x86: KVM guest: paravirtualized clocksource

This is the guest part of kvm clock implementation
It does not do tsc-only timing, as tsc can have deltas
between cpus, and it did not seem worthy to me to keep
adjusting them.

We do use it, however, for fine-grained adjustment.

Other than that, time comes from the host.

[randy dunlap: add missing include]
[randy dunlap: disallow on Voyager or Visual WS]

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 60e64c8eee92..8a9213c023ef 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -42,6 +42,7 @@
 #include <linux/ctype.h>
 #include <linux/uaccess.h>
 #include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
 
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
@@ -384,6 +385,10 @@ void __init setup_arch(char **cmdline_p)
 
         io_delay_init();
 
+#ifdef CONFIG_KVM_CLOCK
+        kvmclock_init();
+#endif
+
 #ifdef CONFIG_SMP
         /* setup to use the early static init tables during kernel startup */
         x86_cpu_to_apicid_early_ptr = (void *)x86_cpu_to_apicid_init;