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Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c93
1 files changed, 67 insertions, 26 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21338bdb28ff..63a77caa59f1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -492,8 +492,8 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
492static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) 492static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
493{ 493{
494 static int version; 494 static int version;
495 struct kvm_wall_clock wc; 495 struct pvclock_wall_clock wc;
496 struct timespec wc_ts; 496 struct timespec now, sys, boot;
497 497
498 if (!wall_clock) 498 if (!wall_clock)
499 return; 499 return;
@@ -502,10 +502,19 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
502 502
503 kvm_write_guest(kvm, wall_clock, &version, sizeof(version)); 503 kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
504 504
505 wc_ts = current_kernel_time(); 505 /*
506 wc.wc_sec = wc_ts.tv_sec; 506 * The guest calculates current wall clock time by adding
507 wc.wc_nsec = wc_ts.tv_nsec; 507 * system time (updated by kvm_write_guest_time below) to the
508 wc.wc_version = version; 508 * wall clock specified here. guest system time equals host
509 * system time for us, thus we must fill in host boot time here.
510 */
511 now = current_kernel_time();
512 ktime_get_ts(&sys);
513 boot = ns_to_timespec(timespec_to_ns(&now) - timespec_to_ns(&sys));
514
515 wc.sec = boot.tv_sec;
516 wc.nsec = boot.tv_nsec;
517 wc.version = version;
509 518
510 kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc)); 519 kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));
511 520
@@ -513,6 +522,45 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
513 kvm_write_guest(kvm, wall_clock, &version, sizeof(version)); 522 kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
514} 523}
515 524
525static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
526{
527 uint32_t quotient, remainder;
528
529 /* Don't try to replace with do_div(), this one calculates
530 * "(dividend << 32) / divisor" */
531 __asm__ ( "divl %4"
532 : "=a" (quotient), "=d" (remainder)
533 : "0" (0), "1" (dividend), "r" (divisor) );
534 return quotient;
535}
536
537static void kvm_set_time_scale(uint32_t tsc_khz, struct pvclock_vcpu_time_info *hv_clock)
538{
539 uint64_t nsecs = 1000000000LL;
540 int32_t shift = 0;
541 uint64_t tps64;
542 uint32_t tps32;
543
544 tps64 = tsc_khz * 1000LL;
545 while (tps64 > nsecs*2) {
546 tps64 >>= 1;
547 shift--;
548 }
549
550 tps32 = (uint32_t)tps64;
551 while (tps32 <= (uint32_t)nsecs) {
552 tps32 <<= 1;
553 shift++;
554 }
555
556 hv_clock->tsc_shift = shift;
557 hv_clock->tsc_to_system_mul = div_frac(nsecs, tps32);
558
559 pr_debug("%s: tsc_khz %u, tsc_shift %d, tsc_mul %u\n",
560 __FUNCTION__, tsc_khz, hv_clock->tsc_shift,
561 hv_clock->tsc_to_system_mul);
562}
563
516static void kvm_write_guest_time(struct kvm_vcpu *v) 564static void kvm_write_guest_time(struct kvm_vcpu *v)
517{ 565{
518 struct timespec ts; 566 struct timespec ts;
@@ -523,6 +571,11 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
523 if ((!vcpu->time_page)) 571 if ((!vcpu->time_page))
524 return; 572 return;
525 573
574 if (unlikely(vcpu->hv_clock_tsc_khz != tsc_khz)) {
575 kvm_set_time_scale(tsc_khz, &vcpu->hv_clock);
576 vcpu->hv_clock_tsc_khz = tsc_khz;
577 }
578
526 /* Keep irq disabled to prevent changes to the clock */ 579 /* Keep irq disabled to prevent changes to the clock */
527 local_irq_save(flags); 580 local_irq_save(flags);
528 kvm_get_msr(v, MSR_IA32_TIME_STAMP_COUNTER, 581 kvm_get_msr(v, MSR_IA32_TIME_STAMP_COUNTER,
@@ -537,14 +590,14 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
537 /* 590 /*
538 * The interface expects us to write an even number signaling that the 591 * The interface expects us to write an even number signaling that the
539 * update is finished. Since the guest won't see the intermediate 592 * update is finished. Since the guest won't see the intermediate
540 * state, we just write "2" at the end 593 * state, we just increase by 2 at the end.
