RFC - Cleaned up hypervisor layer

RFC - Cleaned up hypervisor layer

[H. Peter Anvin]

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This patch implements a cleaned up hypervisor layer, plus cleans up some
of the aspects of both Hank's MS-HyperV patch and the existing VMware
driver.  In particular, the MS-HyperV information is private
information, per system, not per CPU, and can thus simply be stored in
an ordinary global variable.  This also turns the hypervisor detection
into an information structure instead of just an identifier.

	-hpa

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diff --git a/arch/x86/include/asm/hyperv.h b/arch/x86/include/asm/hyperv.h
index 4604047..5df477a 100644
--- a/arch/x86/include/asm/hyperv.h
+++ b/arch/x86/include/asm/hyperv.h
@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_KVM_HYPERV_H
-#define _ASM_X86_KVM_HYPERV_H
+#ifndef _ASM_X86_HYPERV_H
+#define _ASM_X86_HYPERV_H
 
 #include <linux/types.h>
 
@@ -16,6 +16,7 @@
 
 #define HYPERV_HYPERVISOR_PRESENT_BIT		0x80000000
 #define HYPERV_CPUID_MIN			0x40000005
+#define HYPERV_CPUID_MAX			0x4000ffff
 
 /*
  * Feature identification. EAX indicates which features are available
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index b78c094..70abda7 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -17,10 +17,33 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  */
-#ifndef ASM_X86__HYPERVISOR_H
-#define ASM_X86__HYPERVISOR_H
+#ifndef _ASM_X86_HYPERVISOR_H
+#define _ASM_X86_HYPERVISOR_H
 
 extern void init_hypervisor(struct cpuinfo_x86 *c);
 extern void init_hypervisor_platform(void);
 
+/*
+ * x86 hypervisor information
+ */
+struct hypervisor_x86 {
+	/* Hypervisor name */
+	const char	*name;
+
+	/* Detection routine */
+	bool		(*detect)(void);
+
+	/* Adjust CPU feature bits (run once per CPU) */
+	void		(*set_cpu_features)(struct cpuinfo_x86 *);
+
+	/* Platform setup (run once per boot) */
+	void		(*init_platform)(void);
+};
+
+extern const struct hypervisor_x86 *x86_hyper;
+
+/* Recognized hypervisors */
+extern const struct hypervisor_x86 x86_hyper_vmware;
+extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
+
 #endif
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 6cd8101..79ce568 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -1,7 +1,14 @@
-#ifndef ASM_X86__MSHYPER_H
-#define ASM_X86__MSHYPER_H
+#ifndef _ASM_X86_MSHYPER_H
+#define _ASM_X86_MSHYPER_H
 
-int ms_hyperv_platform(void);
-void __cpuinit ms_hyperv_set_feature_bits(struct cpuinfo_x86 *c);
+#include <linux/types.h>
+#include <asm/hyperv.h>
+
+struct ms_hyperv_info {
+	u32 features;
+	u32 hints;
+};
+
+extern struct ms_hyperv_info ms_hyperv;
 
 #endif
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 597c041..e4f1dfb 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -113,9 +113,6 @@ struct cpuinfo_x86 {
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 #endif
-	unsigned int		x86_hyper_vendor;
-	/* The layout of this field is hypervisor specific */
-	unsigned int		x86_hyper_features;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL	0
@@ -129,10 +126,6 @@ struct cpuinfo_x86 {
 
 #define X86_VENDOR_UNKNOWN	0xff
 
-#define X86_HYPER_VENDOR_NONE  0
-#define X86_HYPER_VENDOR_VMWARE 1
-#define X86_HYPER_VENDOR_MSFT	2
-
 /*
  * capabilities of CPUs
  */
diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
deleted file mode 100644
index e49ed6d..0000000
--- a/arch/x86/include/asm/vmware.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * 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 void vmware_platform_setup(void);
-extern int vmware_platform(void);
-extern void vmware_set_feature_bits(struct cpuinfo_x86 *c);
-
-#endif
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index de3f4e0..888777a 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -22,40 +22,52 @@
  */
 
 #include <asm/processor.h>
-#include <asm/vmware.h>
-#include <asm/mshyperv.h>
 #include <asm/hypervisor.h>
 
-static inline void __cpuinit
-detect_hypervisor_vendor(struct cpuinfo_x86 *c)
+/*
+ * Hypervisor detect order.  This is specified explicitly here because
+ * some hypervisors might implement compatibility modes for other
+ * hypervisors and therefore need to be detected in specific sequence.
+ */
+static const __initconst struct hypervisor_x86 * const hypervisors[] =
 {
-	if (vmware_platform())
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_VMWARE;
-	else if (ms_hyperv_platform())
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_MSFT;
-	else
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_NONE;
-}
+	&x86_hyper_vmware,
+	&x86_hyper_ms_hyperv,
+};
+
+const struct hypervisor_x86 *x86_hyper;
 
-static inline void __cpuinit
-hypervisor_set_feature_bits(struct cpuinfo_x86 *c)
+static inline void __init
+detect_hypervisor_vendor(void)
 {
-	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
-		vmware_set_feature_bits(c);
-	else if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_MSFT)
-		ms_hyperv_set_feature_bits(c);
-	return;
+	const struct hypervisor_x86 *h, * const *p;
+
+	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
+		h = *p;
+		if (h->detect()) {
+			x86_hyper = h;
+			printk(KERN_INFO "Hypervisor detected: %s\n", h->name);
+			break;
+		}
+	}
 }
 
 void __cpuinit init_hypervisor(struct cpuinfo_x86 *c)
 {
-	detect_hypervisor_vendor(c);
-	hypervisor_set_feature_bits(c);
+	if (x86_hyper && x86_hyper->set_cpu_features)
+		x86_hyper->set_cpu_features(c);
 }
 
 void __init init_hypervisor_platform(void)
 {
+	
+	detect_hypervisor_vendor();
+
+	if (!x86_hyper)
+		return;
+
 	init_hypervisor(&boot_cpu_data);
-	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
-		vmware_platform_setup();
+
+	if (x86_hyper->init_platform)
+		x86_hyper->init_platform();
 }
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 2443b61..2a1a256 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -23,45 +23,42 @@
 
