Hypervisor detection and get tsc_freq from hypervisor

PATCH In review Alok Kataria 4 participants 6 messages Oct 25, 2008 – Nov 10, 2008

Subsystems (2)

x86 VMware hypervisor interface

lore

Share & tools

lore

Alok Kataria

author

2008-10-25 00:22 UTC #0 lore raw

PATCH 2/4 Hypervisor detection and get tsc_freq from hypervisor

x86: Get TSC frequency from VMware hypervisor.

From: Alok N Kataria <[email protected]>

v3->v2 : Abstract the hypervisor detection and feature (tsc_freq) request
behind a hypervisor.c file
v2->v1 : Add a x86_hyper_vendor field to the cpuinfo_x86 structure.
This avoids multiple calls to the hypervisor detection function.

This patch adds functions to detect if we are running under VMware. The current way to check if we are on VMware is following, # check if "hypervisor present bit" is set, if so read the 0x40000000
cpuid leaf and check for "VMwareVMware" signature.
# if the above fails, check the DMI vendors name for "VMware" string
if we find one we query the VMware backdoor port to check if we are under VMware.

The DMI + Backdoor check is needed for older VMware products, which don't implement the hypervisor signature cpuid leaf.
Also note that since we are checking for the DMI signature the backdoor port would never be accessed on native hardware.

This patch also adds a hypervisor_get_tsc_freq function, instead of calibrating the frequency which can be error prone in virtualized environment, we ask the hypervisor for it. We get the frequency from the hypervisor by accessing the backdoor port if we are running on VMware. Other hypervisors too can add code to get frequency on their platform to this routine.

Signed-off-by Alok N Kataria <[email protected]>

Signed-off-by Dan Hecht <[email protected]>

Cc H. Peter Anvin <[email protected]>

---

 arch/x86/include/asm/cpufeature.h |    2 +
 arch/x86/include/asm/hypervisor.h |   26 +++++++++++
 arch/x86/include/asm/processor.h  |    4 ++
 arch/x86/include/asm/vmware.h     |   26 +++++++++++
 arch/x86/kernel/cpu/Makefile      |    1 
 arch/x86/kernel/cpu/common.c      |    2 +
 arch/x86/kernel/cpu/hypervisor.c  |   48 ++++++++++++++++++++
 arch/x86/kernel/cpu/vmware.c      |   87 +++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c           |    7 +++
 arch/x86/kernel/tsc.c             |    9 +++-
 10 files changed, 211 insertions(+), 1 deletions(-)
 create mode 100644 arch/x86/include/asm/hypervisor.h
 create mode 100644 arch/x86/include/asm/vmware.h
 create mode 100644 arch/x86/kernel/cpu/hypervisor.c
 create mode 100644 arch/x86/kernel/cpu/vmware.c

arch/x86/include/asm/cpufeature.h +2 -0

index f73e95d..78478f2 100644
@@ -117,6 +117,7 @@
 #define X86_FEATURE_XSAVE	(4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
 #define X86_FEATURE_OSXSAVE	(4*32+27) /* "" XSAVE enabled in the OS */
 #define X86_FEATURE_AVX		(4*32+28) /* Advanced Vector Extensions */
+#define X86_FEATURE_HYPERVISOR	(4*32+31) /* Running on a hypervisor */
 
 /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
 #define X86_FEATURE_XSTORE	(5*32+ 2) /* "rng" RNG present (xstore) */

@@ -237,6 +238,7 @@ extern const char * const x86_power_flags[32];
 #define cpu_has_xmm4_2		boot_cpu_has(X86_FEATURE_XMM4_2)
 #define cpu_has_x2apic		boot_cpu_has(X86_FEATURE_X2APIC)
 #define cpu_has_xsave		boot_cpu_has(X86_FEATURE_XSAVE)
+#define cpu_has_hypervisor	boot_cpu_has(X86_FEATURE_HYPERVISOR)
 
