From: Pavel Tatashin <pasha.tatashin@oracle.com>
To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com,
linux@armlinux.org.uk, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, john.stultz@linaro.org,
sboyd@codeaurora.org, x86@kernel.org,
linux-kernel@vger.kernel.org, mingo@redhat.com,
tglx@linutronix.de, hpa@zytor.com, douly.fnst@cn.fujitsu.com,
peterz@infradead.org, prarit@redhat.com, feng.tang@intel.com,
pmladek@suse.com, gnomes@lxorguk.ukuu.org.uk,
linux-s390@vger.kernel.org, pasha.tatashin@oracle.com,
boris.ostrovsky@oracle.com, jgross@suse.com, pbonzini@redhat.com
Subject: [PATCH v15 04/26] x86/kvmclock: Cleanup the code
Date: Thu, 19 Jul 2018 16:55:23 -0400 [thread overview]
Message-ID: <20180719205545.16512-5-pasha.tatashin@oracle.com> (raw)
In-Reply-To: <20180719205545.16512-1-pasha.tatashin@oracle.com>
From: Thomas Gleixner <tglx@linutronix.de>
- Cleanup the mrs write for wall clock. The type casts to (int) are sloppy
because the wrmsr parameters are u32 and aside of that wrmsrl() already
provides the high/low split for free.
- Remove the pointless get_cpu()/put_cpu() dance from various
functions. Either they are called during early init where CPU is
guaranteed to be 0 or they are already called from non preemptible
context where smp_processor_id() can be used safely
- Simplify the convoluted check for kvmclock in the init function.
- Mark the parameter parsing function __init. No point in keeping it
around.
- Convert to pr_info()
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/kernel/kvmclock.c | 72 ++++++++++++--------------------------
1 file changed, 22 insertions(+), 50 deletions(-)
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index f0a0aef5e9fa..4afb03e49a4f 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -37,7 +37,7 @@ static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME;
static int msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK;
static u64 kvm_sched_clock_offset;
-static int parse_no_kvmclock(char *arg)
+static int __init parse_no_kvmclock(char *arg)
{
kvmclock = 0;
return 0;
@@ -61,13 +61,9 @@ static struct pvclock_wall_clock wall_clock;
static void kvm_get_wallclock(struct timespec64 *now)
{
struct pvclock_vcpu_time_info *vcpu_time;
- int low, high;
int cpu;
- low = (int)slow_virt_to_phys(&wall_clock);
- high = ((u64)slow_virt_to_phys(&wall_clock) >> 32);
-
- native_write_msr(msr_kvm_wall_clock, low, high);
+ wrmsrl(msr_kvm_wall_clock, slow_virt_to_phys(&wall_clock));
cpu = get_cpu();
@@ -117,11 +113,11 @@ static inline void kvm_sched_clock_init(bool stable)
kvm_sched_clock_offset = kvm_clock_read();
pv_time_ops.sched_clock = kvm_sched_clock_read;
- printk(KERN_INFO "kvm-clock: using sched offset of %llu cycles\n",
- kvm_sched_clock_offset);
+ pr_info("kvm-clock: using sched offset of %llu cycles",
+ kvm_sched_clock_offset);
BUILD_BUG_ON(sizeof(kvm_sched_clock_offset) >
- sizeof(((struct pvclock_vcpu_time_info *)NULL)->system_time));
+ sizeof(((struct pvclock_vcpu_time_info *)NULL)->system_time));
}
/*
@@ -135,16 +131,8 @@ static inline void kvm_sched_clock_init(bool stable)
*/
static unsigned long kvm_get_tsc_khz(void)
{
- struct pvclock_vcpu_time_info *src;
- int cpu;
- unsigned long tsc_khz;
-
- cpu = get_cpu();
- src = &hv_clock[cpu].pvti;
- tsc_khz = pvclock_tsc_khz(src);
- put_cpu();
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
- return tsc_khz;
+ return pvclock_tsc_khz(&hv_clock[0].pvti);
}
static void kvm_get_preset_lpj(void)
@@ -161,29 +149,27 @@ static void kvm_get_preset_lpj(void)
bool kvm_check_and_clear_guest_paused(void)
{
- bool ret = false;
struct pvclock_vcpu_time_info *src;
- int cpu = smp_processor_id();
+ bool ret = false;
if (!hv_clock)
return ret;
- src = &hv_clock[cpu].pvti;
+ src = &hv_clock[smp_processor_id()].pvti;
if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) {
src->flags &= ~PVCLOCK_GUEST_STOPPED;
pvclock_touch_watchdogs();
ret = true;
}
-
return ret;
}
struct clocksource kvm_clock = {
- .name = "kvm-clock",
- .read = kvm_clock_get_cycles,
- .rating = 400,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .name = "kvm-clock",
+ .read = kvm_clock_get_cycles,
+ .rating = 400,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
EXPORT_SYMBOL_GPL(kvm_clock);
