Re: [PATCH] KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()

2009-12-15 Thread Avi Kivity
On 12/15/2009 04:28 AM, Sheng Yang wrote: One possible order is: KVM_CREATE_IRQCHIP ioctl(took kvm-lock) - kvm_iobus_register_dev() - down_write(kvm-slots_lock). The other one is in kvm_vm_ioctl_assign_device(), which take kvm-slots_lock first, then kvm-lock. Update the comment of lock order

Re: [PATCH] KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()

2009-12-14 Thread Avi Kivity
On 12/14/2009 09:14 AM, Sheng Yang wrote: On Monday 07 December 2009 16:58:04 Sheng Yang wrote: One possible order is: KVM_CREATE_IRQCHIP ioctl(took kvm-lock) - kvm_iobus_register_dev() - down_write(kvm-slots_lock). The other one is in kvm_vm_ioctl_assign_device(), which take

Re: [PATCH] KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()

2009-12-14 Thread Marcelo Tosatti
On Mon, Dec 07, 2009 at 04:58:04PM +0800, Sheng Yang wrote: One possible order is: KVM_CREATE_IRQCHIP ioctl(took kvm-lock) - kvm_iobus_register_dev() - down_write(kvm-slots_lock). The other one is in kvm_vm_ioctl_assign_device(), which take kvm-slots_lock first, then kvm-lock. Observe

Re: [PATCH] KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()

2009-12-13 Thread Sheng Yang
On Monday 07 December 2009 16:58:04 Sheng Yang wrote: One possible order is: KVM_CREATE_IRQCHIP ioctl(took kvm-lock) - kvm_iobus_register_dev() - down_write(kvm-slots_lock). The other one is in kvm_vm_ioctl_assign_device(), which take kvm-slots_lock first, then kvm-lock. Observe it

[PATCH] KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()

2009-12-07 Thread Sheng Yang
One possible order is: KVM_CREATE_IRQCHIP ioctl(took kvm-lock) - kvm_iobus_register_dev() - down_write(kvm-slots_lock). The other one is in kvm_vm_ioctl_assign_device(), which take kvm-slots_lock first, then kvm-lock. Observe it due to kernel locking debug warnings. Signed-off-by: Sheng Yang