 #if defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_64)
 # define cpu_has_invlpg		1

arch/x86/include/asm/hypervisor.h new file +26 -0

new file mode 100644
index 0000000..369f5c5
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2008, VMware, Inc.
+ *
+ * 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.
+ *
+ */
+#ifndef ASM_X86__HYPERVISOR_H
+#define ASM_X86__HYPERVISOR_H
+
+extern unsigned long get_hypervisor_tsc_freq(void);
+extern void init_hypervisor(struct cpuinfo_x86 *c);
+
+#endif

arch/x86/include/asm/processor.h +4 -0

index 5ca01e3..a570eaf 100644
@@ -110,6 +110,7 @@ struct cpuinfo_x86 {
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 #endif
+	unsigned int		x86_hyper_vendor;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL	0

@@ -123,6 +124,9 @@ struct cpuinfo_x86 {
 
 #define X86_VENDOR_UNKNOWN	0xff
 
+#define X86_HYPER_VENDOR_NONE  0
+#define X86_HYPER_VENDOR_VMWARE 1
+
 /*
  * capabilities of CPUs
  */

arch/x86/include/asm/vmware.h new file +26 -0

new file mode 100644
index 0000000..02dfea5
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2008, VMware, Inc.
+ *
+ * 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.
+ *
+ */
+#ifndef ASM_X86__VMWARE_H
+#define ASM_X86__VMWARE_H
+
+extern unsigned long vmware_get_tsc_khz(void);
+extern int vmware_platform(void);
+
+#endif

arch/x86/kernel/cpu/Makefile +1 -0

index 82ec607..a5c04e8 100644
@@ -4,6 +4,7 @@
 
 obj-y			:= intel_cacheinfo.o addon_cpuid_features.o
 obj-y			+= proc.o capflags.o powerflags.o common.o
+obj-y			+= vmware.o hypervisor.o
 
 obj-$(CONFIG_X86_32)	+= bugs.o cmpxchg.o
 obj-$(CONFIG_X86_64)	+= bugs_64.o

arch/x86/kernel/cpu/common.c +2 -0

index 25581dc..c80d233 100644
@@ -35,6 +35,7 @@
 #include <asm/proto.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
+#include <asm/hypervisor.h>
 
 #include "cpu.h"

@@ -698,6 +699,7 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 	detect_ht(c);
 #endif
 
+	init_hypervisor(c);
 	/*
 	 * On SMP, boot_cpu_data holds the common feature set between
 	 * all CPUs; so make sure that we indicate which features are

arch/x86/kernel/cpu/hypervisor.c new file +48 -0

48 lines not on this page · raw message

arch/x86/kernel/cpu/vmware.c new file +87 -0

87 lines not on this page · raw message

arch/x86/kernel/setup.c +7 -0

index c35ec3f..47ba46f 100644
@@ -98,6 +98,7 @@
 
 #include <mach_apic.h>
 #include <asm/paravirt.h>
+#include <asm/hypervisor.h>
 
 #include <asm/percpu.h>
 #include <asm/topology.h>

@@ -911,6 +912,12 @@ void __init setup_arch(char **cmdline_p)
 
 	dmi_check_system(bad_bios_dmi_table);
 
+	/*
+	 * VMware detection requires dmi to be available, so this
+	 * needs to be done after dmi_scan_machine, for the BP.
+	 */
+	init_hypervisor(&boot_cpu_data);
+
 #ifdef CONFIG_X86_32
 	probe_roms();
 #endif

arch/x86/kernel/tsc.c +8 -1

index 161bb85..189741f 100644
@@ -15,6 +15,7 @@
 #include <asm/vgtod.h>
 #include <asm/time.h>
 #include <asm/delay.h>
+#include <asm/hypervisor.h>
 
 unsigned int cpu_khz;           /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);

@@ -352,9 +353,15 @@ unsigned long native_calibrate_tsc(void)
 {
 	u64 tsc1, tsc2, delta, ref1, ref2;
 	unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
-	unsigned long flags, latch, ms, fast_calibrate;
+	unsigned long flags, latch, ms, fast_calibrate, tsc_khz;
 	int hpet = is_hpet_enabled(), i, loopmin;
 
