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>

8 files changed, 117 insertions, 107 deletions

diff --git a/arch/x86/include/asm/hyperv.h b/arch/x86/include/asm/hyperv.h
index 46040473e122..5df477ac3af7 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 b78c0941e422..70abda7058c8 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 6cd8101d1344..79ce5685ab64 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 597c041bd124..e4f1dfb2d05b 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 e49ed6d2fd4e..000000000000
--- 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 de3f4e0ce8eb..87381759d3cb 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);
+        const struct hypervisor_x86 *h, * const *p;
+
+        for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
+                h = *p;