541 */ 594 */
542 vcpu->hv_clock.version = 2; 595 vcpu->hv_clock.version += 2;
543 596
544 shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0); 597 shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0);
545 598
546 memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock, 599 memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
547 sizeof(vcpu->hv_clock)); 600 sizeof(vcpu->hv_clock));
548 601
549 kunmap_atomic(shared_kaddr, KM_USER0); 602 kunmap_atomic(shared_kaddr, KM_USER0);
550 603
@@ -599,10 +652,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
599 /* ...but clean it before doing the actual write */ 652 /* ...but clean it before doing the actual write */
600 vcpu->arch.time_offset = data & ~(PAGE_MASK | 1); 653 vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
601 654
602 vcpu->arch.hv_clock.tsc_to_system_mul =
603 clocksource_khz2mult(tsc_khz, 22);
604 vcpu->arch.hv_clock.tsc_shift = 22;
605
606 down_read(&current->mm->mmap_sem); 655 down_read(&current->mm->mmap_sem);
607 vcpu->arch.time_page = 656 vcpu->arch.time_page =
608 gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT); 657 gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
@@ -2758,7 +2807,9 @@ again:
2758 2807
2759 if (vcpu->requests) { 2808 if (vcpu->requests) {
2760 if (test_and_clear_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests)) 2809 if (test_and_clear_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests))
2761 __kvm_migrate_apic_timer(vcpu); 2810 __kvm_migrate_timers(vcpu);
2811 if (test_and_clear_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
2812 kvm_x86_ops->tlb_flush(vcpu);
2762 if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS, 2813 if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS,
2763 &vcpu->requests)) { 2814 &vcpu->requests)) {
2764 kvm_run->exit_reason = KVM_EXIT_TPR_ACCESS; 2815 kvm_run->exit_reason = KVM_EXIT_TPR_ACCESS;
@@ -2772,6 +2823,7 @@ again:
2772 } 2823 }
2773 } 2824 }
2774 2825
2826 clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
2775 kvm_inject_pending_timer_irqs(vcpu); 2827 kvm_inject_pending_timer_irqs(vcpu);
2776 2828
2777 preempt_disable(); 2829 preempt_disable();
@@ -2781,21 +2833,13 @@ again:
2781 2833
2782 local_irq_disable(); 2834 local_irq_disable();
2783 2835
2784 if (need_resched()) { 2836 if (vcpu->requests || need_resched()) {
2785 local_irq_enable(); 2837 local_irq_enable();
2786 preempt_enable(); 2838 preempt_enable();
2787 r = 1; 2839 r = 1;
2788 goto out; 2840 goto out;
2789 } 2841 }
2790 2842
2791 if (vcpu->requests)
2792 if (test_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) {
2793 local_irq_enable();
2794 preempt_enable();
2795 r = 1;
2796 goto out;
2797 }
2798
2799 if (signal_pending(current)) { 2843 if (signal_pending(current)) {
2800 local_irq_enable(); 2844 local_irq_enable();
2801 preempt_enable(); 2845 preempt_enable();
@@ -2825,9 +2869,6 @@ again:
2825 2869
2826 kvm_guest_enter(); 2870 kvm_guest_enter();
2827 2871
2828 if (vcpu->requests)
2829 if (test_and_clear_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
2830 kvm_x86_ops->tlb_flush(vcpu);
2831 2872
2832 KVMTRACE_0D(VMENTRY, vcpu, entryexit); 2873 KVMTRACE_0D(VMENTRY, vcpu, entryexit);
2833 kvm_x86_ops->run(vcpu, kvm_run); 2874 kvm_x86_ops->run(vcpu, kvm_run);