From 0a4238f027e41c64afa2919440420ea56c0cae80 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 10 Oct 2023 15:09:43 -0700 Subject: [PATCH 3/3] Revert "KVM: Prevent module exit until all VMs are freed" Revert KVM's misguided attempt to "fix" a use-after-module-unload bug that was actually due to failure to flush a workqueue, not a lack of module refcounting. blah blah blah This reverts commit 405294f29faee5de8c10cb9d4a90e229c2835279 and commit commit 5f6de5cbebee925a612856fce6f9182bb3eee0db. Fixes: 405294f29fae ("KVM: Unconditionally get a ref to /dev/kvm module when creating a VM") Fixes: 5f6de5cbebee ("KVM: Prevent module exit until all VMs are freed") Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1e65a506985f..3b1b9e8dd70c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -115,8 +115,6 @@ EXPORT_SYMBOL_GPL(kvm_debugfs_dir); static const struct file_operations stat_fops_per_vm; -static struct file_operations kvm_chardev_ops; - static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT @@ -1157,9 +1155,6 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) if (!kvm) return ERR_PTR(-ENOMEM); - /* KVM is pinned via open("/dev/kvm"), the fd passed to this ioctl(). */ - __module_get(kvm_chardev_ops.owner); - KVM_MMU_LOCK_INIT(kvm); mmgrab(current->mm); kvm->mm = current->mm; @@ -1279,7 +1274,6 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) out_err_no_srcu: kvm_arch_free_vm(kvm); mmdrop(current->mm); - module_put(kvm_chardev_ops.owner); return ERR_PTR(r); } @@ -1348,7 +1342,6 @@ static void kvm_destroy_vm(struct kvm *kvm) preempt_notifier_dec(); hardware_disable_all(); mmdrop(mm); - module_put(kvm_chardev_ops.owner); } void kvm_get_kvm(struct kvm *kvm) -- 2.42.0.609.gbb76f46606-goog