David Howells <dhowe...@redhat.com> writes: > Rusty Russell <ru...@rustcorp.com.au> wrote: > >> Macro still isn't usable, because userspace can't know whether it's the >> new or old. >> >> We need to either remove it from UAPI, or rename it to >> VIRTIO_PCI_CONFIG_OFF. > > Surely, if userspace is using it as is, you can't remove it, rename it or > alter it?
The point of the patch is that it's unusable: #define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20) ie. it's accessing a member of the kernel's virtio_pci_dev structure. In theory, userspace could have a structure with the same field and be using it now, but that's unlikely (qemu certainly doesn't). No harm no foul. In theory it's actually a useful macro, so we could expose it to userspace, but we'd need to have a new name so userspace can #ifdef for older headers... Hope that clarifies, Rusty. -- 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
