This fixes virtio on Xen guests as well as on any other platform that uses virtio_pci on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches, everything works. This should be safe on all platforms that I'm aware of. That doesn't mean that there isn't anything that I missed. Applies to net-next. Changes from v4: - Rebased onto net-next. - Dropped the sg end mark changes from virtio_net, as that issue is solved differently in net-next. - virtio_pci does not use the DMA API on powerpc, for reasons that are explained in a detailed comment in virtio_ring. Changes from v3: - virtio_pci only asks virtio_ring to use the DMA API if !PCI_DMA_BUS_IS_PHYS. - Reduce tools/virtio breakage. It's now merely as broken as before instead of being even more broken. - Drop the sg_next changes -- Rusty's version is better. Changes from v2: - Reordered patches. - Fixed a virtio_net OOPS. Changes from v1: - Using the DMA API is optional now. It would be nice to improve the DMA API to the point that it could be used unconditionally, but s390 proves that we're not there yet. - Includes patch 4, which fixes DMA debugging warnings from virtio_net. Andy Lutomirski (3): virtio_ring: Support DMA APIs if requested virtio_pci: Use the DMA API for virtqueues when possible virtio_net: Stop doing DMA from the stack drivers/lguest/lguest_device.c | 3 +- drivers/misc/mic/card/mic_virtio.c | 2 +- drivers/net/virtio_net.c | 53 ++++++--- drivers/remoteproc/remoteproc_virtio.c | 4 +- drivers/s390/kvm/kvm_virtio.c | 2 +- drivers/s390/kvm/virtio_ccw.c | 4 +- drivers/virtio/virtio_mmio.c | 5 +- drivers/virtio/virtio_pci.c | 91 ++++++++++++++-- drivers/virtio/virtio_ring.c | 194 +++++++++++++++++++++++++++------ include/linux/virtio_ring.h | 1 + tools/virtio/linux/dma-mapping.h | 17 +++ tools/virtio/linux/virtio.h | 1 + tools/virtio/virtio_test.c | 2 +- tools/virtio/vringh_test.c | 3 +- 14 files changed, 314 insertions(+), 68 deletions(-) create mode 100644 tools/virtio/linux/dma-mapping.h -- 1.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization