[PATCH 4.14 098/159] x86/paravirt: Provide a way to check for hypervisors

Greg Kroah-Hartman
2017-12-22T09:35:14Z

From: Thomas Gleixner <tglx@linutronix.de>

commit 79cc74155218316b9a5d28577c7077b2adba8e58 upstream.

There is no generic way to test whether a kernel is running on a specific
hypervisor. But that's required to prevent the upcoming user address space
separation feature in certain guest modes.

Make the hypervisor type enum unconditionally available and provide a
helper function which allows to test for a specific type.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.912938129@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/include/asm/hypervisor.h | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -20,16 +20,7 @@
#ifndef _ASM_X86_HYPERVISOR_H
#define _ASM_X86_HYPERVISOR_H

-#ifdef CONFIG_HYPERVISOR_GUEST
-
-#include <asm/kvm_para.h>
-#include <asm/x86_init.h>
-#include <asm/xen/hypervisor.h>
-
-/*
- * x86 hypervisor information
- */
-
+/* x86 hypervisor types */
enum x86_hypervisor_type {
X86_HYPER_NATIVE = 0,
X86_HYPER_VMWARE,
@@ -39,6 +30,12 @@ enum x86_hypervisor_type {
X86_HYPER_KVM,
};

+#ifdef CONFIG_HYPERVISOR_GUEST
+
+#include <asm/kvm_para.h>
+#include <asm/x86_init.h>
+#include <asm/xen/hypervisor.h>
+
struct hypervisor_x86 {
/* Hypervisor name */
const char *name;
@@ -58,7 +55,15 @@ struct hypervisor_x86 {

extern enum x86_hypervisor_type x86_hyper_type;
extern void init_hypervisor_platform(void);
+static inline bool hypervisor_is_type(enum x86_hypervisor_type type)
+{
+ return x86_hyper_type == type;
+}
#else
static inline void init_hypervisor_platform(void) { }
+static inline bool hypervisor_is_type(enum x86_hypervisor_type type)
+{
+ return type == X86_HYPER_NATIVE;
+}
#endif /* CONFIG_HYPERVISOR_GUEST */
#endif /* _ASM_X86_HYPERVISOR_H */