diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index f5f2c6bf5856..8355398f0bb6 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1419,16 +1419,20 @@ static void resize_hpt_pivot(struct kvm_resize_hpt *resize) static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize) { - BUG_ON(kvm->arch.resize_hpt != resize); + if (WARN_ON(!mutex_is_locked(&kvm->lock))) + return; if (!resize) return; - if (resize->hpt.virt) - kvmppc_free_hpt(&resize->hpt); + if (resize->error != -EBUSY) { + if (resize->hpt.virt) + kvmppc_free_hpt(&resize->hpt); + kfree(resize); + } - kvm->arch.resize_hpt = NULL; - kfree(resize); + if (kvm->arch.resize_hpt == resize) + kvm->arch.resize_hpt = NULL; } static void resize_hpt_prepare_work(struct work_struct *work) @@ -1437,26 +1441,42 @@ static void resize_hpt_prepare_work(struct work_struct *work) struct kvm_resize_hpt, work); struct kvm *kvm = resize->kvm; - int err; + int err = 0; if (WARN_ON(resize->error != -EBUSY)) return; - resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n", - resize->order); - - err = resize_hpt_allocate(resize); - - /* We have strict assumption about -EBUSY - * when preparing for HPT resize. - */ - if (WARN_ON(err == -EBUSY)) - err = -EINPROGRESS; - mutex_lock(&kvm->lock); + /* Request is still current? */ + if (kvm->arch.resize_hpt == resize) { + /* We may request large allocations here: + * do not sleep with kvm->lock held for a while. + */ + mutex_unlock(&kvm->lock); + + resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n", + resize->order); + + err = resize_hpt_allocate(resize); + + /* We have strict assumption about -EBUSY + * when preparing for HPT resize. + */ + if (WARN_ON(err == -EBUSY)) + err = -EINPROGRESS; + + mutex_lock(&kvm->lock); + /* It is possible that kvm->arch.resize_hpt != resize + * after we grab kvm->lock again. + */ + } + resize->error = err; + if (kvm->arch.resize_hpt != resize) + resize_hpt_release(kvm, resize); + mutex_unlock(&kvm->lock); }