diff options
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 84 |
1 files changed, 62 insertions, 22 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 246852397e3..0014ee99dc7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -100,11 +100,14 @@ EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; +struct page *bad_page; +static pfn_t bad_pfn; + static struct page *hwpoison_page; static pfn_t hwpoison_pfn; -struct page *fault_page; -pfn_t fault_pfn; +static struct page *fault_page; +static pfn_t fault_pfn; inline int kvm_is_mmio_pfn(pfn_t pfn) { @@ -236,6 +239,9 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) } vcpu->run = page_address(page); + kvm_vcpu_set_in_spin_loop(vcpu, false); + kvm_vcpu_set_dy_eligible(vcpu, false); + r = kvm_arch_vcpu_init(vcpu); if (r < 0) goto fail_free_run; @@ -332,8 +338,7 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, * count is also read inside the mmu_lock critical section. */ kvm->mmu_notifier_count++; - for (; start < end; start += PAGE_SIZE) - need_tlb_flush |= kvm_unmap_hva(kvm, start); + need_tlb_flush = kvm_unmap_hva_range(kvm, start, end); need_tlb_flush |= kvm->tlbs_dirty; /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) @@ -950,12 +955,6 @@ int is_hwpoison_pfn(pfn_t pfn) } EXPORT_SYMBOL_GPL(is_hwpoison_pfn); -int is_fault_pfn(pfn_t pfn) -{ - return pfn == fault_pfn; -} -EXPORT_SYMBOL_GPL(is_fault_pfn); - int is_noslot_pfn(pfn_t pfn) { return pfn == bad_pfn; @@ -1039,11 +1038,12 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); -static pfn_t get_fault_pfn(void) +pfn_t get_fault_pfn(void) { get_page(fault_page); return fault_pfn; } +EXPORT_SYMBOL_GPL(get_fault_pfn); int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int write, struct page **page) @@ -1065,8 +1065,8 @@ static inline int check_user_page_hwpoison(unsigned long addr) return rc == -EHWPOISON; } -static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, - bool *async, bool write_fault, bool *writable) +static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, + bool write_fault, bool *writable) { struct page *page[1]; int npages = 0; @@ -1146,9 +1146,9 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, return pfn; } -pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr) +pfn_t hva_to_pfn_atomic(unsigned long addr) { - return hva_to_pfn(kvm, addr, true, NULL, true, NULL); + return hva_to_pfn(addr, true, NULL, true, NULL); } EXPORT_SYMBOL_GPL(hva_to_pfn_atomic); @@ -1166,7 +1166,7 @@ static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async, return page_to_pfn(bad_page); } - return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable); + return hva_to_pfn(addr, atomic, async, write_fault, writable); } pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn) @@ -1195,11 +1195,10 @@ pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); -pfn_t gfn_to_pfn_memslot(struct kvm *kvm, - struct kvm_memory_slot *slot, gfn_t gfn) +pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { unsigned long addr = gfn_to_hva_memslot(slot, gfn); - return hva_to_pfn(kvm, addr, false, NULL, true, NULL); + return hva_to_pfn(addr, false, NULL, true, NULL); } int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages, @@ -1580,6 +1579,43 @@ bool kvm_vcpu_yield_to(struct kvm_vcpu *target) } EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to); +#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT +/* + * Helper that checks whether a VCPU is eligible for directed yield. + * Most eligible candidate to yield is decided by following heuristics: + * + * (a) VCPU which has not done pl-exit or cpu relax intercepted recently + * (preempted lock holder), indicated by @in_spin_loop. + * Set at the beiginning and cleared at the end of interception/PLE handler. + * + * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get + * chance last time (mostly it has become eligible now since we have probably + * yielded to lockholder in last iteration. This is done by toggling + * @dy_eligible each time a VCPU checked for eligibility.) + * + * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding + * to preempted lock-holder could result in wrong VCPU selection and CPU + * burning. Giving priority for a potential lock-holder increases lock + * progress. + * + * Since algorithm is based on heuristics, accessing another VCPU data without + * locking does not harm. It may result in trying to yield to same VCPU, fail + * and continue with next VCPU and so on. + */ +bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) +{ + bool eligible; + + eligible = !vcpu->spin_loop.in_spin_loop || + (vcpu->spin_loop.in_spin_loop && + vcpu->spin_loop.dy_eligible); + + if (vcpu->spin_loop.in_spin_loop) + kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible); + + return eligible; +} +#endif void kvm_vcpu_on_spin(struct kvm_vcpu *me) { struct kvm *kvm = me->kvm; @@ -1589,6 +1625,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) int pass; int i; + kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not * currently running, because it got preempted by something @@ -1607,6 +1644,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) continue; if (waitqueue_active(&vcpu->wq)) continue; + if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) + continue; if (kvm_vcpu_yield_to(vcpu)) { kvm->last_boosted_vcpu = i; yielded = 1; @@ -1614,6 +1653,10 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) } } } + kvm_vcpu_set_in_spin_loop(me, false); + + /* Ensure vcpu is not eligible during next spinloop */ + kvm_vcpu_set_dy_eligible(me, false); } EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin); @@ -2697,9 +2740,6 @@ static struct syscore_ops kvm_syscore_ops = { .resume = kvm_resume, }; -struct page *bad_page; -pfn_t bad_pfn; - static inline struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn) { |