Re: [libvirt] [PATCH v6 00/13] PCI passthrough support on s390

On Fri, Sep 28, 2018 at 04:46:13PM +0800, Yi Min Zhao wrote: > Abstract > ======== > The PCI representation in QEMU has recently 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> I'm not sure if this was discussed in earlier versions, but to me this use of a child element looks wrong. What we're effectively saying is that s390 has a different addressing scheme. It happens to share some fields with the current PCI addressing scheme, but it is none the less a distinct scheme. IOW, I think it should be <address type='zpci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' uid='0x0003' fid='0x00000027'/> Of course internally we can still share much logic for assigning the addreses between "pci" and "zpci". Regards, Daniel