Hi Alex, Thanks very much for your time and answer! Best Regards Nan Xiao On Fri, Sep 11, 2015 at 8:18 AM, Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > On Fri, 2015-09-11 at 07:58 +0800, Nan Xiao wrote: >> Hi Alex, >> >> Thanks very much for your response! so for assigning PCI device in QEMU. >> The following method is deprecated: >> >> qemu-system-x86_64 ... -device pci-assign,host=0000:21:00.1 >> >> I should use this one instead: >> >> qemu-system-x86_64 ... -device vfio-pci,host=0000:21:00.1 >> >> right? > > Yes, and the device needs to be bound to the vfio_pci driver in the host > rather than pci-stub (and you may or may not need to care about IOMMU > groups[1]). Thanks, > > Alex > > [1] http://vfio.blogspot.com/2014/08/iommu-groups-inside-and-out.html > >> On Thu, Sep 10, 2015 at 11:08 PM, Alex Williamson >> <alex.williamson@xxxxxxxxxx> wrote: >> > On Thu, 2015-09-10 at 18:22 +0800, Nan Xiao wrote: >> >> Hi all, >> >> >> >> When building kernel, it prompts "CONFIG_KVM_DEVICE_ASSIGNMENT" is "deprecated". >> >> But it is still used in kernel code. E.g.: >> >> "kvm_vm_ioctl_check_extension" function: >> >> { >> >> ... >> >> #ifdef CONFIG_KVM_DEVICE_ASSIGNMENT >> >> case KVM_CAP_ASSIGN_DEV_IRQ: >> >> case KVM_CAP_PCI_2_3: >> >> #endif >> >> r = 1; >> >> break; >> >> ... >> >> #ifdef CONFIG_KVM_DEVICE_ASSIGNMENT >> >> case KVM_CAP_IOMMU: >> >> r = iommu_present(&pci_bus_type); >> >> break; >> >> #endif >> >> ... >> >> } >> >> >> >> If not configure this option, the following code will execute failed: >> >> >> >> ret = ioctl(dev, KVM_CHECK_EXTENSION, KVM_CAP_IOMMU); >> >> >> >> So does it mean to use KVM assigned device feature, the >> >> "CONFIG_KVM_DEVICE_ASSIGNMENT" >> >> is not "deprecated"? >> > >> > Legacy KVM device assignment is deprecated, it is fully replaced by >> > VFIO-based device assignment. The intention is to deprecate legacy KVM >> > device assignment now, so all users can transition away from it and at >> > some point remove it from the kernel. When using QEMU and libvirt, the >> > default is already to use VFIO instead of legacy KVM device assignment. >> > Thanks, >> > >> > Alex >> > >> > >> > >> -- >> 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 > > > -- 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