 #include <linux/types.h>
 #include <asm/processor.h>
+#include <asm/hypervisor.h>
 #include <asm/hyperv.h>
 #include <asm/mshyperv.h>
 
+struct ms_hyperv_info ms_hyperv;
 
-int ms_hyperv_platform(void)
+static bool __init ms_hyperv_platform(void)
 {
-	u32 eax, ebx, ecx, edx;
-	char hyp_signature[13];
+	u32 eax;
+	u32 hyp_signature[3];
 
-	cpuid(1, &eax, &ebx, &ecx, &edx);
-	if (!(ecx & HYPERV_HYPERVISOR_PRESENT_BIT))
-		return 0;
+	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
+		return false;
 
-	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &ebx, &ecx, &edx);
-	*(u32 *)(hyp_signature + 0) = ebx;
-	*(u32 *)(hyp_signature + 4) = ecx;
-	*(u32 *)(hyp_signature + 8) = edx;
+	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
+	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
 
-	if ((eax < HYPERV_CPUID_MIN) || (memcmp("Microsoft Hv", hyp_signature, 12)))
-		return 0;
-	return 1;
+	return eax >= HYPERV_CPUID_MIN && 
+		eax <= HYPERV_CPUID_MAX &&
+		!memcmp("Microsoft Hv", hyp_signature, 12);
 }
 
-void __cpuinit ms_hyperv_set_feature_bits(struct cpuinfo_x86 *c)
+static void __init ms_hyperv_init_platform(void)
 {
-	u32 eax, ebx, ecx, edx;
-
-	c->x86_hyper_features = 0;
 	/*
-	 * Extract the features, recommendations etc.
-	 * The first 9 bits will be used to track hypervisor features.
-	 * The next 6 bits will be used to track the hypervisor
-	 * recommendations.
+	 * Extract the features and hints
 	 */
-	cpuid(HYPERV_CPUID_FEATURES, &eax, &ebx, &ecx, &edx);
-	c->x86_hyper_features |= (eax & 0x1ff);
+	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
+	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
 
-	cpuid(HYPERV_CPUID_ENLIGHTMENT_INFO, &eax, &ebx, &ecx, &edx);
-	c->x86_hyper_features |= ((eax & 0x3f) << 9);
-	printk(KERN_INFO "Detected HyperV with features: %x\n",
-		c->x86_hyper_features);
+	printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
+	       ms_hyperv.features, ms_hyperv.hints);
 }
+
+const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
+	.name			= "Microsoft HyperV",
+	.detect			= ms_hyperv_platform,
+	.init_platform		= ms_hyperv_init_platform,
+};
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 1cbed97..46a5b5d 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -23,8 +23,8 @@
 
 #include <linux/dmi.h>
 #include <asm/div64.h>
-#include <asm/vmware.h>
 #include <asm/x86_init.h>
+#include <asm/hypervisor.h>
 
 #define CPUID_VMWARE_INFO_LEAF	0x40000000
 #define VMWARE_HYPERVISOR_MAGIC	0x564D5868
@@ -64,7 +64,7 @@ static unsigned long vmware_get_tsc_khz(void)
 	return tsc_hz;
 }
 
-void __init vmware_platform_setup(void)
+static void __init vmware_platform_setup(void)
 {
 	uint32_t eax, ebx, ecx, edx;
 
@@ -82,24 +82,21 @@ void __init vmware_platform_setup(void)
  * serial key should be enough, as this will always have a VMware
  * specific string when running under VMware hypervisor.
  */
-int vmware_platform(void)
+static bool __init 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;
+		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 1;
+		return true;
 
-	return 0;
+	return false;
 }
 
 /*
@@ -114,8 +111,15 @@ int vmware_platform(void)
  * so that the kernel could just trust the hypervisor with providing a
  * reliable virtual TSC that is suitable for timekeeping.
  */
-void __cpuinit vmware_set_feature_bits(struct cpuinfo_x86 *c)
+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,
+};

Re: RFC - Cleaned up hypervisor layer

[Greg KH]

On Fri, May 07, 2010 at 03:43:04PM -0700, H. Peter Anvin wrote:
> This patch implements a cleaned up hypervisor layer, plus cleans up some
> of the aspects of both Hank's MS-HyperV patch and the existing VMware
> driver.  In particular, the MS-HyperV information is private
> information, per system, not per CPU, and can thus simply be stored in
> an ordinary global variable.  This also turns the hypervisor detection
> into an information structure instead of just an identifier.

This looks great to me, thanks for doing this work.

As this is a diff on top of my previous patch, do you want me to merge
it in with it and resend it, or will you?

thanks,

greg k-h

Re: RFC - Cleaned up hypervisor layer

[H. Peter Anvin]

On 05/07/2010 04:02 PM, Greg KH wrote:
> On Fri, May 07, 2010 at 03:43:04PM -0700, H. Peter Anvin wrote:
>> This patch implements a cleaned up hypervisor layer, plus cleans up some
>> of the aspects of both Hank's MS-HyperV patch and the existing VMware
>> driver.  In particular, the MS-HyperV information is private
>> information, per system, not per CPU, and can thus simply be stored in
>> an ordinary global variable.  This also turns the hypervisor detection
>> into an information structure instead of just an identifier.
> 
> This looks great to me, thanks for doing this work.
> 
> As this is a diff on top of my previous patch, do you want me to merge
> it in with it and resend it, or will you?
> 

I was planning to put this on top of your patch as a second commit, just
to preserve history and authorship.

