Re: [libvirt] [PATCH v7 00/14] PCI passthrough support on s390

Abstract ======== The PCI representation in QEMU has been extended for S390 allowing configuration of zPCI attributes like uid (user-defined identifier) and fid (PCI function identifier). The details can be found here: https://lists.gnu.org/archive/html/qemu-devel/2016-06/msg07262.html To support the new zPCI feature of the S390 platform, a new element of PCI address is introduced. It has two optional attributes, @uid and @fid. For example: <hostdev mode='subsystem' type='pci'> <driver name='vfio'/> <source> <address domain='0x0001' bus='0x00' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'> <zpci uid='0x0003' fid='0x00000027'/> </address> </hostdev> If they are defined by the user, unique values within the guest domain must be used. If they are not specified and the architecture requires them, they are automatically generated with non-conflicting values. zPCI address as an extension of the PCI address are stored in a new structure 'virZPCIDeviceAddress' which is a member of common PCI Address structure. Additionally, two hashtables are used for assignment and reservation of zPCI uid/fid. In support of extending the PCI address, a new PCI address extension flag is introduced. This extension flag allows is not only dedicated for the S390 platform but also other architectures needing certain extensions to PCI address space.