@@ -199,7 +185,7 @@ static void kvm_register_clock(char *txt)
src = &hv_clock[cpu].pvti;
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);
+ pr_info("kvm-clock: cpu %d, msr %llx, %s", cpu, pa, txt);
}
static void kvm_save_sched_clock_state(void)
@@ -244,20 +230,19 @@ static void kvm_shutdown(void)
void __init kvmclock_init(void)
{
- struct pvclock_vcpu_time_info *vcpu_time;
- int cpu;
u8 flags;
- if (!kvm_para_available())
+ if (!kvm_para_available() || !kvmclock)
return;
- if (kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) {
+ if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) {
msr_kvm_system_time = MSR_KVM_SYSTEM_TIME_NEW;
msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK_NEW;
- } else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)))
+ } else if (!kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) {
return;
+ }
- printk(KERN_INFO "kvm-clock: Using msrs %x and %x",
+ pr_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;
@@ -267,20 +252,15 @@ void __init kvmclock_init(void)
if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))
pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);
- cpu = get_cpu();
- vcpu_time = &hv_clock[cpu].pvti;
- flags = pvclock_read_flags(vcpu_time);
-
+ flags = pvclock_read_flags(&hv_clock[0].pvti);
kvm_sched_clock_init(flags & PVCLOCK_TSC_STABLE_BIT);
- put_cpu();
x86_platform.calibrate_tsc = kvm_get_tsc_khz;
x86_platform.calibrate_cpu = kvm_get_tsc_khz;
x86_platform.get_wallclock = kvm_get_wallclock;
x86_platform.set_wallclock = kvm_set_wallclock;
#ifdef CONFIG_X86_LOCAL_APIC
- x86_cpuinit.early_percpu_clock_init =
- kvm_setup_secondary_clock;
+ x86_cpuinit.early_percpu_clock_init = kvm_setup_secondary_clock;
#endif
x86_platform.save_sched_clock_state = kvm_save_sched_clock_state;
x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state;
@@ -296,20 +276,12 @@ void __init kvmclock_init(void)
int __init kvm_setup_vsyscall_timeinfo(void)
{
#ifdef CONFIG_X86_64
- int cpu;
u8 flags;
- struct pvclock_vcpu_time_info *vcpu_time;
if (!hv_clock)
return 0;
- cpu = get_cpu();
-
- vcpu_time = &hv_clock[cpu].pvti;
- flags = pvclock_read_flags(vcpu_time);
-
- put_cpu();
-
+ flags = pvclock_read_flags(&hv_clock[0].pvti);
if (!(flags & PVCLOCK_TSC_STABLE_BIT))
return 1;
--
2.18.0
next prev parent reply other threads:[~2018-07-19 20:59 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-19 20:55 [PATCH v15 00/26] Early boot time stamps Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 01/26] x86/kvmclock: Remove memblock dependency Pavel Tatashin
2018-07-19 22:21 ` [tip:x86/timers] " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 02/26] x86/kvmclock: Remove page size requirement from wall_clock Pavel Tatashin
2018-07-19 22:22 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 03/26] x86/kvmclock: Decrapify kvm_register_clock() Pavel Tatashin
2018-07-19 22:23 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` Pavel Tatashin [this message]
2018-07-19 22:23 ` [tip:x86/timers] x86/kvmclock: Cleanup the code tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 05/26] x86/kvmclock: Mark variables __initdata and __ro_after_init Pavel Tatashin
2018-07-19 22:24 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 06/26] x86/kvmclock: Move kvmclock vsyscall param and init to kvmclock Pavel Tatashin
2018-07-19 22:24 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 07/26] x86/kvmclock: Switch kvmclock data to a PER_CPU variable Pavel Tatashin
2018-07-19 22:25 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 08/26] x86: text_poke() may access uninitialized struct pages Pavel Tatashin
2018-07-19 22:25 ` [tip:x86/timers] x86/alternatives, jumplabel: Use text_poke_early() before mm_init() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 09/26] x86: initialize static branching early Pavel Tatashin
2018-07-19 22:26 ` [tip:x86/timers] x86/jump_label: Initialize " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 10/26] x86/CPU: Call detect_nopl() only on the BSP Pavel Tatashin
2018-07-19 22:26 ` [tip:x86/timers] " tip-bot for Borislav Petkov
2018-07-19 20:55 ` [PATCH v15 11/26] x86/tsc: redefine notsc to behave as tsc=unstable Pavel Tatashin