+	tsc_khz = get_hypervisor_tsc_freq();
+	if (tsc_khz) {
+		printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
+		return tsc_khz;
+	}
+
 	local_irq_save(flags);
 	fast_calibrate = quick_pit_calibrate();
 	local_irq_restore(flags);

Ingo Molnar

2008-10-27 11:01 UTC #1 lore raw

Quoted 1 line · Alok Kataria

The DMI + Backdoor [...]

please do _NOT_ call anything like this a "backdoor", anywhere in the source or the commit log. "Backdoor" is most commonly used for intentional security holes, and we dont want anything like that in the kernel code. What this code implements is not a backdoor, it is simply a facility to discover the hypervisor environment, not a "backdoor".

Ingo

Alok Kataria

author

2008-10-27 17:41 UTC #2 lore raw

Quoted 6 lines · Ingo Molnar

Quoted 1 line · Alok Kataria
The DMI + Backdoor [...]
please do _NOT_ call anything like this a "backdoor", anywhere in the source or the commit log.

Not a problem.

Below is the updated patch.

Thanks,
Alok

x86: Get TSC frequency from VMware hypervisor.

From: Alok N Kataria <[email protected]>

This patch adds function to detect if we are running under VMware. The current way to check if we are on VMware is following,
# check if "hypervisor present bit" is set, if so read the 0x40000000
cpuid leaf and check for "VMwareVMware" signature.
# if the above fails, check the DMI vendors name for "VMware" string
if we find one we query the VMware hypervisor port to check if we are under VMware.

The DMI + "VMware hypervisor port check" is needed for older VMware products, which don't implement the hypervisor signature cpuid leaf.
Also note that since we are checking for the DMI signature the hypervisor port should never be accessed on native hardware.

This patch also adds a hypervisor_get_tsc_freq function, instead of calibrating the frequency which can be error prone in virtualized environment, we ask the hypervisor for it. We get the frequency from the hypervisor by accessing the hypervisor port if we are running on VMware. Other hypervisors too can add code to the generic routine to get frequency on their platform.

Signed-off-by Alok N Kataria <[email protected]>

Signed-off-by Dan Hecht <[email protected]>

Cc H. Peter Anvin <[email protected]>

---

 arch/x86/include/asm/cpufeature.h |    2 +
 arch/x86/include/asm/hypervisor.h |   26 +++++++++++
 arch/x86/include/asm/processor.h  |    4 ++
 arch/x86/include/asm/vmware.h     |   26 +++++++++++
 arch/x86/kernel/cpu/Makefile      |    1 
 arch/x86/kernel/cpu/common.c      |    2 +
 arch/x86/kernel/cpu/hypervisor.c  |   48 ++++++++++++++++++++
 arch/x86/kernel/cpu/vmware.c      |   88 +++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c           |    7 +++
 arch/x86/kernel/tsc.c             |    9 +++-
 10 files changed, 212 insertions(+), 1 deletions(-)
 create mode 100644 arch/x86/include/asm/hypervisor.h
 create mode 100644 arch/x86/include/asm/vmware.h
 create mode 100644 arch/x86/kernel/cpu/hypervisor.c
 create mode 100644 arch/x86/kernel/cpu/vmware.c

arch/x86/include/asm/cpufeature.h +2 -0

index f73e95d..78478f2 100644
@@ -117,6 +117,7 @@
 #define X86_FEATURE_XSAVE	(4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
 #define X86_FEATURE_OSXSAVE	(4*32+27) /* "" XSAVE enabled in the OS */
 #define X86_FEATURE_AVX		(4*32+28) /* Advanced Vector Extensions */
+#define X86_FEATURE_HYPERVISOR	(4*32+31) /* Running on a hypervisor */
 
 /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
 #define X86_FEATURE_XSTORE	(5*32+ 2) /* "rng" RNG present (xstore) */

