Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm (919c0d14) · Commits · 戴 / test

arch/x86/Kconfig

+5 −0

Original line number	Diff line number	Diff line
		@@ -383,6 +383,7 @@ config VMI
		config KVM_CLOCK
		bool "KVM paravirtualized clock"
		select PARAVIRT
		select PARAVIRT_CLOCK
		depends on !(X86_VISWS \|\| X86_VOYAGER)
		help
		Turning on this option will allow you to run a paravirtualized clock
		@@ -410,6 +411,10 @@ config PARAVIRT
		over full virtualization. However, when run without a hypervisor
		the kernel is theoretically slower and slightly larger.

		config PARAVIRT_CLOCK
		bool
		default n

		endif

		config MEMTEST_BOOTPARAM

arch/x86/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -82,6 +82,7 @@ obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o
		obj-$(CONFIG_KVM_GUEST) += kvm.o
		obj-$(CONFIG_KVM_CLOCK) += kvmclock.o
		obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o
		obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o

		obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o

arch/x86/kernel/kvmclock.c

+33 −56

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@

		#include <linux/clocksource.h>
		#include <linux/kvm_para.h>
		#include <asm/pvclock.h>
		#include <asm/arch_hooks.h>
		#include <asm/msr.h>
		#include <asm/apic.h>
		@@ -36,18 +37,9 @@ static int parse_no_kvmclock(char *arg)
		early_param("no-kvmclock", parse_no_kvmclock);

		/* The hypervisor will put information about time periodically here */
		static DEFINE_PER_CPU_SHARED_ALIGNED(struct kvm_vcpu_time_info, hv_clock);
		#define get_clock(cpu, field) per_cpu(hv_clock, cpu).field
		static DEFINE_PER_CPU_SHARED_ALIGNED(struct pvclock_vcpu_time_info, hv_clock);
		static struct pvclock_wall_clock wall_clock;

		static inline u64 kvm_get_delta(u64 last_tsc)
		{
		int cpu = smp_processor_id();
		u64 delta = native_read_tsc() - last_tsc;
		return (delta * get_clock(cpu, tsc_to_system_mul)) >> KVM_SCALE;
		}

		static struct kvm_wall_clock wall_clock;
		static cycle_t kvm_clock_read(void);
		/*
		* The wallclock is the time of day when we booted. Since then, some time may
		* have elapsed since the hypervisor wrote the data. So we try to account for
		@@ -55,64 +47,37 @@ static cycle_t kvm_clock_read(void);
		*/
		static unsigned long kvm_get_wallclock(void)
		{
		u32 wc_sec, wc_nsec;
		u64 delta;
		struct pvclock_vcpu_time_info *vcpu_time;
		struct timespec ts;
		int version, nsec;
		int low, high;

		low = (int)__pa(&wall_clock);
		high = ((u64)__pa(&wall_clock) >> 32);
		native_write_msr(MSR_KVM_WALL_CLOCK, low, high);

		delta = kvm_clock_read();
		vcpu_time = &get_cpu_var(hv_clock);
		pvclock_read_wallclock(&wall_clock, vcpu_time, &ts);
		put_cpu_var(hv_clock);

		native_write_msr(MSR_KVM_WALL_CLOCK, low, high);
		do {
		version = wall_clock.wc_version;
		rmb();
		wc_sec = wall_clock.wc_sec;
		wc_nsec = wall_clock.wc_nsec;
		rmb();
		} while ((wall_clock.wc_version != version) \|\| (version & 1));

		delta = kvm_clock_read() - delta;
		delta += wc_nsec;
		nsec = do_div(delta, NSEC_PER_SEC);
		set_normalized_timespec(&ts, wc_sec + delta, nsec);
		/*
		* Of all mechanisms of time adjustment I've tested, this one
		* was the champion!
		*/
		return ts.tv_sec + 1;
		return ts.tv_sec;
		}

