On Wed, 2013-12-18 at 17:07 -0800, Greg Kroah-Hartman wrote: > On Tue, Dec 03, 2013 at 12:34:46PM +0000, Kim Phillips wrote: > > VFIO supports pass-through of devices to user space - for sake > > of illustration, say a PCI e1000 device: > > > > - the e1000 is first unbound from the PCI e1000 driver via sysfs > > - the vfio-pci driver is told via new_id that it now handles e1000 devices > > - the e1000 is explicitly bound to vfio-pci through sysfs > > > > However, now we have two drivers in the system that both handle e1000 > > devices. A hotplug event could then occur and it is ambiguous as to which > > driver will claim the device. The desired semantics is that vfio-pci is > > only bound to devices by explicit request in sysfs. This patch makes this > > possible by introducing a sysfs_bind_only flag in struct device_driver. > > Why deal with this at all and not just deal with the "bind" sysfs file > instead? That way no driver core logic needs to be changed at all, and > your userspace tools know _exactly_ which device is being bound to the > new device. > > Don't mess with the "new_id" file for stuff like this, as you point out, > it's "tricky"... As discussed before, "bind" does not bypass the ID checks, and thus it does not work without either "new_id" or a wildcard match. Or are you proposing changing "bind" so that it does bypass the ID checks? Or perhaps a new "force_bind" file that does? -Scott -- 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
