x86/kvmclock: Decrapify kvm_register_clock()

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>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Link: https://lkml.kernel.org/r/20180719205545.16512-4-pasha.tatashin@oracle.com

diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 3aea2658323a5ea5c76f2524b7315eb08149d9e1..4c723632c036e4c53f320e5caf39dbf472a41486 100644 (file)
--- 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 a995d7d7164cd8c3ecf79ad1fd52d23a3e84d106..f0a0aef5e9fac3e6c4a4e8ea24a0c9f2eb585edf 100644 (file)
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -187,23 +187,19 @@ 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)
@@ -218,11 +214,7 @@ 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
 
@@ -265,16 +257,11 @@ 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");
        pvclock_set_pvti_cpu0_va(hv_clock);
 
        if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))