	-ha

Re: RFC - Cleaned up hypervisor layer

[Greg KH]

On Fri, May 07, 2010 at 04:08:38PM -0700, H. Peter Anvin wrote:
> On 05/07/2010 04:02 PM, Greg KH wrote:
> > On Fri, May 07, 2010 at 03:43:04PM -0700, H. Peter Anvin wrote:
> >> This patch implements a cleaned up hypervisor layer, plus cleans up some
> >> of the aspects of both Hank's MS-HyperV patch and the existing VMware
> >> driver.  In particular, the MS-HyperV information is private
> >> information, per system, not per CPU, and can thus simply be stored in
> >> an ordinary global variable.  This also turns the hypervisor detection
> >> into an information structure instead of just an identifier.
> > 
> > This looks great to me, thanks for doing this work.
> > 
> > As this is a diff on top of my previous patch, do you want me to merge
> > it in with it and resend it, or will you?
> > 
> 
> I was planning to put this on top of your patch as a second commit, just
> to preserve history and authorship.

Wonderful.

Ah, I just realized that we cut-and-pasted the GPL lines from the vmware
file, I don't want the "v2 or later" marking on the new file KY added.
Want me to send an add-on patch to fix that up?

thanks,

greg k-h

Re: RFC - Cleaned up hypervisor layer

[H. Peter Anvin]

On 05/07/2010 04:12 PM, Greg KH wrote:
> On Fri, May 07, 2010 at 04:08:38PM -0700, H. Peter Anvin wrote:
>> On 05/07/2010 04:02 PM, Greg KH wrote:
>>> On Fri, May 07, 2010 at 03:43:04PM -0700, H. Peter Anvin wrote:
>>>> This patch implements a cleaned up hypervisor layer, plus cleans up some
>>>> of the aspects of both Hank's MS-HyperV patch and the existing VMware
>>>> driver.  In particular, the MS-HyperV information is private
>>>> information, per system, not per CPU, and can thus simply be stored in
>>>> an ordinary global variable.  This also turns the hypervisor detection
>>>> into an information structure instead of just an identifier.
>>>
>>> This looks great to me, thanks for doing this work.
>>>
>>> As this is a diff on top of my previous patch, do you want me to merge
>>> it in with it and resend it, or will you?
>>>
>>
>> I was planning to put this on top of your patch as a second commit, just
>> to preserve history and authorship.
> 
> Wonderful.
> 
> Ah, I just realized that we cut-and-pasted the GPL lines from the vmware
> file, I don't want the "v2 or later" marking on the new file KY added.
> Want me to send an add-on patch to fix that up?
> 

Yes please.

	-hpa

[PATCH] HyperV: fix up the license to mshyperv.c

[Greg KH]

From: Greg Kroah-Hartman <gregkh@suse.de>

This should have been GPLv2 only, we cut and pasted from the wrong file
originally, sorry.

Also removed some unneeded boilerplate license code, we all know where
to find the GPLv2, and that there's no warranty as that is implicit from
the license.

Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 arch/x86/kernel/cpu/mshyperv.c |   13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -6,18 +6,7 @@
  *
  * 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.
+ * the Free Software Foundation; version 2 of the License.
  *
  */
 

[tip:x86/cpu] x86, HyperV: fix up the license to mshyperv.c

[tip-bot for Greg Kroah-Hartman]

Commit-ID:  9fa02317429449e8176c9bb6da3ac00eb14d52d3
Gitweb:     http://git.kernel.org/tip/9fa02317429449e8176c9bb6da3ac00eb14d52d3
Author:     Greg Kroah-Hartman <gregkh@suse.de>
AuthorDate: Fri, 7 May 2010 16:55:41 -0700
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Fri, 7 May 2010 17:00:25 -0700

x86, HyperV: fix up the license to mshyperv.c

This should have been GPLv2 only, we cut and pasted from the wrong file
originally, sorry.

Also removed some unneeded boilerplate license code, we all know where
to find the GPLv2, and that there's no warranty as that is implicit from
the license.

Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
LKML-Reference: <20100507235541.GA15448@kroah.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/cpu/mshyperv.c |   13 +------------
 1 files changed, 1 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 2443b61..a58d8e6 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -6,18 +6,7 @@
  *
  * 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.
+ * the Free Software Foundation; version 2 of the License.
  *
  */
 

[tip:x86/cpu] x86: Clean up the hypervisor layer

[tip-bot for H. Peter Anvin]

Commit-ID:  e08cae4181af9483b04ecfac48f01c8e5a5f27bf
Gitweb:     http://git.kernel.org/tip/e08cae4181af9483b04ecfac48f01c8e5a5f27bf
Author:     H. Peter Anvin <hpa@zytor.com>
AuthorDate: Fri, 7 May 2010 16:57:28 -0700
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Fri, 7 May 2010 17:13:04 -0700

x86: Clean up the hypervisor layer

Clean up the hypervisor layer and the hypervisor drivers, using an ops
structure instead of an enumeration with if statements.

The identity of the hypervisor, if needed, can be tested by testing
the pointer value in x86_hyper.