@@ -237,6 +238,7 @@ extern const char * const x86_power_flags[32];
 #define cpu_has_xmm4_2		boot_cpu_has(X86_FEATURE_XMM4_2)
 #define cpu_has_x2apic		boot_cpu_has(X86_FEATURE_X2APIC)
 #define cpu_has_xsave		boot_cpu_has(X86_FEATURE_XSAVE)
+#define cpu_has_hypervisor	boot_cpu_has(X86_FEATURE_HYPERVISOR)
 
 #if defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_64)
 # define cpu_has_invlpg		1

arch/x86/include/asm/hypervisor.h new file +26 -0

new file mode 100644
index 0000000..369f5c5
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2008, VMware, Inc.
+ *
+ * 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.
+ *
+ */
+#ifndef ASM_X86__HYPERVISOR_H
+#define ASM_X86__HYPERVISOR_H
+
+extern unsigned long get_hypervisor_tsc_freq(void);
+extern void init_hypervisor(struct cpuinfo_x86 *c);
+
+#endif

arch/x86/include/asm/processor.h +4 -0

index 5ca01e3..a570eaf 100644
@@ -110,6 +110,7 @@ struct cpuinfo_x86 {
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 #endif
+	unsigned int		x86_hyper_vendor;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL	0

@@ -123,6 +124,9 @@ struct cpuinfo_x86 {
 
 #define X86_VENDOR_UNKNOWN	0xff
 
+#define X86_HYPER_VENDOR_NONE  0
+#define X86_HYPER_VENDOR_VMWARE 1
+
 /*
  * capabilities of CPUs
  */

arch/x86/include/asm/vmware.h new file +26 -0

new file mode 100644
index 0000000..02dfea5
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2008, VMware, Inc.
+ *
+ * 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.
+ *
+ */
+#ifndef ASM_X86__VMWARE_H
+#define ASM_X86__VMWARE_H
+
+extern unsigned long vmware_get_tsc_khz(void);
+extern int vmware_platform(void);
+
+#endif

arch/x86/kernel/cpu/Makefile +1 -0

index 82ec607..a5c04e8 100644
@@ -4,6 +4,7 @@
 
 obj-y			:= intel_cacheinfo.o addon_cpuid_features.o
 obj-y			+= proc.o capflags.o powerflags.o common.o
+obj-y			+= vmware.o hypervisor.o
 
 obj-$(CONFIG_X86_32)	+= bugs.o cmpxchg.o
 obj-$(CONFIG_X86_64)	+= bugs_64.o

arch/x86/kernel/cpu/common.c +2 -0

index 25581dc..c80d233 100644
@@ -35,6 +35,7 @@
 #include <asm/proto.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
+#include <asm/hypervisor.h>
 
 #include "cpu.h"

@@ -698,6 +699,7 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 	detect_ht(c);
 #endif
 
+	init_hypervisor(c);
 	/*
 	 * On SMP, boot_cpu_data holds the common feature set between
 	 * all CPUs; so make sure that we indicate which features are

arch/x86/kernel/cpu/hypervisor.c new file +48 -0

48 lines not on this page · raw message

arch/x86/kernel/cpu/vmware.c new file +88 -0

88 lines not on this page · raw message

arch/x86/kernel/setup.c +7 -0

index c35ec3f..47ba46f 100644
@@ -98,6 +98,7 @@
 
 #include <mach_apic.h>
 #include <asm/paravirt.h>
+#include <asm/hypervisor.h>
 
 #include <asm/percpu.h>
 #include <asm/topology.h>

@@ -911,6 +912,12 @@ void __init setup_arch(char **cmdline_p)
 
 	dmi_check_system(bad_bios_dmi_table);
 
+	/*
+	 * VMware detection requires dmi to be available, so this
+	 * needs to be done after dmi_scan_machine, for the BP.
+	 */
+	init_hypervisor(&boot_cpu_data);
+
 #ifdef CONFIG_X86_32
 	probe_roms();
 #endif

arch/x86/kernel/tsc.c +8 -1

index 161bb85..189741f 100644
@@ -15,6 +15,7 @@
 #include <asm/vgtod.h>
 #include <asm/time.h>
 #include <asm/delay.h>
+#include <asm/hypervisor.h>
 
 unsigned int cpu_khz;           /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);

