On Thu, Feb 22, 2018 at 11:04:30AM +0000, Jean-Philippe Brucker wrote: > On 21/02/18 20:12, kbuild test robot wrote: > [...] > > config: arm64-allmodconfig (attached as .config) > [...] > > aarch64-linux-gnu-ld: arch/arm64/kernel/head.o: relocation R_AARCH64_ABS32 against `_kernel_offset_le_lo32' can not be used when making a shared object > > arch/arm64/kernel/head.o: In function `kimage_vaddr': > > (.idmap.text+0x0): dangerous relocation: unsupported relocation > > Is this related? > > > arch/arm64/kernel/head.o: In function `__primary_switch': > > (.idmap.text+0x340): dangerous relocation: unsupported relocation > > (.idmap.text+0x348): dangerous relocation: unsupported relocation > > drivers/iommu/virtio-iommu.o: In function `viommu_probe': > > virtio-iommu.c:(.text+0xbdc): undefined reference to `virtio_check_driver_offered_feature' > > virtio-iommu.c:(.text+0xcfc): undefined reference to `virtio_check_driver_offered_feature' > > virtio-iommu.c:(.text+0xe10): undefined reference to `virtio_check_driver_offered_feature' > > drivers/iommu/virtio-iommu.o: In function `viommu_send_reqs_sync': > > virtio-iommu.c:(.text+0x130c): undefined reference to `virtqueue_add_sgs' > > virtio-iommu.c:(.text+0x1398): undefined reference to `virtqueue_kick' > > virtio-iommu.c:(.text+0x14d4): undefined reference to `virtqueue_get_buf' > > drivers/iommu/virtio-iommu.o: In function `virtio_iommu_drv_init': > > virtio-iommu.c:(.init.text+0x1c): undefined reference to `register_virtio_driver' > > drivers/iommu/virtio-iommu.o: In function `virtio_iommu_drv_exit': > >>> virtio-iommu.c:(.exit.text+0x14): undefined reference to `unregister_virtio_driver' > > Right. At the moment CONFIG_VIRTIO_IOMMU is a bool instead of tristate, > because the IOMMU subsystem isn't entirely ready to have IOMMU drivers > built as modules. In addition to exporting symbols it would also needs to > hold off probing endpoints behind the IOMMU until the IOMMU driver is > loaded. At the moment (I think) it gives up once userspace is reached (see > of_iommu_driver_present). > > The above report is due to VIRTIO=m and VIRTIO_IOMMU=y. To solve it we could: > > a) Allow VIRTIO_IOMMU to be built as module by exporting a dozen IOMMU > symbols. It would be a lie. The driver wouldn't be usable because of the > probe issue discussed above, but it would build. > > b) Actually make any IOMMU driver work as module. Whilst it would > certainly be a nice feature, it's a bigger problem and I don't think it > has its place in this series. > > c) Make VIRTIO_IOMMU depend on VIRTIO_MMIO=y instead of VIRTIO_MMIO, which > I think is the sanest for now (and does work), even though distro kernels > probably all have VIRTIO=m. > > I prefer doing c) now and experiment with b) once I got some time. > > Thanks, > Jean It kind of means it's a toy for now though. So fine as long as it's out of tree. -- MST _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
