提交 146c394d 编写于 作者: T Thomas Gleixner

x86/kvmclock: Cleanup the code

- 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: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: NPaolo 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/20180719205545.16512-5-pasha.tatashin@oracle.com
上级 7a5ddc8f
...@@ -37,7 +37,7 @@ static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME; ...@@ -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 int msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK;
static u64 kvm_sched_clock_offset; static u64 kvm_sched_clock_offset;
static int parse_no_kvmclock(char *arg) static int __init parse_no_kvmclock(char *arg)
{ {
kvmclock = 0; kvmclock = 0;
return 0; return 0;
...@@ -61,13 +61,9 @@ static struct pvclock_wall_clock wall_clock; ...@@ -61,13 +61,9 @@ static struct pvclock_wall_clock wall_clock;
static void kvm_get_wallclock(struct timespec64 *now) static void kvm_get_wallclock(struct timespec64 *now)
{ {
struct pvclock_vcpu_time_info *vcpu_time; struct pvclock_vcpu_time_info *vcpu_time;
int low, high;
int cpu; int cpu;
low = (int)slow_virt_to_phys(&wall_clock); wrmsrl(msr_kvm_wall_clock, slow_virt_to_phys(&wall_clock));
high = ((u64)slow_virt_to_phys(&wall_clock) >> 32);
native_write_msr(msr_kvm_wall_clock, low, high);
cpu = get_cpu(); cpu = get_cpu();
...@@ -117,11 +113,11 @@ static inline void kvm_sched_clock_init(bool stable) ...@@ -117,11 +113,11 @@ static inline void kvm_sched_clock_init(bool stable)
kvm_sched_clock_offset = kvm_clock_read(); kvm_sched_clock_offset = kvm_clock_read();
pv_time_ops.sched_clock = kvm_sched_clock_read; pv_time_ops.sched_clock = kvm_sched_clock_read;
printk(KERN_INFO "kvm-clock: using sched offset of %llu cycles\n", pr_info("kvm-clock: using sched offset of %llu cycles",
kvm_sched_clock_offset); kvm_sched_clock_offset);
BUILD_BUG_ON(sizeof(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) ...@@ -135,16 +131,8 @@ static inline void kvm_sched_clock_init(bool stable)
*/ */
static unsigned long kvm_get_tsc_khz(void) 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); 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) static void kvm_get_preset_lpj(void)
...@@ -161,29 +149,27 @@ 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 kvm_check_and_clear_guest_paused(void)
{ {
bool ret = false;
struct pvclock_vcpu_time_info *src; struct pvclock_vcpu_time_info *src;
int cpu = smp_processor_id(); bool ret = false;
if (!hv_clock) if (!hv_clock)
return ret; return ret;
src = &hv_clock[cpu].pvti; src = &hv_clock[smp_processor_id()].pvti;
if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) { if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) {
src->flags &= ~PVCLOCK_GUEST_STOPPED; src->flags &= ~PVCLOCK_GUEST_STOPPED;
pvclock_touch_watchdogs(); pvclock_touch_watchdogs();
ret = true; ret = true;
} }
return ret; return ret;
} }
struct clocksource kvm_clock = { struct clocksource kvm_clock = {
.name = "kvm-clock", .name = "kvm-clock",
.read = kvm_clock_get_cycles, .read = kvm_clock_get_cycles,
.rating = 400, .rating = 400,
.mask = CLOCKSOURCE_MASK(64), .mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS, .flags = CLOCK_SOURCE_IS_CONTINUOUS,
}; };
EXPORT_SYMBOL_GPL(kvm_clock); EXPORT_SYMBOL_GPL(kvm_clock);
...@@ -199,7 +185,7 @@ static void kvm_register_clock(char *txt) ...@@ -199,7 +185,7 @@ static void kvm_register_clock(char *txt)
src = &hv_clock[cpu].pvti; src = &hv_clock[cpu].pvti;
pa = slow_virt_to_phys(src) | 0x01ULL; pa = slow_virt_to_phys(src) | 0x01ULL;
wrmsrl(msr_kvm_system_time, pa); 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) static void kvm_save_sched_clock_state(void)
...@@ -244,20 +230,19 @@ static void kvm_shutdown(void) ...@@ -244,20 +230,19 @@ static void kvm_shutdown(void)
void __init kvmclock_init(void) void __init kvmclock_init(void)
{ {
struct pvclock_vcpu_time_info *vcpu_time;
int cpu;
u8 flags; u8 flags;
if (!kvm_para_available()) if (!kvm_para_available() || !kvmclock)
return; 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_system_time = MSR_KVM_SYSTEM_TIME_NEW;
msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK_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; 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); msr_kvm_system_time, msr_kvm_wall_clock);
hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem; hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem;
...@@ -267,20 +252,15 @@ void __init kvmclock_init(void) ...@@ -267,20 +252,15 @@ void __init kvmclock_init(void)
if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT)) if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))
pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);
cpu = get_cpu(); flags = pvclock_read_flags(&hv_clock[0].pvti);
vcpu_time = &hv_clock[cpu].pvti;
flags = pvclock_read_flags(vcpu_time);
kvm_sched_clock_init(flags & PVCLOCK_TSC_STABLE_BIT); kvm_sched_clock_init(flags & PVCLOCK_TSC_STABLE_BIT);
put_cpu();
x86_platform.calibrate_tsc = kvm_get_tsc_khz; x86_platform.calibrate_tsc = kvm_get_tsc_khz;
x86_platform.calibrate_cpu = kvm_get_tsc_khz; x86_platform.calibrate_cpu = kvm_get_tsc_khz;
x86_platform.get_wallclock = kvm_get_wallclock; x86_platform.get_wallclock = kvm_get_wallclock;
x86_platform.set_wallclock = kvm_set_wallclock; x86_platform.set_wallclock = kvm_set_wallclock;
#ifdef CONFIG_X86_LOCAL_APIC #ifdef CONFIG_X86_LOCAL_APIC
x86_cpuinit.early_percpu_clock_init = x86_cpuinit.early_percpu_clock_init = kvm_setup_secondary_clock;
kvm_setup_secondary_clock;
#endif #endif
x86_platform.save_sched_clock_state = kvm_save_sched_clock_state; x86_platform.save_sched_clock_state = kvm_save_sched_clock_state;
x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state; x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state;
...@@ -296,20 +276,12 @@ void __init kvmclock_init(void) ...@@ -296,20 +276,12 @@ void __init kvmclock_init(void)
int __init kvm_setup_vsyscall_timeinfo(void) int __init kvm_setup_vsyscall_timeinfo(void)
{ {
#ifdef CONFIG_X86_64 #ifdef CONFIG_X86_64
int cpu;
u8 flags; u8 flags;
struct pvclock_vcpu_time_info *vcpu_time;
if (!hv_clock) if (!hv_clock)
return 0; return 0;
cpu = get_cpu(); flags = pvclock_read_flags(&hv_clock[0].pvti);
vcpu_time = &hv_clock[cpu].pvti;
flags = pvclock_read_flags(vcpu_time);
put_cpu();
if (!(flags & PVCLOCK_TSC_STABLE_BIT)) if (!(flags & PVCLOCK_TSC_STABLE_BIT))
return 1; return 1;
......
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