By doing that, add tsc clocksource to a list of KVM clocksources providing valid cycle values, meaning that KVM can use its masterclock.
This is a part of the work aiming to move to a more simple scheme of masterclock related values calculation in KVM. Signed-off-by: Denis Plotnikov <[email protected]> --- arch/x86/kernel/tsc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 796d96b..8786454 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1036,6 +1036,15 @@ static void tsc_cs_tick_stable(struct clocksource *cs) sched_clock_tick_stable(); } +static bool tsc_read_with_stamp(struct clocksource *cs, + u64 *cycles, u64 *cycles_stamp) +{ + u64 tsc = read_tsc(cs); + *cycles = tsc; + *cycles_stamp = tsc; + return true; +} + /* * .mask MUST be CLOCKSOURCE_MASK(64). See comment above read_tsc() */ @@ -1043,6 +1052,7 @@ static struct clocksource clocksource_tsc = { .name = "tsc", .rating = 300, .read = read_tsc, + .read_with_stamp = tsc_read_with_stamp, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, -- 2.7.4
