Commit 5e58cfe4 authored by Rusty Russell's avatar Rusty Russell Committed by Avi Kivity
Browse files

KVM: Fix unlikely kvm_create vs decache_vcpus_on_cpu race 



We add the kvm to the vm_list before initializing the vcpu mutexes,
which can be mutex_trylock()'ed by decache_vcpus_on_cpu().

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent b0fcd903

drivers/kvm/kvm_main.c

+3 −3
Original line number Diff line number Diff line
@@ -297,9 +297,6 @@ static struct kvm *kvm_create_vm(void) 
	kvm_io_bus_init(&kvm->pio_bus);

	spin_lock_init(&kvm->lock);

	INIT_LIST_HEAD(&kvm->active_mmu_pages);

	spin_lock(&kvm_lock);

	list_add(&kvm->vm_list, &vm_list);

	spin_unlock(&kvm_lock);

	kvm_io_bus_init(&kvm->mmio_bus);

	for (i = 0; i < KVM_MAX_VCPUS; ++i) {

		struct kvm_vcpu *vcpu = &kvm->vcpus[i];
@@ -309,6 +306,9 @@ static struct kvm *kvm_create_vm(void) 
		vcpu->kvm = kvm;

		vcpu->mmu.root_hpa = INVALID_PAGE;

	}

	spin_lock(&kvm_lock);

	list_add(&kvm->vm_list, &vm_list);

	spin_unlock(&kvm_lock);

	return kvm;

}