x86: Add structs and functions for paravirt clocksource
This patch adds structs for the paravirt clocksource ABI
used by both xen and kvm (pvclock-abi.h).
It also adds some helper functions to read system time and
wall clock time from a paravirtual clocksource (pvclock.[ch]).
They are based on the xen code. They are enabled using
CONFIG_PARAVIRT_CLOCK.
Subsequent patches of this series will put the code in use.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 52e18e6..f94bca6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -410,6 +410,10 @@
over full virtualization. However, when run without a hypervisor
the kernel is theoretically slower and slightly larger.
+config PARAVIRT_CLOCK
+ bool
+ default n
+
endif
config MEMTEST_BOOTPARAM