> From: Michael S. Tsirkin <mst@xxxxxxxxxx> > Sent: Tuesday, July 26, 2022 3:52 PM > > On Tue, Jul 26, 2022 at 03:56:32PM +0000, Parav Pandit wrote: > > > > > From: Zhu, Lingshan <lingshan.zhu@xxxxxxxxx> > > > Sent: Tuesday, July 12, 2022 11:46 PM > > > > When the user space which invokes netlink commands, detects that > > > > _MQ > > > is not supported, hence it takes max_queue_pair = 1 by itself. > > > I think the kernel module have all necessary information and it is > > > the only one which have precise information of a device, so it > > > should answer precisely than let the user space guess. The kernel > > > module should be reliable than stay silent, leave the question to the user > space tool. > > Kernel is reliable. It doesn’t expose a config space field if the field doesn’t exist > regardless of field should have default or no default. > > User space should not guess either. User space gets to see if _MQ present/not > present. If _MQ present than get reliable data from kernel. > > If _MQ not present, it means this device has one VQ pair. > > Yes that's fine. And if we just didn't return anything without MQ that would be > fine. But IIUC netlink reports the # of pairs regardless, it just puts 0 there. I read it differently at [1] which checks for the MQ feature bit. [1] https://elixir.bootlin.com/linux/latest/source/drivers/vdpa/vdpa.c#L825 > > -- > MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
