On Mon, 2011-08-15 at 09:55 +0930, Rusty Russell wrote: > On Sun, 14 Aug 2011 16:57:32 +0300, Sasha Levin <levinsasha...@gmail.com> > wrote: > > On Sun, 2011-08-14 at 12:23 +0930, Rusty Russell wrote: > > > On Sat, 13 Aug 2011 11:51:01 +0300, Sasha Levin <levinsasha...@gmail.com> > > > wrote: > > > > The MAC of a virtio-net device is located at the first field of the > > > > device > > > > specific header. This header is located at offset 20 if the device > > > > doesn't > > > > support MSI-X or offset 24 if it does. > > > > > > Erk. This means, in general, we have to do virtio_find_single_vq or > > > config->find_vqs before we examine any config options. > > > > > > Look at virtio_blk, which has the same error. > > > > > > Solutions in order of best to worst: > > > (1) Enable MSI-X before calling device probe. This means reserving two > > > vectors in virtio_pci_probe to ensure we *can* do this, I think. > > > Michael? > > > > Do you mean reserving the vectors even before we probed the device for > > MSI-X support? Wouldn't we need 3 vectors then? (config, input, output). > > We want three, but *need* two: see vp_find_vqs(). Also, the generic > code doesn't know how many virtqueues we have on the device.
We can just pci_enable_msix() and see if we can get 2 vectors, if we can - we assume the device has msix on, right? -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
