Kernel commit 492855939bdb added a limit to the number of outstanding DMA requests for a type1 vfio container. However, lazy unmapping in s390 can in fact cause quite a large number of outstanding DMA requests to build up prior to being purged, potentially the entire guest DMA space. This results in unexpected 'VFIO_MAP_DMA failed: No space left on device' conditions seen in QEMU. This patchset adds support to qemu to retrieve the number of allowable DMA requests via the VFIO_IOMMU_GET_INFO ioctl. The patches are separated into vfio hits which add support for reading in VFIO_IOMMU_GET_INFO capability chains and getting the per-container dma_avail value, and s390 hits to track DMA usage on a per-container basis. Associated kernel patch: https://marc.info/?l=kvm&m=160019703922812&w=2 Changes from v3: - Patch 2,3: Added RBs provided (thank you!) - Patch 4: retry the ioctl in the same manner as vfio_get_region_info - Patch 5: switch to static inline functions - Patch 5: relocate more code to s390-pci-vfio.* Matthew Rosato (5): linux-headers: update against 5.9-rc5 vfio: Create shared routine for scanning info capabilities vfio: Find DMA available capability s390x/pci: Add routine to get the vfio dma available count s390x/pci: Honor DMA limits set by vfio hw/s390x/meson.build | 1 + hw/s390x/s390-pci-bus.c | 16 ++- hw/s390x/s390-pci-bus.h | 9 ++ hw/s390x/s390-pci-inst.c | 45 ++++++- hw/s390x/s390-pci-inst.h | 3 + hw/s390x/s390-pci-vfio.c | 96 ++++++++++++++ hw/s390x/s390-pci-vfio.h | 22 ++++ hw/vfio/common.c | 52 ++++++-- include/hw/vfio/vfio-common.h | 2 + include/standard-headers/drm/drm_fourcc.h | 140 +++++++++++++++++++++ include/standard-headers/linux/ethtool.h | 87 +++++++++++++ include/standard-headers/linux/input-event-codes.h | 3 +- include/standard-headers/linux/vhost_types.h | 11 ++ include/standard-headers/linux/virtio_9p.h | 4 +- include/standard-headers/linux/virtio_blk.h | 26 ++-- include/standard-headers/linux/virtio_config.h | 8 +- include/standard-headers/linux/virtio_console.h | 8 +- include/standard-headers/linux/virtio_net.h | 6 +- include/standard-headers/linux/virtio_scsi.h | 20 +-- linux-headers/asm-generic/unistd.h | 6 +- linux-headers/asm-mips/unistd_n32.h | 1 + linux-headers/asm-mips/unistd_n64.h | 1 + linux-headers/asm-mips/unistd_o32.h | 1 + linux-headers/asm-powerpc/kvm.h | 5 + linux-headers/asm-powerpc/unistd_32.h | 1 + linux-headers/asm-powerpc/unistd_64.h | 1 + linux-headers/asm-s390/kvm.h | 7 +- linux-headers/asm-s390/unistd_32.h | 1 + linux-headers/asm-s390/unistd_64.h | 1 + linux-headers/asm-x86/unistd_32.h | 1 + linux-headers/asm-x86/unistd_64.h | 1 + linux-headers/asm-x86/unistd_x32.h | 1 + linux-headers/linux/kvm.h | 10 +- linux-headers/linux/vfio.h | 17 ++- linux-headers/linux/vhost.h | 2 + 35 files changed, 554 insertions(+), 62 deletions(-) create mode 100644 hw/s390x/s390-pci-vfio.c create mode 100644 hw/s390x/s390-pci-vfio.h -- 1.8.3.1
