Re: [libvirt] [question]Why libvirt bind all devices with same vendor id and device id to vfio-pci driver, and only unbind devices used by VMs to original driver?
On 10/09/2017 10:57 AM, Alex Williamson wrote: > On Mon, 9 Oct 2017 09:28:27 + > "Wuzongyong (Euler Dept)" wrote: > >> Hi, >> >> As the title says, I thought that it's a bit unreasonable and inconsistent >> to unbind devices assigned to VMs to original driver >> and leave other devices binding to vfio-pci driver. >> Why not to bind devices we need to vfio-pci driver instead of bind all >> devices with same type to vfio-pci driver? >> Or, we may can rebind devices unused with same type to original driver. > > Because that's the way the kernel's new_id interface works, any > matching device without a driver will probe the new_id driver. For a > new enough kernel and libvirt, the driver_override interface should be > used instead, which will only bind the target device. Note that all libvirt 2.3.0 and later uses driver_override rather than new_id (as long as the host kernel also supports it, which these days should almost always be the case). If you're seeing *all* unbound devices being bound to vfio-pci when only one of the devices is assigned to a guest, then either 1) you are using a host with a *very* old kernel, 2) you have modified libvirt's code to somehow force taking the old/deprecated path, or 3) there is a bug in libvirt's code. -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [question]Why libvirt bind all devices with same vendor id and device id to vfio-pci driver, and only unbind devices used by VMs to original driver?
On Mon, 9 Oct 2017 09:28:27 + "Wuzongyong (Euler Dept)" wrote: > Hi, > > As the title says, I thought that it's a bit unreasonable and inconsistent > to unbind devices assigned to VMs to original driver > and leave other devices binding to vfio-pci driver. > Why not to bind devices we need to vfio-pci driver instead of bind all > devices with same type to vfio-pci driver? > Or, we may can rebind devices unused with same type to original driver. Because that's the way the kernel's new_id interface works, any matching device without a driver will probe the new_id driver. For a new enough kernel and libvirt, the driver_override interface should be used instead, which will only bind the target device. Thanks, Alex -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
[libvirt] [question]Why libvirt bind all devices with same vendor id and device id to vfio-pci driver, and only unbind devices used by VMs to original driver?
Hi, As the title says, I thought that it's a bit unreasonable and inconsistent to unbind devices assigned to VMs to original driver and leave other devices binding to vfio-pci driver. Why not to bind devices we need to vfio-pci driver instead of bind all devices with same type to vfio-pci driver? Or, we may can rebind devices unused with same type to original driver. Thanks, Zongyong Wu -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