2018-07-19 22:27 ` [tip:x86/timers] x86/tsc: Redefine " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 12/26] x86/xen/time: initialize pv xen time in init_hypervisor_platform Pavel Tatashin
2018-07-19 22:27 ` [tip:x86/timers] x86/xen/time: Initialize pv xen time in init_hypervisor_platform() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 13/26] x86/xen/time: output xen sched_clock time from 0 Pavel Tatashin
2018-07-19 22:28 ` [tip:x86/timers] x86/xen/time: Output " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 14/26] s390/time: add read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-19 22:28 ` [tip:x86/timers] s390/time: Add read_persistent_wall_and_boot_offset() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 15/26] time: replace read_boot_clock64() with read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-19 22:29 ` [tip:x86/timers] timekeeping: Replace " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 16/26] time: default boot time offset to local_clock() Pavel Tatashin
2018-07-19 22:29 ` [tip:x86/timers] timekeeping: Default " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 17/26] s390/time: remove read_boot_clock64() Pavel Tatashin
2018-07-19 22:30 ` [tip:x86/timers] s390/time: Remove read_boot_clock64() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 18/26] ARM/time: remove read_boot_clock64() Pavel Tatashin
2018-07-19 22:30 ` [tip:x86/timers] ARM/time: Remove read_boot_clock64() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 19/26] x86/tsc: calibrate tsc only once Pavel Tatashin
2018-07-19 22:31 ` [tip:x86/timers] x86/tsc: Calibrate " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 20/26] x86/tsc: initialize cyc2ns when tsc freq. is determined Pavel Tatashin
2018-07-19 22:31 ` [tip:x86/timers] x86/tsc: Initialize cyc2ns when tsc frequency " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 21/26] x86/tsc: use tsc early Pavel Tatashin
2018-07-19 22:32 ` [tip:x86/timers] x86/tsc: Use TSC as sched clock early tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 22/26] sched: move sched clock initialization and merge with generic clock Pavel Tatashin
2018-07-19 22:32 ` [tip:x86/timers] sched/clock: Move " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 23/26] sched: early boot clock Pavel Tatashin
2018-07-19 22:33 ` [tip:x86/timers] sched/clock: Enable sched clock early tip-bot for Pavel Tatashin
2018-07-24 19:52 ` Guenter Roeck
2018-07-24 20:22 ` Pavel Tatashin
2018-07-25 0:36 ` Pavel Tatashin
2018-07-25 1:24 ` Guenter Roeck
2018-07-25 2:05 ` Pavel Tatashin
2018-07-25 2:41 ` Pavel Tatashin
2018-07-30 12:36 ` Peter Zijlstra
2018-07-30 13:44 ` Pavel Tatashin
2018-07-20 8:09 ` [PATCH v15 23/26] sched: early boot clock Peter Zijlstra
2018-07-20 10:00 ` [tip:x86/timers] sched/clock: Close a hole in sched_clock_init() tip-bot for Peter Zijlstra
2018-11-06 5:42 ` [PATCH v15 23/26] sched: early boot clock Dominique Martinet
2018-11-06 11:35 ` Steven Sistare
2019-01-02 20:20 ` Salvatore Bonaccorso
2019-01-03 21:28 ` Pavel Tatashin
2019-01-03 23:43 ` Dominique Martinet
2019-01-07 18:17 ` Pavel Tatashin
2019-01-07 23:48 ` Dominique Martinet
2019-01-08 1:04 ` Pavel Tatashin
2019-01-08 1:09 ` Dominique Martinet
2019-01-26 2:04 ` Jon DeVree
2019-01-26 16:11 ` Pavel Tatashin
2019-01-04 7:30 ` [PATCH v15 23/26] sched: early boot clock (was Re: Bug#918036: linux: uptime after reboot wrong (kvm-clock related?)) Thorsten Glaser
2018-07-19 20:55 ` [PATCH v15 24/26] sched: use static key for sched_clock_running Pavel Tatashin
2018-07-19 22:33 ` [tip:x86/timers] sched/clock: Use " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 25/26] x86/tsc: split native_calibrate_cpu() into early and late parts Pavel Tatashin
2018-07-19 22:34 ` [tip:x86/timers] x86/tsc: Split " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 26/26] x86/tsc: use tsc_calibrate_cpu_early and pit_hpet_ptimer_calibrate_cpu Pavel Tatashin
2018-07-19 22:35 ` [tip:x86/timers] x86/tsc: Make use of tsc_calibrate_cpu_early() tip-bot for Pavel Tatashin
2018-07-19 22:34 ` [PATCH v15 00/26] Early boot time stamps Thomas Gleixner
[not found] <154644530361.2390.18185252504260044930.reportbug@ci-busyapps.lan.tarent.de>
[not found] ` <20190102163939.GB13145@eldamar.local>
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