@@ -352,9 +353,15 @@ unsigned long native_calibrate_tsc(void)
 {
 	u64 tsc1, tsc2, delta, ref1, ref2;
 	unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
-	unsigned long flags, latch, ms, fast_calibrate;
+	unsigned long flags, latch, ms, fast_calibrate, tsc_khz;
 	int hpet = is_hpet_enabled(), i, loopmin;
 
+	tsc_khz = get_hypervisor_tsc_freq();
+	if (tsc_khz) {
+		printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
+		return tsc_khz;
+	}
+
 	local_irq_save(flags);
 	fast_calibrate = quick_pit_calibrate();
 	local_irq_restore(flags);

Alok Kataria

author

2008-11-03 19:31 UTC #3 lore raw

Hi,

The patch below fixes a problem with the implementation of vmware_get_tsc_khz.

Please pick this patch too.

Thanks,
Alok

x86-VMware: Fix vmware_get_tsc code

From: Alok N Kataria <[email protected]>

The current version of the code to get the tsc frequency from the VMware hypervisor, will be broken on processor with frequency (4G-1) HZ, because on such processors eax will have UINT_MAX and that would be legitimate.
We instead check that EBX did change to decide if we were able to read the frequency from the hypervisor.

Signed-off-by Alok N Kataria <[email protected]>

---

 arch/x86/kernel/cpu/vmware.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

arch/x86/kernel/cpu/vmware.c +2 -2

index 89bc346..b781e50 100644
@@ -36,7 +36,7 @@
 			"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) :	\
 			"0"(VMWARE_HYPERVISOR_MAGIC),			\
 			"1"(VMWARE_PORT_CMD_##cmd),			\
-			"2"(VMWARE_HYPERVISOR_PORT), "3"(0) :		\
+			"2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) :	\
 			"memory");
 
 static inline int __vmware_platform(void)

@@ -53,7 +53,7 @@ static unsigned long __vmware_get_tsc_khz(void)
 
         VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
 
-        if (eax == (uint32_t)-1)
+        if (ebx == UINT_MAX)
                 return 0;
         tsc_hz = eax | (((uint64_t)ebx) << 32);
         do_div(tsc_hz, 1000);

Mark McLoughlin

2008-11-10 12:40 UTC #4 lore raw

In reply to Alok Kataria

Hi Alok,

Quoted 56 lines · Alok Kataria

x86: Get TSC frequency from VMware hypervisor.
From: Alok N Kataria <[email protected]>
v3->v2 : Abstract the hypervisor detection and feature (tsc_freq) request
behind a hypervisor.c file
v2->v1 : Add a x86_hyper_vendor field to the cpuinfo_x86 structure.
This avoids multiple calls to the hypervisor detection function.
This patch adds function to detect if we are running under VMware. The current way to check if we are on VMware is following,
# check if "hypervisor present bit" is set, if so read the 0x40000000
cpuid leaf and check for "VMwareVMware" signature.
# if the above fails, check the DMI vendors name for "VMware" string
if we find one we query the VMware hypervisor port to check if we are under VMware.
The DMI + "VMware hypervisor port check" is needed for older VMware products, which don't implement the hypervisor signature cpuid leaf.
Also note that since we are checking for the DMI signature the hypervisor port should never be accessed on native hardware.
This patch also adds a hypervisor_get_tsc_freq function, instead of calibrating the frequency which can be error prone in virtualized environment, we ask the hypervisor for it. We get the frequency from the hypervisor by accessing the hypervisor port if we are running on VMware. Other hypervisors too can add code to the generic routine to get frequency on their platform.
Signed-off-by Alok N Kataria <[email protected]>
Signed-off-by Dan Hecht <[email protected]>
Cc H. Peter Anvin <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    2 +
 arch/x86/include/asm/hypervisor.h |   26 +++++++++++
 arch/x86/include/asm/processor.h  |    4 ++
 arch/x86/include/asm/vmware.h     |   26 +++++++++++
 arch/x86/kernel/cpu/Makefile      |    1 
 arch/x86/kernel/cpu/common.c      |    2 +
 arch/x86/kernel/cpu/hypervisor.c  |   48 ++++++++++++++++++++
 arch/x86/kernel/cpu/vmware.c      |   88 +++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c           |    7 +++
 arch/x86/kernel/tsc.c             |    9 +++-
 10 files changed, 212 insertions(+), 1 deletions(-)
 create mode 100644 arch/x86/include/asm/hypervisor.h
 create mode 100644 arch/x86/include/asm/vmware.h
 create mode 100644 arch/x86/kernel/cpu/hypervisor.c
 create mode 100644 arch/x86/kernel/cpu/vmware.c
arch/x86/include/asm/cpufeature.h +0 -0
index f73e95d..78478f2 100644

