Re: [PATCH libvirt v1 3/6] conf: fix ZPCI address auto-generation on s390

On 6/3/20 12:58 PM, Andrea Bolognani wrote: > On Thu, 2020-04-09 at 12:31 +0200, Shalini Chellathurai Saroja wrote: > > +++ b/tests/qemuxml2xmloutdata/hostdev-vfio-zpci-multidomain-many.xml > > @@ -39,7 +39,7 @@ > > <address domain='0x0003' bus='0x00' slot='0x00' function='0x0'/> > > </source> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'> > > - <zpci uid='0x0001' fid='0x00000001'/> > > + <zpci uid='0x0001' fid='0x00000000'/> > > </address> > > </hostdev> > > <hostdev mode='subsystem' type='pci' managed='no'> > > @@ -48,7 +48,7 @@ > > <address domain='0x0004' bus='0x00' slot='0x00' function='0x0'/> > > </source> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'> > > - <zpci uid='0x0002' fid='0x00000002'/> > > + <zpci uid='0x0002' fid='0x00000001'/> > > </address> > > </hostdev> > > <hostdev mode='subsystem' type='pci' managed='no'> > > @@ -57,7 +57,7 @@ > > <address domain='0x0005' bus='0x00' slot='0x00' function='0x0'/> > > </source> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'> > > - <zpci uid='0x0053' fid='0x00000000'/> > > + <zpci uid='0x0053' fid='0x00000002'/> > > I'm not entirely clear on why these generated ZPCI addresses would > change. Can you explain that to me? Sure:-). It changes in this version because at first the user specified addresses are reserved and then the addresses which are not specified by the user are assigned and reserved. In the current master code, as uid and fid are correlated, both uid and fid are reserved, when either one of them is specified by the user. So for the pci device with uid = '0x0053', the code assumes that user has specified fid as 0 (which is not true) and reserves fid as 0.