Move the handling of unstable PV clocks, of which kvmclock is the only
example, into paravirt_set_sched_clock(). This will allow modifying
paravirt_set_sched_clock() to keep using the TSC for sched_clock in
certain scenarios without unintentionally marking the TSC-based clock as
unstable.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/paravirt.h | 7 ++++++-
arch/x86/kernel/kvmclock.c | 5 +----
arch/x86/kernel/paravirt.c | 6 +++++-
3 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 041aff51eb50..cfceabd5f7e1 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -28,7 +28,12 @@ u64 dummy_sched_clock(void);
DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock);
-void paravirt_set_sched_clock(u64 (*func)(void));
+void __paravirt_set_sched_clock(u64 (*func)(void), bool stable);
+
+static inline void paravirt_set_sched_clock(u64 (*func)(void))
+{
+ __paravirt_set_sched_clock(func, true);
+}
static __always_inline u64 paravirt_sched_clock(void)
{
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index b41ac7f27b9f..890535ddc059 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -12,7 +12,6 @@
#include <linux/hardirq.h>
#include <linux/cpuhotplug.h>
#include <linux/sched.h>
-#include <linux/sched/clock.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/set_memory.h>
@@ -93,10 +92,8 @@ static noinstr u64 kvm_sched_clock_read(void)
static inline void kvm_sched_clock_init(bool stable)
{
- if (!stable)
- clear_sched_clock_stable();
kvm_sched_clock_offset = kvm_clock_read();
- paravirt_set_sched_clock(kvm_sched_clock_read);
+ __paravirt_set_sched_clock(kvm_sched_clock_read, stable);
pr_info("kvm-clock: using sched offset of %llu cycles",
kvm_sched_clock_offset);
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 1ccaa3397a67..55c819673a9d 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -14,6 +14,7 @@
#include <linux/highmem.h>
#include <linux/kprobes.h>
#include <linux/pgtable.h>
+#include <linux/sched/clock.h>
#include <linux/static_call.h>
#include <asm/bug.h>
@@ -85,8 +86,11 @@ static u64 native_steal_clock(int cpu)
DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
-void paravirt_set_sched_clock(u64 (*func)(void))
+void __paravirt_set_sched_clock(u64 (*func)(void), bool stable)
{
+ if (!stable)
+ clear_sched_clock_stable();
+
static_call_update(pv_sched_clock, func);
}
--
2.48.1.362.g079036d154-goog