Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 013fe3d..904494b 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -1,19 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* KVM paravirtual clock driver. A clocksource implementation
Copyright (C) 2008 Glauber de Oliveira Costa, Red Hat Inc.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/clocksource.h>
@@ -117,14 +104,10 @@
static inline void kvm_sched_clock_init(bool stable)
{
- if (!stable) {
- pv_time_ops.sched_clock = kvm_clock_read;
+ if (!stable)
clear_sched_clock_stable();
- return;
- }
-
kvm_sched_clock_offset = kvm_clock_read();
- pv_time_ops.sched_clock = kvm_sched_clock_read;
+ pv_ops.time.sched_clock = kvm_sched_clock_read;
pr_info("kvm-clock: using sched offset of %llu cycles",
kvm_sched_clock_offset);
@@ -368,6 +351,20 @@
machine_ops.crash_shutdown = kvm_crash_shutdown;
#endif
kvm_get_preset_lpj();
+
+ /*
+ * X86_FEATURE_NONSTOP_TSC is TSC runs at constant rate
+ * with P/T states and does not stop in deep C-states.
+ *
+ * Invariant TSC exposed by host means kvmclock is not necessary:
+ * can use TSC as clocksource.
+ *
+ */
+ if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
+ boot_cpu_has(X86_FEATURE_NONSTOP_TSC) &&
+ !check_tsc_unstable())
+ kvm_clock.rating = 299;
+
clocksource_register_hz(&kvm_clock, NSEC_PER_SEC);
pv_info.name = "KVM";
}