uint32_t arg1, uint32_t arg2)
	{
	uint32_t result, info;

	asm volatile (VMWARE_HYPERCALL :
	"=a"(result),
	"=c"(info) :
	"a"(VMWARE_HYPERVISOR_MAGIC),
	"b"(0),
	"c"(VMWARE_CMD_STEALCLOCK),
	"d"(0),
	"S"(arg1),
	"D"(arg2) :
	"memory");
	return result;
	}

	static bool stealclock_enable(phys_addr_t pa)
	{
	return vmware_cmd_stealclock(upper_32_bits(pa),
	lower_32_bits(pa)) == STEALCLOCK_ENABLED;
	}

	static int __stealclock_disable(void)
	{
	return vmware_cmd_stealclock(0, 1);
	}

	static void stealclock_disable(void)
	{
	__stealclock_disable();
	}

	static bool vmware_is_stealclock_available(void)
	{
	return __stealclock_disable() != STEALCLOCK_NOT_AVAILABLE;
	}

	/**
	* vmware_steal_clock() - read the per-cpu steal clock
	* @cpu: the cpu number whose steal clock we want to read
	*
	* The function reads the steal clock if we are on a 64-bit system, otherwise
	* reads it in parts, checking that the high part didn't change in the
	* meantime.
	*
	* Return:
	* The steal clock reading in ns.
	*/
	static uint64_t vmware_steal_clock(int cpu)
	{
	struct vmware_steal_time *steal = &per_cpu(vmw_steal_time, cpu);
	uint64_t clock;

	if (IS_ENABLED(CONFIG_64BIT))
	clock = READ_ONCE(steal->clock);
	else {
	uint32_t initial_high, low, high;

	do {
	initial_high = READ_ONCE(steal->clock_high);
	/* Do not reorder initial_high and high readings */
	virt_rmb();
	low = READ_ONCE(steal->clock_low);
	/* Keep low reading in between */
	virt_rmb();
	high = READ_ONCE(steal->clock_high);
	} while (initial_high != high);

	clock = ((uint64_t)high << 32) \| low;
	}

	return mul_u64_u32_shr(clock, vmware_cyc2ns.cyc2ns_mul,
	vmware_cyc2ns.cyc2ns_shift);
	}

	static void vmware_register_steal_time(void)
	{
	int cpu = smp_processor_id();
	struct vmware_steal_time *st = &per_cpu(vmw_steal_time, cpu);

	if (!has_steal_clock)
	return;

	if (!stealclock_enable(slow_virt_to_phys(st))) {
	has_steal_clock = false;
	return;
	}

	pr_info("vmware-stealtime: cpu %d, pa %llx\n",
	cpu, (unsigned long long) slow_virt_to_phys(st));
	}

	static void vmware_disable_steal_time(void)
	{
	if (!has_steal_clock)
	return;

	stealclock_disable();
	}

	static void vmware_guest_cpu_init(void)
	{
	if (has_steal_clock)
	vmware_register_steal_time();
	}

	static void vmware_pv_guest_cpu_reboot(void *unused)
	{
	vmware_disable_steal_time();
	}

	static int vmware_pv_reboot_notify(struct notifier_block *nb,
	unsigned long code, void *unused)
	{
	if (code == SYS_RESTART)
	on_each_cpu(vmware_pv_guest_cpu_reboot, NULL, 1);
	return NOTIFY_DONE;
	}

	static struct notifier_block vmware_pv_reboot_nb = {
	.notifier_call = vmware_pv_reboot_notify,
	};

	#ifdef CONFIG_SMP
	static void __init vmware_smp_prepare_boot_cpu(void)
	{
	vmware_guest_cpu_init();
	native_smp_prepare_boot_cpu();
	}

	static int vmware_cpu_online(unsigned int cpu)
	{
	local_irq_disable();
	vmware_guest_cpu_init();
	local_irq_enable();
	return 0;
	}

	static int vmware_cpu_down_prepare(unsigned int cpu)
	{
	local_irq_disable();
	vmware_disable_steal_time();
	local_irq_enable();
	return 0;
	}
	#endif

	static __init int activate_jump_labels(void)
	{
	if (has_steal_clock) {
	static_key_slow_inc(&paravirt_steal_enabled);
	if (steal_acc)
	static_key_slow_inc(&paravirt_steal_rq_enabled);
	}

	return 0;
	}
	arch_initcall(activate_jump_labels);

	static void __init vmware_paravirt_ops_setup(void)
	{
	pv_info.name = "VMware hypervisor";
	pv_ops.cpu.io_delay = paravirt_nop;

	if (vmware_tsc_khz == 0)
	return;

	vmware_cyc2ns_setup();

	if (vmw_sched_clock)
	pv_ops.time.sched_clock = vmware_sched_clock;

	if (vmware_is_stealclock_available()) {
	has_steal_clock = true;
	pv_ops.time.steal_clock = vmware_steal_clock;

	/* We use reboot notifier only to disable steal clock */
	register_reboot_notifier(&vmware_pv_reboot_nb);

	#ifdef CONFIG_SMP
	smp_ops.smp_prepare_boot_cpu =
	vmware_smp_prepare_boot_cpu;
	if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
	"x86/vmware:online",
	vmware_cpu_online,
	vmware_cpu_down_prepare) < 0)
	pr_err("vmware_guest: Failed to install cpu hotplug callbacks\n");
	#else
	vmware_guest_cpu_init();
	#endif
	}
	}
	#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 __init 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,
	};