On Wed, Oct 21, 2015 at 04:32:17PM +0800, Cao jin wrote: > Hello Michael > > On 10/13/2015 09:10 PM, Michael S. Tsirkin wrote: > >On Tue, Oct 13, 2015 at 07:54:07PM +0800, Cao jin wrote: > >> > >> > >>On 10/13/2015 04:49 PM, Michael S. Tsirkin wrote: > >>>On Tue, Oct 13, 2015 at 04:41:33PM +0800, Cao jin wrote: > >>>>Support PCI-e device hot-add multi-function via device_add, just ensure > >>>>add the function 0 is added last. While allow user to roll back in the > >>>>middle via device_del, in case user regret. > >>> > >>>This patch doesn't seem to account of AIR though. > >>> > >> > >>Yes, but the AIR function seems never be used(nobody calls the function > >>pcie_ari_init()), so I am a little confused about should it be consindered? > > > >Yes please - we'll likely use that in the future. Pls add an API > >that takes ari into account. > > > after analysed the code and read the spec, but still a little confused about > "add an API that takes ari into account". what is new API for? Could you > give a detailed description?
You are assuming PCI_FUNC == 0 means function 9. But the real rule is: for an express device associated with an upstream port, it's devfn == 0. For any other device (non express or not connected to an upstream port) - PCI_FUNC == 0. I think a reasonable API could be e.g. bool pci_is_function_0() with a comment explaining the issues. > AFAICT now, taking ari into account will affect the "addr" property of PCI > device(maybe also need a new prop of "ari=on" to enable ari). > > >>>>changelog: > >>>>1. Flag device as unexposed when func 0 doesn`t exist, via return 0xFF > >>>> in case of gratuitous pci bus scan. > >>>>2. Since device is unexposed to guest, can remove function individually, > >>>> without interaction with the guest. > >>>> > >>>>Cao jin (2): > >>>> enable multi-function hot-add > >>>> remove function during multi-function hot-add > >>>> > >>>> hw/pci/pci.c | 10 ++++++++++ > >>>> hw/pci/pci_host.c | 6 +++++- > >>>> hw/pci/pcie.c | 38 +++++++++++++++++++++++++------------- > >>>> 3 files changed, 40 insertions(+), 14 deletions(-) > >>>> > >>>>-- > >>>>2.1.0 > >>>. > >>> > >> > >>-- > >>Yours Sincerely, > >> > >>Cao Jin > >. > > > > -- > Yours Sincerely, > > Cao Jin