arch/x86/include/asm/cpufeature.h line 120

Quoted 4 lines

arch/x86/include/asm/cpufeature.h +1 -0

@@ -117,6 +117,7 @@
 #define X86_FEATURE_XSAVE	(4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
 #define X86_FEATURE_OSXSAVE	(4*32+27) /* "" XSAVE enabled in the OS */
 #define X86_FEATURE_AVX		(4*32+28) /* Advanced Vector Extensions */
+#define X86_FEATURE_HYPERVISOR	(4*32+31) /* Running on a hypervisor */

I don't see you set this anywhere.

Quoted 7 lines

arch/x86/include/asm/cpufeature.h +1 -0

 /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
 #define X86_FEATURE_XSTORE	(5*32+ 2) /* "rng" RNG present (xstore) */

@@ -237,6 +238,7 @@ extern const char * const x86_power_flags[32];
 #define cpu_has_xmm4_2		boot_cpu_has(X86_FEATURE_XMM4_2)
 #define cpu_has_x2apic		boot_cpu_has(X86_FEATURE_X2APIC)
 #define cpu_has_xsave		boot_cpu_has(X86_FEATURE_XSAVE)
+#define cpu_has_hypervisor	boot_cpu_has(X86_FEATURE_HYPERVISOR)

...

Quoted 6 lines

arch/x86/kernel/cpu/vmware.c new file +0 -0
new file mode 100644
index 0000000..d5d1b75
@@ -0,0 +1,88 @@

...

arch/x86/kernel/cpu/vmware.c line 76

Quoted 13 lines

arch/x86/kernel/cpu/vmware.c new file +13 -0

+int vmware_platform(void)
+{
+	if (cpu_has_hypervisor) {
+		unsigned int eax, ebx, ecx, edx;
+		char hyper_vendor_id[13];
+
+		cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &ebx, &ecx, &edx);
+		memcpy(hyper_vendor_id + 0, &ebx, 4);
+		memcpy(hyper_vendor_id + 4, &ecx, 4);
+		memcpy(hyper_vendor_id + 8, &edx, 4);
+		hyper_vendor_id[12] = '\0';
+		if (!strcmp(hyper_vendor_id, "VMwareVMware"))
+			return 1;

This seems to be the only use of cpu_has_hypervisor, but this is the hypervisor detection code, so it's not clear how you intended X86_FEATURE_HYPERVISOR be set before here?

Cheers,
Mark.

H. Peter Anvin

reviewer

2008-11-10 15:32 UTC #5 lore raw

Quoted 13 lines · Mark McLoughlin

arch/x86/include/asm/cpufeature.h line 120

Quoted 10 lines

arch/x86/include/asm/cpufeature.h +1 -0

index f73e95d..78478f2 100644
@@ -117,6 +117,7 @@
 #define X86_FEATURE_XSAVE	(4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
 #define X86_FEATURE_OSXSAVE	(4*32+27) /* "" XSAVE enabled in the OS */
 #define X86_FEATURE_AVX		(4*32+28) /* Advanced Vector Extensions */
+#define X86_FEATURE_HYPERVISOR	(4*32+31) /* Running on a hypervisor */

I don't see you set this anywhere.

This bit is set by the hypervisor in the pattern returned by the CPUID instruction.

-hpa