		static int kvm_set_wallclock(unsigned long now)
		{
		return 0;
		return -1;
		}

		/*
		* This is our read_clock function. The host puts an tsc timestamp each time
		* it updates a new time. Without the tsc adjustment, we can have a situation
		* in which a vcpu starts to run earlier (smaller system_time), but probes
		* time later (compared to another vcpu), leading to backwards time
		*/
		static cycle_t kvm_clock_read(void)
		{
		u64 last_tsc, now;
		int cpu;
		struct pvclock_vcpu_time_info *src;
		cycle_t ret;

		preempt_disable();
		cpu = smp_processor_id();

		last_tsc = get_clock(cpu, tsc_timestamp);
		now = get_clock(cpu, system_time);

		now += kvm_get_delta(last_tsc);
		preempt_enable();

		return now;
		src = &get_cpu_var(hv_clock);
		ret = pvclock_clocksource_read(src);
		put_cpu_var(hv_clock);
		return ret;
		}

		static struct clocksource kvm_clock = {
		.name = "kvm-clock",
		.read = kvm_clock_read,
		@@ -123,13 +88,14 @@ static struct clocksource kvm_clock = {
		.flags = CLOCK_SOURCE_IS_CONTINUOUS,
		};

		static int kvm_register_clock(void)
		static int kvm_register_clock(char *txt)
		{
		int cpu = smp_processor_id();
		int low, high;
		low = (int)__pa(&per_cpu(hv_clock, cpu)) \| 1;
		high = ((u64)__pa(&per_cpu(hv_clock, cpu)) >> 32);

		printk(KERN_INFO "kvm-clock: cpu %d, msr %x:%x, %s\n",
		cpu, high, low, txt);
		return native_write_msr_safe(MSR_KVM_SYSTEM_TIME, low, high);
		}

		@@ -140,12 +106,20 @@ 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());
		WARN_ON(kvm_register_clock("secondary cpu clock"));
		/* ok, done with our trickery, call native */
		setup_secondary_APIC_clock();
		}
		#endif

		#ifdef CONFIG_SMP
		void __init kvm_smp_prepare_boot_cpu(void)
		{
		WARN_ON(kvm_register_clock("primary cpu clock"));
		native_smp_prepare_boot_cpu();
		}
		#endif

		/*
		* After the clock is registered, the host will keep writing to the
		* registered memory location. If the guest happens to shutdown, this memory
		@@ -174,13 +148,16 @@ void __init kvmclock_init(void)
		return;

		if (kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) {
		if (kvm_register_clock())
		if (kvm_register_clock("boot clock"))
		return;
		pv_time_ops.get_wallclock = kvm_get_wallclock;
		pv_time_ops.set_wallclock = kvm_set_wallclock;
		pv_time_ops.sched_clock = kvm_clock_read;
		#ifdef CONFIG_X86_LOCAL_APIC
		pv_apic_ops.setup_secondary_clock = kvm_setup_secondary_clock;
		#endif
		#ifdef CONFIG_SMP
		smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
		#endif
		machine_ops.shutdown = kvm_shutdown;
		#ifdef CONFIG_KEXEC

arch/x86/kernel/pvclock.c

0 → 100644

+141 −0

Original line number	Diff line number	Diff line
		/* paravirtual clock -- common code used by kvm/xen

		This program is free software; you can redistribute it and/or modify
		it under the terms of the GNU General Public License as published by
		the Free Software Foundation; either version 2 of the License, or
		(at your option) any later version.

		This program is distributed in the hope that it will be useful,
		but WITHOUT ANY WARRANTY; without even the implied warranty of
		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		GNU General Public License for more details.