The MS-HyperV private state is moved into a normal global variable
(it's per-system state, not per-CPU state).  Being a normal bss
variable, it will be left at all zero on non-HyperV platforms, and so
can generally be tested for HyperV-specific features without
additional qualification.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
---
 arch/x86/include/asm/hyperv.h     |    5 ++-
 arch/x86/include/asm/hypervisor.h |   27 ++++++++++++++++-
 arch/x86/include/asm/mshyperv.h   |   15 +++++++--
 arch/x86/include/asm/processor.h  |    7 ----
 arch/x86/include/asm/vmware.h     |   27 ------------------
 arch/x86/kernel/cpu/hypervisor.c  |   56 ++++++++++++++++++++++--------------
 arch/x86/kernel/cpu/mshyperv.c    |   51 ++++++++++++++++------------------
 arch/x86/kernel/cpu/vmware.c      |   36 +++++++++++++----------
 8 files changed, 117 insertions(+), 107 deletions(-)

diff --git a/arch/x86/include/asm/hyperv.h b/arch/x86/include/asm/hyperv.h
index 4604047..5df477a 100644
--- a/arch/x86/include/asm/hyperv.h
+++ b/arch/x86/include/asm/hyperv.h
@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_KVM_HYPERV_H
-#define _ASM_X86_KVM_HYPERV_H
+#ifndef _ASM_X86_HYPERV_H
+#define _ASM_X86_HYPERV_H
 
 #include <linux/types.h>
 
@@ -16,6 +16,7 @@
 
 #define HYPERV_HYPERVISOR_PRESENT_BIT		0x80000000
 #define HYPERV_CPUID_MIN			0x40000005
+#define HYPERV_CPUID_MAX			0x4000ffff
 
 /*
  * Feature identification. EAX indicates which features are available
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index b78c094..70abda7 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -17,10 +17,33 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  */
-#ifndef ASM_X86__HYPERVISOR_H
-#define ASM_X86__HYPERVISOR_H
+#ifndef _ASM_X86_HYPERVISOR_H
+#define _ASM_X86_HYPERVISOR_H
 
 extern void init_hypervisor(struct cpuinfo_x86 *c);
 extern void init_hypervisor_platform(void);
 
+/*
+ * x86 hypervisor information
+ */
+struct hypervisor_x86 {
+	/* Hypervisor name */
+	const char	*name;
+
+	/* Detection routine */
+	bool		(*detect)(void);
+
+	/* Adjust CPU feature bits (run once per CPU) */
+	void		(*set_cpu_features)(struct cpuinfo_x86 *);
+
+	/* Platform setup (run once per boot) */
+	void		(*init_platform)(void);
+};
+
+extern const struct hypervisor_x86 *x86_hyper;
+
+/* Recognized hypervisors */
+extern const struct hypervisor_x86 x86_hyper_vmware;
+extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
+
 #endif
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 6cd8101..79ce568 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -1,7 +1,14 @@
-#ifndef ASM_X86__MSHYPER_H
-#define ASM_X86__MSHYPER_H
+#ifndef _ASM_X86_MSHYPER_H
+#define _ASM_X86_MSHYPER_H
 
-int ms_hyperv_platform(void);
-void __cpuinit ms_hyperv_set_feature_bits(struct cpuinfo_x86 *c);
+#include <linux/types.h>
+#include <asm/hyperv.h>
+
+struct ms_hyperv_info {
+	u32 features;
+	u32 hints;
+};
+
+extern struct ms_hyperv_info ms_hyperv;
 
 #endif
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 597c041..e4f1dfb 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -113,9 +113,6 @@ struct cpuinfo_x86 {
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 #endif
-	unsigned int		x86_hyper_vendor;
-	/* The layout of this field is hypervisor specific */
-	unsigned int		x86_hyper_features;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL	0
@@ -129,10 +126,6 @@ struct cpuinfo_x86 {
 
 #define X86_VENDOR_UNKNOWN	0xff
 
-#define X86_HYPER_VENDOR_NONE  0
-#define X86_HYPER_VENDOR_VMWARE 1
-#define X86_HYPER_VENDOR_MSFT	2
-
 /*
  * capabilities of CPUs
  */
diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
deleted file mode 100644
index e49ed6d..0000000
--- a/arch/x86/include/asm/vmware.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * 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 void vmware_platform_setup(void);
-extern int vmware_platform(void);
-extern void vmware_set_feature_bits(struct cpuinfo_x86 *c);
-
-#endif
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index de3f4e0..8738175 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -22,40 +22,52 @@
  */
 
 #include <asm/processor.h>
-#include <asm/vmware.h>
-#include <asm/mshyperv.h>
 #include <asm/hypervisor.h>
 
-static inline void __cpuinit
-detect_hypervisor_vendor(struct cpuinfo_x86 *c)
+/*
+ * Hypervisor detect order.  This is specified explicitly here because
+ * some hypervisors might implement compatibility modes for other
+ * hypervisors and therefore need to be detected in specific sequence.
+ */
+static const __initconst struct hypervisor_x86 * const hypervisors[] =
 {
-	if (vmware_platform())
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_VMWARE;
-	else if (ms_hyperv_platform())
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_MSFT;
-	else
-		c->x86_hyper_vendor = X86_HYPER_VENDOR_NONE;
-}
+	&x86_hyper_vmware,
+	&x86_hyper_ms_hyperv,
+};
 
