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Commit 919c0d14 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm 

* 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
  KVM: Remove now unused structs from kvm_para.h
  x86: KVM guest: Use the paravirt clocksource structs and functions
  KVM: Make kvm host use the paravirt clocksource structs
  x86: Make xen use the paravirt clocksource structs and functions
  x86: Add structs and functions for paravirt clocksource
  KVM: VMX: Fix host msr corruption with preemption enabled
  KVM: ioapic: fix lost interrupt when changing a device's irq
  KVM: MMU: Fix oops on guest userspace access to guest pagetable
  KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend)
  KVM: MMU: Fix rmap_write_protect() hugepage iteration bug
  KVM: close timer injection race window in __vcpu_run
  KVM: Fix race between timer migration and vcpu migration
parents de08341a 6b1ed908

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);