On Tue, Aug 09, 2016 at 03:16:26PM +0200, Paolo Bonzini wrote: > > > On 09/08/2016 14:55, Christoffer Dall wrote: > > On Tue, Aug 09, 2016 at 02:37:43PM +0200, Paolo Bonzini wrote: > >> > >> > >> On 09/08/2016 14:20, Christoffer Dall wrote: > >>> KVM devices were manipulating list data structures without any form of > >>> synchronization, and some implementations of the create operations also > >>> suffered from a lack of synchronization. > >>> > >>> Now when we've split the xics create operation into create and init, we > >>> can hold the kvm->lock mutex while calling the create operation and when > >>> manipulating the devices list. > >>> > >>> The error path in the generic code gets slightly ugly because we have to > >>> take the mutex again and delete the device from the list, but holding > >>> the mutex during anon_inode_getfd or releasing/locking the mutex in the > >>> common non-error path seemed wrong. > >>> > >>> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> > >> > >> Very nice (and small), but please add a comment to the create member in > >> kvm_device_ops. > > > > Like this?: > > > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > > index d3c9b82..9c28b4d 100644 > > --- a/include/linux/kvm_host.h > > +++ b/include/linux/kvm_host.h > > @@ -1113,6 +1113,12 @@ struct kvm_device { > > /* create, destroy, and name are mandatory */ > > struct kvm_device_ops { > > const char *name; > > + > > + /* > > + * create is called holding kvm->lock and any operations not suitable > > + * to do while holding the lock should be deferred to init (see > > + * below). > > + */ > > int (*create)(struct kvm_device *dev, u32 type); > > > > /* > > > > That's okay, series > > Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Thanks, I'll send a v2. Will you just apply the patches to kvm/master or would you like me to include it in my pull request for -rc2 ? Also, do you want to wait for a tested-by from the other arch maintainers? -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html