s390: KVM guest: detect when running on kvm

This patch adds functionality to detect if the kernel runs under the KVM
hypervisor. A macro MACHINE_IS_KVM is exported for device drivers. This
allows drivers to skip device detection if the systems runs non-virtualized.
We also define a preferred console to avoid having the ttyS0, which is a line
mode only console.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-s390/setup.h b/include/asm-s390/setup.h
index a76a6b8fd887..aaf4b518b940 100644
--- a/include/asm-s390/setup.h
+++ b/include/asm-s390/setup.h
@@ -62,6 +62,7 @@ extern unsigned long machine_flags;
 #define MACHINE_IS_VM           (machine_flags & 1)
 #define MACHINE_IS_P390         (machine_flags & 4)
 #define MACHINE_HAS_MVPG        (machine_flags & 16)
+#define MACHINE_IS_KVM          (machine_flags & 64)
 #define MACHINE_HAS_IDTE        (machine_flags & 128)
 #define MACHINE_HAS_DIAG9C      (machine_flags & 256)