[deliverable/linux.git] / arch / x86 / kernel / cpu / vmware.c

/*
 * 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/module.h>
#include <asm/div64.h>
#include <asm/x86_init.h>
#include <asm/hypervisor.h>

#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, 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 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)
{
	uint64_t tsc_hz;
	uint32_t eax, ebx, ecx, edx;

	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);

	tsc_hz = eax | (((uint64_t)ebx) << 32);
	do_div(tsc_hz, 1000);
	BUG_ON(tsc_hz >> 32);
	printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n",
			 (unsigned long) tsc_hz / 1000,
			 (unsigned long) tsc_hz % 1000);
	return tsc_hz;
}

static void __init vmware_platform_setup(void)
{
	uint32_t eax, ebx, ecx, edx;

	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);

	if (ebx != UINT_MAX)
		x86_platform.calibrate_tsc = vmware_get_tsc_khz;
	else
		printk(KERN_WARNING
		       "Failed to get TSC freq from the hypervisor\n");
}

/*
 * While checking the dmi string infomation, just checking the product
 * serial key should be enough, as this will always have a VMware
 * specific string when running under VMware hypervisor.
 */
static bool __init vmware_platform(void)
{
	if (cpu_has_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 true;
	} else if (dmi_available && dmi_name_in_serial("VMware") &&
		   __vmware_platform())
		return true;

	return false;
}

/*
 * 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 __cpuinit vmware_set_cpu_features(struct cpuinfo_x86 *c)
{
	set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
	set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
}

const __refconst struct hypervisor_x86 x86_hyper_vmware = {
	.name			= "VMware",
	.detect			= vmware_platform,
	.set_cpu_features	= vmware_set_cpu_features,
	.init_platform		= vmware_platform_setup,
};
EXPORT_SYMBOL(x86_hyper_vmware);
Commit	Line	Data
88b094fb AK	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>
453dc659	25	#include <linux/module.h>
88b094fb	26	#include <asm/div64.h>
2d826404	27	#include <asm/x86_init.h>
e08cae41	28	#include <asm/hypervisor.h>
88b094fb AK	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), \
6bdbfe99	42	"2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \
88b094fb AK	43	"memory");
	44
	45	static 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
2d826404	52	static unsigned long vmware_get_tsc_khz(void)
88b094fb	53	{
8bdbd962 AC	54	uint64_t tsc_hz;
8bdbd962 AC	55	uint32_t eax, ebx, ecx, edx;
88b094fb	56
8bdbd962	57	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
88b094fb	58
8bdbd962 AC	59	tsc_hz = eax \| (((uint64_t)ebx) << 32);
	60	do_div(tsc_hz, 1000);
	61	BUG_ON(tsc_hz >> 32);
6399c087 AK	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);
8bdbd962	65	return tsc_hz;
88b094fb AK	66	}
88b094fb AK	67
e08cae41	68	static void __init vmware_platform_setup(void)
2d826404 TG	69	{
	70	uint32_t eax, ebx, ecx, edx;
	71
	72	VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
	73
	74	if (ebx != UINT_MAX)
	75	x86_platform.calibrate_tsc = vmware_get_tsc_khz;
6399c087 AK	76	else
	77	printk(KERN_WARNING
	78	"Failed to get TSC freq from the hypervisor\n");
2d826404 TG	79	}
2d826404 TG	80
fd8cd7e1 AK	81	/*
	82	* While checking the dmi string infomation, just checking the product
	83	* serial key should be enough, as this will always have a VMware
	84	* specific string when running under VMware hypervisor.
	85	*/
e08cae41	86	static bool __init vmware_platform(void)
88b094fb AK	87	{
88b094fb AK	88	if (cpu_has_hypervisor) {
e08cae41 PA	89	unsigned int eax;
	90	unsigned int hyper_vendor_id[3];
	91
	92	cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0],
	93	&hyper_vendor_id[1], &hyper_vendor_id[2]);
	94	if (!memcmp(hyper_vendor_id, "VMwareVMware", 12))
	95	return true;
fd8cd7e1	96	} else if (dmi_available && dmi_name_in_serial("VMware") &&
88b094fb	97	__vmware_platform())
e08cae41	98	return true;
88b094fb	99
e08cae41	100	return false;
88b094fb AK	101	}
88b094fb AK	102
eca0cd02 AK	103	/*
	104	* VMware hypervisor takes care of exporting a reliable TSC to the guest.
	105	* Still, due to timing difference when running on virtual cpus, the TSC can
	106	* be marked as unstable in some cases. For example, the TSC sync check at
	107	* bootup can fail due to a marginal offset between vcpus' TSCs (though the
	108	* TSCs do not drift from each other). Also, the ACPI PM timer clocksource
	109	* is not suitable as a watchdog when running on a hypervisor because the
	110	* kernel may miss a wrap of the counter if the vcpu is descheduled for a
	111	* long time. To skip these checks at runtime we set these capability bits,
	112	* so that the kernel could just trust the hypervisor with providing a
	113	* reliable virtual TSC that is suitable for timekeeping.
	114	*/
e08cae41	115	static void __cpuinit vmware_set_cpu_features(struct cpuinfo_x86 *c)
eca0cd02 AK	116	{
	117	set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
	118	set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
	119	}
e08cae41 PA	120
	121	const __refconst struct hypervisor_x86 x86_hyper_vmware = {
	122	.name = "VMware",
	123	.detect = vmware_platform,
	124	.set_cpu_features = vmware_set_cpu_features,
	125	.init_platform = vmware_platform_setup,
	126	};
96f6e775	127	EXPORT_SYMBOL(x86_hyper_vmware);