x86: Detect running on a Microsoft HyperV system

This patch integrates HyperV detection within the framework currently
used by VmWare. With this patch, we can avoid having to replicate the
HyperV detection code in each of the Microsoft HyperV drivers.

Reworked and tweaked by Greg K-H to build properly.

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
LKML-Reference: <20100506190841.GA1605@kroah.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 75 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index c202b62..3a785da 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -14,7 +14,7 @@ CFLAGS_common.o		:= $(nostackp)
 
 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 sched.o
+obj-y			+= vmware.o hypervisor.o sched.o mshyperv.o
 
 obj-$(CONFIG_X86_32)	+= bugs.o cmpxchg.o
 obj-$(CONFIG_X86_64)	+= bugs_64.o
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 08be922..de3f4e0 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -23,6 +23,7 @@
 
 #include <asm/processor.h>
 #include <asm/vmware.h>
+#include <asm/mshyperv.h>
 #include <asm/hypervisor.h>
 
 static inline void __cpuinit
@@ -30,6 +31,8 @@ detect_hypervisor_vendor(struct cpuinfo_x86 *c)
 {
 	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;
 }
@@ -37,10 +40,11 @@ detect_hypervisor_vendor(struct cpuinfo_x86 *c)
 static inline void __cpuinit
 hypervisor_set_feature_bits(struct cpuinfo_x86 *c)
 {
-	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE) {
+	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
 		vmware_set_feature_bits(c);
-		return;
-	}
+	else if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_MSFT)
+		ms_hyperv_set_feature_bits(c);
+	return;
 }
 
 void __cpuinit init_hypervisor(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
new file mode 100644
index 0000000..2443b61
--- /dev/null
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -0,0 +1,67 @@
+/*
+ * HyperV  Detection code.
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.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/types.h>
+#include <asm/processor.h>
+#include <asm/hyperv.h>
+#include <asm/mshyperv.h>
+
+
+int ms_hyperv_platform(void)
+{
+	u32 eax, ebx, ecx, edx;
+	char hyp_signature[13];
+
+	cpuid(1, &eax, &ebx, &ecx, &edx);
+	if (!(ecx & HYPERV_HYPERVISOR_PRESENT_BIT))
+		return 0;
+
+	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;
+
+	if ((eax < HYPERV_CPUID_MIN) || (memcmp("Microsoft Hv", hyp_signature, 12)))
+		return 0;
+	return 1;
+}
+
+void __cpuinit ms_hyperv_set_feature_bits(struct cpuinfo_x86 *c)
+{
+	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.
+	 */
+	cpuid(HYPERV_CPUID_FEATURES, &eax, &ebx, &ecx, &edx);
+	c->x86_hyper_features |= (eax & 0x1ff);
+
+	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);
+}