-static inline void __cpuinit
-hypervisor_set_feature_bits(struct cpuinfo_x86 *c)
+const struct hypervisor_x86 *x86_hyper;
+
+static inline void __init
+detect_hypervisor_vendor(void)
 {
-	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
-		vmware_set_feature_bits(c);
-	else if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_MSFT)
-		ms_hyperv_set_feature_bits(c);
-	return;
+	const struct hypervisor_x86 *h, * const *p;
+
+	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
+		h = *p;
+		if (h->detect()) {
+			x86_hyper = h;
+			printk(KERN_INFO "Hypervisor detected: %s\n", h->name);
+			break;
+		}
+	}
 }
 
 void __cpuinit init_hypervisor(struct cpuinfo_x86 *c)
 {
-	detect_hypervisor_vendor(c);
-	hypervisor_set_feature_bits(c);
+	if (x86_hyper && x86_hyper->set_cpu_features)
+		x86_hyper->set_cpu_features(c);
 }
 
 void __init init_hypervisor_platform(void)
 {
+
+	detect_hypervisor_vendor();
+
+	if (!x86_hyper)
+		return;
+
 	init_hypervisor(&boot_cpu_data);
-	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
-		vmware_platform_setup();
+
+	if (x86_hyper->init_platform)
+		x86_hyper->init_platform();
 }
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index a58d8e6..5969c3e 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -12,45 +12,42 @@
 
 #include <linux/types.h>
 #include <asm/processor.h>
+#include <asm/hypervisor.h>
 #include <asm/hyperv.h>
 #include <asm/mshyperv.h>
 
+struct ms_hyperv_info ms_hyperv;
 
-int ms_hyperv_platform(void)
+static bool __init ms_hyperv_platform(void)
 {
-	u32 eax, ebx, ecx, edx;
-	char hyp_signature[13];
+	u32 eax;
+	u32 hyp_signature[3];
 
-	cpuid(1, &eax, &ebx, &ecx, &edx);
-	if (!(ecx & HYPERV_HYPERVISOR_PRESENT_BIT))
-		return 0;
+	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
+		return false;
 
-	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &ebx, &ecx, &edx);
-	*(u32 *)(hyp_signature + 0) = ebx;
-	*(u32 *)(hyp_signature + 4) = ecx;
-	*(u32 *)(hyp_signature + 8) = edx;
+	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
+	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
 
-	if ((eax < HYPERV_CPUID_MIN) || (memcmp("Microsoft Hv", hyp_signature, 12)))
-		return 0;
-	return 1;
+	return eax >= HYPERV_CPUID_MIN &&
+		eax <= HYPERV_CPUID_MAX &&
+		!memcmp("Microsoft Hv", hyp_signature, 12);
 }
 
-void __cpuinit ms_hyperv_set_feature_bits(struct cpuinfo_x86 *c)
+static void __init ms_hyperv_init_platform(void)
 {
-	u32 eax, ebx, ecx, edx;
-
-	c->x86_hyper_features = 0;
 	/*
-	 * Extract the features, recommendations etc.
-	 * The first 9 bits will be used to track hypervisor features.
-	 * The next 6 bits will be used to track the hypervisor
-	 * recommendations.
+	 * Extract the features and hints
 	 */
-	cpuid(HYPERV_CPUID_FEATURES, &eax, &ebx, &ecx, &edx);
-	c->x86_hyper_features |= (eax & 0x1ff);
+	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
+	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
 
-	cpuid(HYPERV_CPUID_ENLIGHTMENT_INFO, &eax, &ebx, &ecx, &edx);
-	c->x86_hyper_features |= ((eax & 0x3f) << 9);
-	printk(KERN_INFO "Detected HyperV with features: %x\n",
-		c->x86_hyper_features);
+	printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
+	       ms_hyperv.features, ms_hyperv.hints);
 }
+
+const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
+	.name			= "Microsoft HyperV",
+	.detect			= ms_hyperv_platform,
+	.init_platform		= ms_hyperv_init_platform,
+};
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 1cbed97..46a5b5d 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -23,8 +23,8 @@
 
 #include <linux/dmi.h>
 #include <asm/div64.h>
-#include <asm/vmware.h>
 #include <asm/x86_init.h>
+#include <asm/hypervisor.h>
 
 #define CPUID_VMWARE_INFO_LEAF	0x40000000
 #define VMWARE_HYPERVISOR_MAGIC	0x564D5868
@@ -64,7 +64,7 @@ static unsigned long vmware_get_tsc_khz(void)
 	return tsc_hz;
 }
 
-void __init vmware_platform_setup(void)
+static void __init vmware_platform_setup(void)
 {
 	uint32_t eax, ebx, ecx, edx;
 
@@ -82,24 +82,21 @@ void __init vmware_platform_setup(void)
  * serial key should be enough, as this will always have a VMware
  * specific string when running under VMware hypervisor.
  */
-int vmware_platform(void)
+static bool __init 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;
+		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 1;
+		return true;
 
-	return 0;
+	return false;
 }
 
 /*
@@ -114,8 +111,15 @@ int vmware_platform(void)
  * so that the kernel could just trust the hypervisor with providing a
  * reliable virtual TSC that is suitable for timekeeping.
  */
-void __cpuinit vmware_set_feature_bits(struct cpuinfo_x86 *c)
+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,
+};

Re: RFC - Cleaned up hypervisor layer

[Dmitry Torokhov]

On Friday 07 May 2010 03:43:04 pm H. Peter Anvin wrote:
> @@ -82,24 +82,21 @@ void __init vmware_platform_setup(void)
> 
>   * serial key should be enough, as this will always have a VMware
>   * specific string when running under VMware hypervisor.
>   */
> 
> -int vmware_platform(void)
> +static bool __init vmware_platform(void)

This will break our balloon driver which uses vmware_platform() to detect
whether it should run or not.

Thanks.

