All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.
read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.
Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
gcc noticed (when using -Wempty-body) that our use of
lock_cmos() and unlock_cmos() in
arch/x86/include/asm/mach_traps.h is potentially problematic :
arch/x86/include/asm/mach_traps.h:32:15: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]
arch/x86/include/asm/mach_traps.h:40:16: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]
Let's just use the standard 'do {} while (0)' solution. That
shuts up gcc and also prevents future problems if the macros
should end up being used in a similar situation elsewhere.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1112180103130.21784@swampdragon.chaosbits.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:
a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
