[PATCH v14 03/25] x86/kvmclock: Decrapify kvm_register_clock()

Pavel Tatashin
2018-07-18T02:21:49Z

From: Thomas Gleixner <tglx@linutronix.de>

The return value is pointless because the wrmsr cannot fail if
KVM_FEATURE_CLOCKSOURCE or KVM_FEATURE_CLOCKSOURCE2 are set.

kvm_register_clock() is only called locally so wants to be static.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_para.h | 1 -
arch/x86/kernel/kvmclock.c | 34 +++++++++++----------------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 3aea2658323a..4c723632c036 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -7,7 +7,6 @@
#include <uapi/asm/kvm_para.h>

extern void kvmclock_init(void);
-extern int kvm_register_clock(char *txt);

#ifdef CONFIG_KVM_GUEST
bool kvm_check_and_clear_guest_paused(void);
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index e9863639312c..cbf0a6b9217b 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -186,23 +186,19 @@ struct clocksource kvm_clock = {
};
EXPORT_SYMBOL_GPL(kvm_clock);

-int kvm_register_clock(char *txt)
+static void kvm_register_clock(char *txt)
{
- int cpu = smp_processor_id();
- int low, high, ret;
struct pvclock_vcpu_time_info *src;
+ int cpu = smp_processor_id();
+ u64 pa;

if (!hv_clock)
- return 0;
+ return;

src = &hv_clock[cpu].pvti;
- low = (int)slow_virt_to_phys(src) | 1;
- high = ((u64)slow_virt_to_phys(src) >> 32);
- ret = native_write_msr_safe(msr_kvm_system_time, low, high);
- printk(KERN_INFO "kvm-clock: cpu %d, msr %x:%x, %s\n",
- cpu, high, low, txt);
-
- return ret;
+ pa = slow_virt_to_phys(src) | 0x01ULL;
+ wrmsrl(msr_kvm_system_time, pa);
+ pr_info("kvm-clock: cpu %d, msr %llx, %s\n", cpu, pa, txt);
}

static void kvm_save_sched_clock_state(void)
@@ -217,11 +213,7 @@ static void kvm_restore_sched_clock_state(void)
#ifdef CONFIG_X86_LOCAL_APIC
static void kvm_setup_secondary_clock(void)
{
- /*
- * Now that the first cpu already had this clocksource initialized,
- * we shouldn't fail.
- */
- WARN_ON(kvm_register_clock("secondary cpu clock"));
+ kvm_register_clock("secondary cpu clock");
}
#endif

@@ -264,16 +256,12 @@ void __init kvmclock_init(void)
} else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)))
return;

- hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem;
-
- if (kvm_register_clock("primary cpu clock")) {
- hv_clock = NULL;
- return;
- }
-
printk(KERN_INFO "kvm-clock: Using msrs %x and %x",
msr_kvm_system_time, msr_kvm_wall_clock);

+ hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem;
+ kvm_register_clock("primary cpu clock");
+
if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))
pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);

--
2.18.0