提交 409771d2 编写于 作者: S Stefano Stabellini 提交者: Jeremy Fitzhardinge

x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.

Use xen_vcpuop_clockevent instead of hpet and APIC timers as main
clockevent device on all vcpus, use the xen wallclock time as wallclock
instead of rtc and use xen_clocksource as clocksource.
The pv clock algorithm needs to work correctly for the xen_clocksource
and xen wallclock to be usable, only modern Xen versions offer a
reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock).

Using the hpet as clocksource means a VMEXIT every time we read/write to
the hpet mmio addresses, pvclock give us a better rating without
VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDon Dutile <ddutile@redhat.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
上级 99ad198c
......@@ -935,10 +935,6 @@ static const struct pv_init_ops xen_init_ops __initdata = {
.patch = xen_patch,
};
static const struct pv_time_ops xen_time_ops __initdata = {
.sched_clock = xen_sched_clock,
};
static const struct pv_cpu_ops xen_cpu_ops __initdata = {
.cpuid = xen_cpuid,
......@@ -1076,7 +1072,6 @@ asmlinkage void __init xen_start_kernel(void)
/* Install Xen paravirt ops */
pv_info = xen_info;
pv_init_ops = xen_init_ops;
pv_time_ops = xen_time_ops;
pv_cpu_ops = xen_cpu_ops;
pv_apic_ops = xen_apic_ops;
......@@ -1084,13 +1079,7 @@ asmlinkage void __init xen_start_kernel(void)
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;
x86_init.timers.timer_init = xen_time_init;
x86_init.timers.setup_percpu_clockev = x86_init_noop;
x86_cpuinit.setup_percpu_clockev = x86_init_noop;
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
x86_platform.set_wallclock = xen_set_wallclock;
xen_init_time_ops();
/*
* Set up some pagetable state before starting to set any ptes.
......@@ -1327,6 +1316,7 @@ static void __init xen_hvm_guest_init(void)
register_cpu_notifier(&xen_hvm_cpu_notifier);
have_vcpu_info_placement = 0;
x86_init.irqs.intr_init = xen_init_IRQ;
xen_hvm_init_time_ops();
}
static bool __init xen_hvm_platform(void)
......
......@@ -28,8 +28,14 @@ void xen_pre_suspend(void)
void xen_hvm_post_suspend(int suspend_cancelled)
{
int cpu;
xen_hvm_init_shared_info();
xen_callback_vector();
if (xen_feature(XENFEAT_hvm_safe_pvclock)) {
for_each_online_cpu(cpu) {
xen_setup_runstate_info(cpu);
}
}
}
void xen_post_suspend(int suspend_cancelled)
......
......@@ -20,6 +20,7 @@
#include <asm/xen/hypercall.h>
#include <xen/events.h>
#include <xen/features.h>
#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>
......@@ -160,7 +161,7 @@ static void do_stolen_accounting(void)
* nanoseconds, which is nanoseconds the VCPU spent in RUNNING+BLOCKED
* states.
*/
unsigned long long xen_sched_clock(void)
static unsigned long long xen_sched_clock(void)
{
struct vcpu_runstate_info state;
cycle_t now;
......@@ -195,7 +196,7 @@ unsigned long long xen_sched_clock(void)
/* Get the TSC speed from Xen */
unsigned long xen_tsc_khz(void)
static unsigned long xen_tsc_khz(void)
{
struct pvclock_vcpu_time_info *info =
&HYPERVISOR_shared_info->vcpu_info[0].time;
......@@ -230,7 +231,7 @@ static void xen_read_wallclock(struct timespec *ts)
put_cpu_var(xen_vcpu);
}
unsigned long xen_get_wallclock(void)
static unsigned long xen_get_wallclock(void)
{
struct timespec ts;
......@@ -238,7 +239,7 @@ unsigned long xen_get_wallclock(void)
return ts.tv_sec;
}
int xen_set_wallclock(unsigned long now)
static int xen_set_wallclock(unsigned long now)
{
/* do nothing for domU */
return -1;
......@@ -473,7 +474,11 @@ void xen_timer_resume(void)
}
}
__init void xen_time_init(void)
static const struct pv_time_ops xen_time_ops __initdata = {
.sched_clock = xen_sched_clock,
};
static __init void xen_time_init(void)
{
int cpu = smp_processor_id();
struct timespec tp;
......@@ -497,3 +502,46 @@ __init void xen_time_init(void)
xen_setup_timer(cpu);
xen_setup_cpu_clockevents();
}
__init void xen_init_time_ops(void)
{
pv_time_ops = xen_time_ops;
x86_init.timers.timer_init = xen_time_init;
x86_init.timers.setup_percpu_clockev = x86_init_noop;
x86_cpuinit.setup_percpu_clockev = x86_init_noop;
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
x86_platform.set_wallclock = xen_set_wallclock;
}
static void xen_hvm_setup_cpu_clockevents(void)
{
int cpu = smp_processor_id();
xen_setup_runstate_info(cpu);
xen_setup_timer(cpu);
xen_setup_cpu_clockevents();
}
__init void xen_hvm_init_time_ops(void)
{
/* vector callback is needed otherwise we cannot receive interrupts
* on cpu > 0 */
if (!xen_have_vector_callback && num_present_cpus() > 1)
return;
if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
"disable pv timer\n");
return;
}
pv_time_ops = xen_time_ops;
x86_init.timers.setup_percpu_clockev = xen_time_init;
x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents;
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
x86_platform.set_wallclock = xen_set_wallclock;
}
......@@ -49,11 +49,8 @@ void xen_setup_runstate_info(int cpu);
void xen_teardown_timer(int cpu);
cycle_t xen_clocksource_read(void);
void xen_setup_cpu_clockevents(void);
unsigned long xen_tsc_khz(void);
void __init xen_time_init(void);
unsigned long xen_get_wallclock(void);
int xen_set_wallclock(unsigned long time);
unsigned long long xen_sched_clock(void);
void __init xen_init_time_ops(void);
void __init xen_hvm_init_time_ops(void);
irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
......
......@@ -44,6 +44,9 @@
/* x86: Does this Xen host support the HVM callback vector type? */
#define XENFEAT_hvm_callback_vector 8
/* x86: pvclock algorithm is safe to use on HVM */
#define XENFEAT_hvm_safe_pvclock 9
#define XENFEAT_NR_SUBMAPS 1
#endif /* __XEN_PUBLIC_FEATURES_H__ */
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