On Thu, Nov 06, 2008 at 09:53:08AM -0800, Greg KH wrote: > On Thu, Nov 06, 2008 at 10:47:41AM -0700, Matthew Wilcox wrote: > > On Thu, Nov 06, 2008 at 08:49:19AM -0800, Greg KH wrote: > > > On Thu, Nov 06, 2008 at 08:41:53AM -0800, H L wrote: > > > > I have not modified any existing drivers, but instead I threw together > > > > a bare-bones module enabling me to make a call to pci_iov_register() > > > > and then poke at an SR-IOV adapter's /sys entries for which no driver > > > > was loaded. > > > > > > > > It appears from my perusal thus far that drivers using these new > > > > SR-IOV patches will require modification; i.e. the driver associated > > > > with the Physical Function (PF) will be required to make the > > > > pci_iov_register() call along with the requisite notify() function. > > > > Essentially this suggests to me a model for the PF driver to perform > > > > any "global actions" or setup on behalf of VFs before enabling them > > > > after which VF drivers could be associated. > > > > > > Where would the VF drivers have to be associated? On the "pci_dev" > > > level or on a higher one? > > > > > > Will all drivers that want to bind to a "VF" device need to be > > > rewritten? > > > > The current model being implemented by my colleagues has separate > > drivers for the PF (aka native) and VF devices. I don't personally > > believe this is the correct path, but I'm reserving judgement until I > > see some code. > > Hm, I would like to see that code before we can properly evaluate this > interface. Especially as they are all tightly tied together. > > > I don't think we really know what the One True Usage model is for VF > > devices. Chris Wright has some ideas, I have some ideas and Yu Zhao has > > some ideas. I bet there's other people who have other ideas too. > > I'd love to hear those ideas. > > Rumor has it, there is some Xen code floating around to support this > already, is that true? Xen patches were posted to xen-devel by Yu Zhao on the 29th of September [1]. Unfortunately the only responses that I can find are a) that the patches were mangled and b) they seem to include changes (by others) that have been merged into Linux. I have confirmed that both of these concerns are valid. I have not yet examined the difference, if any, in the approach taken by Yu to SR-IOV in Linux and Xen. Unfortunately comparison is less than trivial due to the gaping gap in kernel versions between Linux-Xen (2.6.18.8) and Linux itself. One approach that I was considering in order to familiarise myself with the code was to backport the v6 Linux patches (this thread) to Linux-Xen. I made a start on that, but again due to kernel version differences it is non-trivial. [1] http://lists.xensource.com/archives/html/xen-devel/2008-09/msg00923.html -- Simon Horman VA Linux Systems Japan K.K., Sydney, Australia Satellite Office H: www.vergenet.net/~horms/ W: www.valinux.co.jp/en -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
