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authorCarsten Otte <cotte@de.ibm.com>2008-03-25 18:47:44 +0100
committerAvi Kivity <avi@qumranet.com>2008-04-27 12:00:50 +0300
commitfa5877439d5a062d91c3abd5a690483bbdb4268e (patch)
tree0bd9c1794134d891678e3602ba78a6facec39d78
parent85f8fffe3c2ab13f13526c46b5471fc22e98ccfe (diff)
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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>
-rw-r--r--arch/s390/Kconfig7
-rw-r--r--arch/s390/kernel/early.c4
-rw-r--r--arch/s390/kernel/setup.c10
-rw-r--r--include/asm-s390/setup.h1
4 files changed, 19 insertions, 3 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9a742ce..8f5f021 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -520,6 +520,13 @@ config ZFCPDUMP
Select this option if you want to build an zfcpdump enabled kernel.
Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
+config S390_GUEST
+bool "s390 guest support (EXPERIMENTAL)"
+ depends on 64BIT && EXPERIMENTAL
+ select VIRTIO
+ select VIRTIO_RING
+ help
+ Select this option if you want to run the kernel under s390 linux
endmenu
source "net/Kconfig"
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 540a67f..68ec408 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -144,6 +144,10 @@ static noinline __init void detect_machine_type(void)
/* Running on a P/390 ? */
if (cpuinfo->cpu_id.machine == 0x7490)
machine_flags |= 4;
+
+ /* Running under KVM ? */
+ if (cpuinfo->cpu_id.version == 0xfe)
+ machine_flags |= 64;
}
#ifdef CONFIG_64BIT
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2f35133..a9d18aa 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -801,9 +801,13 @@ setup_arch(char **cmdline_p)
"This machine has an IEEE fpu\n" :
"This machine has no IEEE fpu\n");
#else /* CONFIG_64BIT */
- printk((MACHINE_IS_VM) ?
- "We are running under VM (64 bit mode)\n" :
- "We are running native (64 bit mode)\n");
+ if (MACHINE_IS_VM)
+ printk("We are running under VM (64 bit mode)\n");
+ else if (MACHINE_IS_KVM) {
+ printk("We are running under KVM (64 bit mode)\n");
+ add_preferred_console("ttyS", 1, NULL);
+ } else
+ printk("We are running native (64 bit mode)\n");
#endif /* CONFIG_64BIT */
/* Save unparsed command line copy for /proc/cmdline */
diff --git a/include/asm-s390/setup.h b/include/asm-s390/setup.h
index a76a6b8..aaf4b51 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)