		You should have received a copy of the GNU General Public License
		along with this program; if not, write to the Free Software
		Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
		*/

		#include <linux/kernel.h>
		#include <linux/percpu.h>
		#include <asm/pvclock.h>

		/*
		* These are perodically updated
		* xen: magic shared_info page
		* kvm: gpa registered via msr
		* and then copied here.
		*/
		struct pvclock_shadow_time {
		u64 tsc_timestamp; /* TSC at last update of time vals. */
		u64 system_timestamp; /* Time, in nanosecs, since boot. */
		u32 tsc_to_nsec_mul;
		int tsc_shift;
		u32 version;
		};

		/*
		* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
		* yielding a 64-bit result.
		*/
		static inline u64 scale_delta(u64 delta, u32 mul_frac, int shift)
		{
		u64 product;
		#ifdef __i386__
		u32 tmp1, tmp2;
		#endif

		if (shift < 0)
		delta >>= -shift;
		else
		delta <<= shift;

		#ifdef __i386__
		__asm__ (
		"mul %5 ; "
		"mov %4,%%eax ; "
		"mov %%edx,%4 ; "
		"mul %5 ; "
		"xor %5,%5 ; "
		"add %4,%%eax ; "
		"adc %5,%%edx ; "
		: "=A" (product), "=r" (tmp1), "=r" (tmp2)
		: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
		#elif __x86_64__
		__asm__ (
		"mul %%rdx ; shrd $32,%%rdx,%%rax"
		: "=a" (product) : "0" (delta), "d" ((u64)mul_frac) );
		#else
		#error implement me!
		#endif

		return product;
		}

		static u64 pvclock_get_nsec_offset(struct pvclock_shadow_time *shadow)
		{
		u64 delta = native_read_tsc() - shadow->tsc_timestamp;
		return scale_delta(delta, shadow->tsc_to_nsec_mul, shadow->tsc_shift);
		}

		/*
		* Reads a consistent set of time-base values from hypervisor,
		* into a shadow data area.
		*/
		static unsigned pvclock_get_time_values(struct pvclock_shadow_time *dst,
		struct pvclock_vcpu_time_info *src)
		{
		do {
		dst->version = src->version;
		rmb(); /* fetch version before data */
		dst->tsc_timestamp = src->tsc_timestamp;
		dst->system_timestamp = src->system_time;
		dst->tsc_to_nsec_mul = src->tsc_to_system_mul;
		dst->tsc_shift = src->tsc_shift;
		rmb(); /* test version after fetching data */
		} while ((src->version & 1) \|\| (dst->version != src->version));

		return dst->version;
		}

		cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
		{
		struct pvclock_shadow_time shadow;
		unsigned version;
		cycle_t ret, offset;

		do {
		version = pvclock_get_time_values(&shadow, src);
		barrier();
		offset = pvclock_get_nsec_offset(&shadow);
		ret = shadow.system_timestamp + offset;
		barrier();
		} while (version != src->version);

		return ret;
		}

		void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
		struct pvclock_vcpu_time_info *vcpu_time,
		struct timespec *ts)
		{
		u32 version;
		u64 delta;
		struct timespec now;

		/* get wallclock at system boot */
		do {
		version = wall_clock->version;
		rmb(); /* fetch version before time */
		now.tv_sec = wall_clock->sec;
		now.tv_nsec = wall_clock->nsec;
		rmb(); /* fetch time before checking version */
		} while ((wall_clock->version & 1) \|\| (version != wall_clock->version));

		delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */
		delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;

		now.tv_nsec = do_div(delta, NSEC_PER_SEC);
		now.tv_sec = delta;

		set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
		}

arch/x86/kvm/i8254.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -200,10 +200,13 @@ int __pit_timer_fn(struct kvm_kpit_state *ps)

		atomic_inc(&pt->pending);
		smp_mb__after_atomic_inc();
		if (vcpu0 && waitqueue_active(&vcpu0->wq)) {
		if (vcpu0) {
		set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
		if (waitqueue_active(&vcpu0->wq)) {
		vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE;
		wake_up_interruptible(&vcpu0->wq);
		}
		}

		pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
		pt->scheduled = ktime_to_ns(pt->timer.expires);

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