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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Radim Krcmar <rkrcmar@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juergen Gross <jgross@suse.com>,
	Pavel Tatashin <pasha.tatashin@oracle.com>,
	steven.sistare@oracle.com, daniel.m.jordan@oracle.com,
	x86@kernel.org, kvm@vger.kernel.org
Subject: [patch 3/7] x86/kvmclock: Decrapify kvm_register_clock()
Date: Fri, 06 Jul 2018 18:13:10 +0200	[thread overview]
Message-ID: <20180706162049.482199075@linutronix.de> (raw)
In-Reply-To: 20180706161307.733337643@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>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
---
 arch/x86/include/asm/kvm_para.h |    1 -
 arch/x86/kernel/kvmclock.c      |   35 +++++++++++------------------------
 2 files changed, 11 insertions(+), 25 deletions(-)

--- 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);
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -186,23 +186,18 @@ 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;
-
-	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;
 
-	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 +212,7 @@ static void kvm_restore_sched_clock_stat
 #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 +255,12 @@ 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);
 



  parent reply	other threads:[~2018-07-06 16:25 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-06 16:13 [patch 0/7] x86/kvmclock: Remove memblock dependency and further cleanups Thomas Gleixner
2018-07-06 16:13 ` [patch 1/7] x86/kvmclock: Remove memblock dependency Thomas Gleixner
2018-07-06 16:13 ` [patch 2/7] x86/kvmclock: Remove page size requirement from wall_clock Thomas Gleixner
2018-07-12  2:15   ` Pavel Tatashin
2018-07-06 16:13 ` Thomas Gleixner [this message]
2018-07-06 17:38   ` [patch 3/7] x86/kvmclock: Decrapify kvm_register_clock() Paolo Bonzini
2018-07-06 17:39     ` Thomas Gleixner
2018-07-12  2:24   ` Pavel Tatashin
2018-07-06 16:13 ` [patch 4/7] x86/kvmclock: Cleanup the code Thomas Gleixner
2018-07-06 17:39   ` Paolo Bonzini
2018-07-09  9:05   ` Peter Zijlstra
2018-07-09 10:03     ` Thomas Gleixner
2018-07-09 11:32     ` Paolo Bonzini
2018-07-06 16:13 ` [patch 5/7] x86/kvmclock: Mark variables __initdata and __ro_after_init Thomas Gleixner
2018-07-12  2:31   ` Pavel Tatashin
2018-07-06 16:13 ` [patch 6/7] x86/kvmclock: Move kvmclock vsyscall param and init to kvmclock Thomas Gleixner
2018-07-06 17:43   ` Paolo Bonzini
2018-07-06 19:23     ` Thomas Gleixner
2018-07-12  2:52   ` Pavel Tatashin
2018-07-06 16:13 ` [patch 7/7] x86/kvmclock: Switch kvmclock data to a PER_CPU variable Thomas Gleixner
2018-07-12  3:12   ` Pavel Tatashin
2018-07-06 17:47 ` [patch 0/7] x86/kvmclock: Remove memblock dependency and further cleanups Paolo Bonzini
2018-07-06 23:51   ` Brijesh Singh
2018-07-09  9:22 ` [patch 8/7] x86/kvmclock: Avoid TSC recalibration Peter Zijlstra
2018-07-12  2:12 ` [patch 0/7] x86/kvmclock: Remove memblock dependency and further cleanups Pavel Tatashin
2018-07-13 22:51   ` Thomas Gleixner
2018-07-14  0:20     ` Pavel Tatashin

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