Enhanced virtualization protection technology may require the use of bounce buffers for I/O. While support for this was built into the virtio core, virtio-ccw wasn't changed accordingly. Thus what needs to be done to bring virtio-ccw up to speed with respect to this is: * use some 'new' common virtio stuff * make sure that virtio-ccw specific stuff uses shared memory when talking to the hypervisor (except communication blocks like ORB, these are handled by the hypervisor) * make sure the DMA API does what is necessary to talk through shared memory if we are a protected virtualization guest. * make sure the common IO layer plays along as well (airqs, sense). The series is structured in incremental fashion: some of the changes are overridden by following patches. The main reason why is that this is how I developed. But I think it ain't bad for the didactic and we are a bit more flexible with regards to throwing out some of the stuff in the end. Important notes: * This is an early (WIP) RFC that does not add any function to the kernel at his stage, as the ultravisor interactions are left out. The purpose is getting some early feedback ASAP. * In future these patches will depend on some code interacting with the ultravisor (WIP by Vasily and Janosch). * The s390 names are by no means final, and are not properly explained. Should not hamper understanding too much. If it does please ask. * The existing naming in the common infrastructure (kernel internal interfaces) is pretty much based on the AMD SEV terminology. Thus the names aren't always perfect. There might be merit to changing these names to more abstract ones. I did not put much thought into that at the current stage. Testing: Please use iommu_platform=on for any virtio devices you are going to test this code with (so virtio actually uses the DMA API). Looking forward to your review or any other type of input. Halil Pasic (12): virtio/s390: use vring_create_virtqueue virtio/s390: DMA support for virtio-ccw s390/mm: force swiotlb for protected virtualization s390/cio: introduce cio DMA pool s390/cio: add protected virtualization support to cio s390/airq: use DMA memory for adapter interrupts virtio/s390: use DMA memory for ccw I/O virtio/s390: add indirection to indicators access virtio/s390: use DMA memory for notifiers virtio/s390: consolidate DMA allocations virtio/s390: use the cio DMA pool virtio/s390: make airq summary indicators DMA arch/s390/Kconfig | 5 + arch/s390/include/asm/Kbuild | 1 - arch/s390/include/asm/airq.h | 2 + arch/s390/include/asm/cio.h | 4 + arch/s390/include/asm/dma-mapping.h | 13 ++ arch/s390/include/asm/mem_encrypt.h | 18 +++ arch/s390/mm/init.c | 44 +++++ drivers/s390/cio/airq.c | 18 ++- drivers/s390/cio/ccwreq.c | 8 +- drivers/s390/cio/css.c | 63 ++++++++ drivers/s390/cio/device.c | 46 ++++-- drivers/s390/cio/device_fsm.c | 40 ++--- drivers/s390/cio/device_id.c | 18 +-- drivers/s390/cio/device_ops.c | 4 +- drivers/s390/cio/device_pgid.c | 20 +-- drivers/s390/cio/device_status.c | 24 +-- drivers/s390/cio/io_sch.h | 19 ++- drivers/s390/virtio/virtio_ccw.c | 310 ++++++++++++++++++++---------------- 18 files changed, 444 insertions(+), 213 deletions(-) create mode 100644 arch/s390/include/asm/dma-mapping.h create mode 100644 arch/s390/include/asm/mem_encrypt.h -- 2.16.4