-- 
Dmitry

Re: [tip:x86/cpu] x86: Clean up the hypervisor layer

[Ingo Molnar]

* tip-bot for H. Peter Anvin <hpa@zytor.com> wrote:

> Commit-ID:  e08cae4181af9483b04ecfac48f01c8e5a5f27bf
> Gitweb:     http://git.kernel.org/tip/e08cae4181af9483b04ecfac48f01c8e5a5f27bf
> Author:     H. Peter Anvin <hpa@zytor.com>
> AuthorDate: Fri, 7 May 2010 16:57:28 -0700
> Committer:  H. Peter Anvin <hpa@zytor.com>
> CommitDate: Fri, 7 May 2010 17:13:04 -0700
> 
> x86: Clean up the hypervisor layer
> 
> Clean up the hypervisor layer and the hypervisor drivers, using an ops
> structure instead of an enumeration with if statements.
> 
> The identity of the hypervisor, if needed, can be tested by testing
> the pointer value in x86_hyper.
> 
> The MS-HyperV private state is moved into a normal global variable
> (it's per-system state, not per-CPU state).  Being a normal bss
> variable, it will be left at all zero on non-HyperV platforms, and so
> can generally be tested for HyperV-specific features without
> additional qualification.
> 
> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
> Acked-by: Greg KH <greg@kroah.com>
> Cc: Hank Janssen <hjanssen@microsoft.com>
> Cc: Alok Kataria <akataria@vmware.com>
> Cc: Ky Srinivasan <ksrinivasan@novell.com>
> LKML-Reference: <4BE49778.6060800@zytor.com>
> ---
>  arch/x86/include/asm/hyperv.h     |    5 ++-
>  arch/x86/include/asm/hypervisor.h |   27 ++++++++++++++++-
>  arch/x86/include/asm/mshyperv.h   |   15 +++++++--
>  arch/x86/include/asm/processor.h  |    7 ----
>  arch/x86/include/asm/vmware.h     |   27 ------------------
>  arch/x86/kernel/cpu/hypervisor.c  |   56 ++++++++++++++++++++++--------------
>  arch/x86/kernel/cpu/mshyperv.c    |   51 ++++++++++++++++------------------
>  arch/x86/kernel/cpu/vmware.c      |   36 +++++++++++++----------
>  8 files changed, 117 insertions(+), 107 deletions(-)

Note, this patch breaks the build of the new vmware baloon driver:

  drivers/misc/vmware_balloon.c:44:24: error: asm/vmware.h: No such file or directory

CONFIG_VMWARE_BALLOON=y

Thanks,

	Ingo

[tip:x86/cpu] x86, hypervisor: Export the x86_hyper* symbols

[tip-bot for H. Peter Anvin]

Commit-ID:  96f6e775b58687d85ee33004d414419b5ec34106
Gitweb:     http://git.kernel.org/tip/96f6e775b58687d85ee33004d414419b5ec34106
Author:     H. Peter Anvin <hpa@zytor.com>
AuthorDate: Sun, 9 May 2010 01:10:34 -0700
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Sun, 9 May 2010 01:10:34 -0700

x86, hypervisor: Export the x86_hyper* symbols

Export x86_hyper and the related specific structures, allowing for
hypervisor identification by modules.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
---
 arch/x86/kernel/cpu/hypervisor.c |    1 +
 arch/x86/kernel/cpu/mshyperv.c   |    1 +
 arch/x86/kernel/cpu/vmware.c     |    2 +-
 3 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 8738175..4afb5a2 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -36,6 +36,7 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
 };
 
 const struct hypervisor_x86 *x86_hyper;
+EXPORT_SYMBOL(x86_hyper);
 
 static inline void __init
 detect_hypervisor_vendor(void)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 5969c3e..0f13717 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -51,3 +51,4 @@ const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
 	.detect			= ms_hyperv_platform,
 	.init_platform		= ms_hyperv_init_platform,
 };
+EXPORT_SYMBOL(x86_hyper_ms_hyperv);
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 265b432..b9d1ff5 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -99,7 +99,6 @@ static bool __init vmware_platform(void)
 
 	return false;
 }
-EXPORT_SYMBOL(vmware_platform);
 
 /*
  * VMware hypervisor takes care of exporting a reliable TSC to the guest.
@@ -125,3 +124,4 @@ const __refconst struct hypervisor_x86 x86_hyper_vmware = {
 	.set_cpu_features	= vmware_set_cpu_features,
 	.init_platform		= vmware_platform_setup,
 };
+EXPORT_SYMBOL(x86_hyper_vmware);

[tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[tip-bot for H. Peter Anvin]

Commit-ID:  a10a569806e43b9be5fce60b21f836b50b1010e4
Gitweb:     http://git.kernel.org/tip/a10a569806e43b9be5fce60b21f836b50b1010e4
Author:     H. Peter Anvin <hpa@zytor.com>
AuthorDate: Sun, 9 May 2010 01:13:42 -0700
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Sun, 9 May 2010 01:13:42 -0700

Modify the VMware balloon driver for the new x86_hyper API

Modify the VMware balloon driver to match the new x86_hyper API.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
---
 drivers/misc/vmware_balloon.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/vmware_balloon.c b/drivers/misc/vmware_balloon.c
index e7161c4..db9cd02 100644
--- a/drivers/misc/vmware_balloon.c
+++ b/drivers/misc/vmware_balloon.c
@@ -41,7 +41,7 @@
 #include <linux/workqueue.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
-#include <asm/vmware.h>
+#include <asm/hypervisor.h>
 
 MODULE_AUTHOR("VMware, Inc.");
 MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
@@ -767,7 +767,7 @@ static int __init vmballoon_init(void)
 	 * Check if we are running on VMware's hypervisor and bail out
 	 * if we are not.
 	 */
-	if (!vmware_platform())
+	if (x86_hyper != &x86_hyper_vmware)
 		return -ENODEV;
 
 	vmballoon_wq = create_freezeable_workqueue("vmmemctl");

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[H. Peter Anvin]

On 05/09/2010 01:19 AM, tip-bot for H. Peter Anvin wrote:
>  
>  MODULE_AUTHOR("VMware, Inc.");
>  MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
> @@ -767,7 +767,7 @@ static int __init vmballoon_init(void)
>  	 * Check if we are running on VMware's hypervisor and bail out
>  	 * if we are not.
>  	 */
> -	if (!vmware_platform())
> +	if (x86_hyper != &x86_hyper_vmware)
>  		return -ENODEV;
>  
>  	vmballoon_wq = create_freezeable_workqueue("vmmemctl");

Note: I did not change the existing code, but this is an example of a
very common bug: the appropriate error code for "hardware is not
present" is ENXIO, not ENODEV.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[Ingo Molnar]

* tip-bot for H. Peter Anvin <hpa@zytor.com> wrote:

> Commit-ID:  a10a569806e43b9be5fce60b21f836b50b1010e4
> Gitweb:     http://git.kernel.org/tip/a10a569806e43b9be5fce60b21f836b50b1010e4
> Author:     H. Peter Anvin <hpa@zytor.com>
> AuthorDate: Sun, 9 May 2010 01:13:42 -0700
> Committer:  H. Peter Anvin <hpa@zytor.com>
> CommitDate: Sun, 9 May 2010 01:13:42 -0700
> 
> Modify the VMware balloon driver for the new x86_hyper API
> 
> Modify the VMware balloon driver to match the new x86_hyper API.

FYI, this is still not enough - now the allmodconfig build fails with:

ERROR: "x86_hyper" [drivers/misc/vmware_balloon.ko] undefined!

	Ingo

[tip:x86/cpu] x86, hypervisor: add missing <linux/module.h>

[tip-bot for H. Peter Anvin]

Commit-ID:  3998d095354d2a3062bdaa821ef07a1e1c82873c
Gitweb:     http://git.kernel.org/tip/3998d095354d2a3062bdaa821ef07a1e1c82873c
Author:     H. Peter Anvin <hpa@zytor.com>
AuthorDate: Sun, 9 May 2010 22:46:54 -0700
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Sun, 9 May 2010 22:46:54 -0700

x86, hypervisor: add missing <linux/module.h>

EXPORT_SYMBOL() needs <linux/module.h> to be included; fixes modular
builds of the VMware balloon driver, and any future modular drivers
which depends on the hypervisor.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
---
 arch/x86/kernel/cpu/hypervisor.c |    1 +
 arch/x86/kernel/cpu/mshyperv.c   |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 4afb5a2..dd531cc 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -21,6 +21,7 @@
  *
  */
 
+#include <linux/module.h>
 #include <asm/processor.h>
 #include <asm/hypervisor.h>
 
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 0f13717..16f41bb 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/types.h>
+#include <linux/module.h>
 #include <asm/processor.h>
 #include <asm/hypervisor.h>
 #include <asm/hyperv.h>

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[Dmitry Torokhov]

On Sunday 09 May 2010 01:20:44 am H. Peter Anvin wrote:
> On 05/09/2010 01:19 AM, tip-bot for H. Peter Anvin wrote:
> >  MODULE_AUTHOR("VMware, Inc.");
> >  MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
> > 
> > @@ -767,7 +767,7 @@ static int __init vmballoon_init(void)
> > 
> >  	 * Check if we are running on VMware's hypervisor and bail out
> >  	 * if we are not.
> >  	 */
> > 
> > -	if (!vmware_platform())
> > +	if (x86_hyper != &x86_hyper_vmware)
> > 
> >  		return -ENODEV;
> >  	
> >  	vmballoon_wq = create_freezeable_workqueue("vmmemctl");
> 
> Note: I did not change the existing code, but this is an example of a
> very common bug: the appropriate error code for "hardware is not
> present" is ENXIO, not ENODEV.
>

Source please? I was not aware that there was a standard governing
returns code for module init methods.

-- 
Dmitry

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[H. Peter Anvin]

On 05/10/2010 01:06 AM, Dmitry Torokhov wrote:
> 
> Source please? I was not aware that there was a standard governing
> returns code for module init methods.
> 

ENODEV means "not a device node."
ENXIO means "hardware not present."

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[Dmitry Torokhov]

On Monday 10 May 2010 08:23:28 am H. Peter Anvin wrote:
> On 05/10/2010 01:06 AM, Dmitry Torokhov wrote:
> > Source please? I was not aware that there was a standard governing
> > returns code for module init methods.
> 
> ENODEV means "not a device node."
> ENXIO means "hardware not present."
>

There is no device node in question. Again, could you please point me to
the list of allowed error codes for init methods? According to SUS,
we need to follow ERROR section of the appropriate function, and I do
not believe that spec covers cases if driver binding and module loading. 

FWIW -ENODEV is explicitly allowed in our device core and means "device
not found", especially in context of platform devices. I do not see the
need of changing that.

Thanks.

-- 
Dmitry

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[H. Peter Anvin]

On 05/10/2010 09:17 AM, Dmitry Torokhov wrote:
> On Monday 10 May 2010 08:23:28 am H. Peter Anvin wrote:
>> On 05/10/2010 01:06 AM, Dmitry Torokhov wrote:
>>> Source please? I was not aware that there was a standard governing
>>> returns code for module init methods.
>>
>> ENODEV means "not a device node."
>> ENXIO means "hardware not present."
>>
> 
> There is no device node in question. Again, could you please point me to
> the list of allowed error codes for init methods? According to SUS,
> we need to follow ERROR section of the appropriate function, and I do
> not believe that spec covers cases if driver binding and module loading. 
> 
> FWIW -ENODEV is explicitly allowed in our device core and means "device
> not found", especially in context of platform devices. I do not see the
> need of changing that.
> 

The problem with this abuse of ENODEV is that people start using it
elsewhere, where it *DOES* matter than ENXIO is the proper return code.
 Yes, we handle incorrect uses of ENODEV, but the right thing to do is
to teach people to use ENXIO properly.

	-hpa

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[Dmitry Torokhov]

On Monday 10 May 2010 10:30:43 am H. Peter Anvin wrote:
> On 05/10/2010 09:17 AM, Dmitry Torokhov wrote:
> > On Monday 10 May 2010 08:23:28 am H. Peter Anvin wrote:
> >> On 05/10/2010 01:06 AM, Dmitry Torokhov wrote:
> >>> Source please? I was not aware that there was a standard governing
> >>> returns code for module init methods.
> >> 
> >> ENODEV means "not a device node."
> >> ENXIO means "hardware not present."
> > 
> > There is no device node in question. Again, could you please point me to
> > the list of allowed error codes for init methods? According to SUS,
> > we need to follow ERROR section of the appropriate function, and I do
> > not believe that spec covers cases if driver binding and module loading.
> > 
> > FWIW -ENODEV is explicitly allowed in our device core and means "device
> > not found", especially in context of platform devices. I do not see the
> > need of changing that.
> 
> The problem with this abuse of ENODEV is that people start using it
> elsewhere, where it *DOES* matter than ENXIO is the proper return code.
>  Yes, we handle incorrect uses of ENODEV, but the right thing to do is
> to teach people to use ENXIO properly.

The usage that you mention only valid in the context of working with
device nodes. In other cases it can be used to indicate different errors
altogether:

mmap:

[ENODEV]
    The fildes argument refers to a file whose type is not supported
    by mmap().

fallocate:

[ENODEV]
    The fd argument does not refer to a regular file.

Linux mount:

      ENODEV filesystemtype not configured in the kernel.

      ENXIO  The major number of the block device source is out of range.

Solaris ldi:

ENODEV

    Requested device does not exist.

ENXIO

    Unsupported device operation or access mode.

and so on...

-- 
Dmitry

Re: [tip:x86/cpu] Modify the VMware balloon driver for the new x86_hyper API

[H. Peter Anvin]

On 05/10/2010 10:52 AM, Dmitry Torokhov wrote:
> 
> The usage that you mention only valid in the context of working with
> device nodes. In other cases it can be used to indicate different errors
> altogether:
> 
> mmap:
> 
> [ENODEV]
>     The fildes argument refers to a file whose type is not supported
>     by mmap().
> 
> fallocate:
> 
> [ENODEV]
>     The fd argument does not refer to a regular file.
> 
> Linux mount:
> 
>       ENODEV filesystemtype not configured in the kernel.
> 
>       ENXIO  The major number of the block device source is out of range.
> 

"The major number of the block device source is out of range" is really
nothing but confusion on the part of the man page author.  It's exactly
this kind of confusion which I try to clamp down on, because we have
*so* many instances of it in the existing codebase.  It seems, in fact,
to be one of the most common mistakes

ENXIO really means exactly the same thing as it does elsewhere: no
hardware for the specified device.  For example, create /dev/hda on a
system with no IDE:

mount("/dev/hda", "/mnt", "ext2", MS_MGC_VAL, NULL) = -1 ENXIO (No such
device or address)

[no "out of range" anything there...]

The kernel does indeed return ENODEV for a nonexistent filesystem name,
which can only best be described as "severely confusing", but probably
have to be considered grandfathered in by now.  (mount returns ENOTBLK
for a non-devicenode, which is somewhat accurate -- a non-device is not
a block device, after all...)

	-hpa

[PATCH] Hyperv: Export the symbol that tracks hyperv features and recommendations

[Ky Srinivasan]

From: K. Y. Srinivasan <ksrinivasan@novell.com>
Subject:  Export the symbol  for hyperv drivers to access hyperv
features and recommendations.

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>

Index: linux.trees.git/arch/x86/kernel/cpu/mshyperv.c
===================================================================
--- linux.trees.git.orig/arch/x86/kernel/cpu/mshyperv.c	2010-05-18 10:14:02.000000000 -0600
+++ linux.trees.git/arch/x86/kernel/cpu/mshyperv.c	2010-05-18 14:12:11.000000000 -0600
@@ -18,6 +18,7 @@
 #include <asm/mshyperv.h>
 
 struct ms_hyperv_info ms_hyperv;
+EXPORT_SYMBOL(ms_hyperv);
 
 static bool __init ms_hyperv_platform(void)
 {

Re: [PATCH] Hyperv: Export the symbol that tracks hyperv features and recommendations

[Greg KH]

On Wed, May 19, 2010 at 10:54:18AM -0600, Ky Srinivasan wrote:
> 
> From: K. Y. Srinivasan <ksrinivasan@novell.com>
> Subject:  Export the symbol  for hyperv drivers to access hyperv
> features and recommendations.
> 
> Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
> 
> Index: linux.trees.git/arch/x86/kernel/cpu/mshyperv.c
> ===================================================================
> --- linux.trees.git.orig/arch/x86/kernel/cpu/mshyperv.c	2010-05-18 10:14:02.000000000 -0600
> +++ linux.trees.git/arch/x86/kernel/cpu/mshyperv.c	2010-05-18 14:12:11.000000000 -0600
> @@ -18,6 +18,7 @@
>  #include <asm/mshyperv.h>
>  
>  struct ms_hyperv_info ms_hyperv;
> +EXPORT_SYMBOL(ms_hyperv);

EXPORT_SYMBOL_GPL() perhaps?

thanks,

greg k-h