This adds a flag to enable/disable bypassing the IOMMU by virtio devices. This is on top of patch http://article.gmane.org/gmane.comp.emulators.qemu/403467 virtio: convert to use DMA api Tested with patchset http://article.gmane.org/gmane.linux.kernel.virtualization/27545 virtio-pci: iommu support Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> --- include/hw/virtio/virtio-access.h | 3 ++- include/hw/virtio/virtio.h | 6 +++++- include/standard-headers/linux/virtio_config.h | 8 ++++++++ 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/hw/virtio/virtio-access.h b/include/hw/virtio/virtio-access.h index 967cc75..bb6f34e 100644 --- a/include/hw/virtio/virtio-access.h +++ b/include/hw/virtio/virtio-access.h @@ -23,7 +23,8 @@ static inline AddressSpace *virtio_get_dma_as(VirtIODevice *vdev) BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); - if (k->get_dma_as) { + if ((vdev->host_features & (0x1ULL << VIRTIO_F_IOMMU_PLATFORM)) && + k->get_dma_as) { return k->get_dma_as(qbus->parent); } return &address_space_memory; diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index b12faa9..34d3041 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -228,7 +228,11 @@ typedef struct VirtIORNGConf VirtIORNGConf; DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ VIRTIO_F_NOTIFY_ON_EMPTY, true), \ DEFINE_PROP_BIT64("any_layout", _state, _field, \ - VIRTIO_F_ANY_LAYOUT, true) + VIRTIO_F_ANY_LAYOUT, true), \ + DEFINE_PROP_BIT64("iommu_passthrough", _state, _field, \ + VIRTIO_F_IOMMU_PASSTHROUGH, false), \ + DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ + VIRTIO_F_IOMMU_PLATFORM, false) hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); diff --git a/include/standard-headers/linux/virtio_config.h b/include/standard-headers/linux/virtio_config.h index bcc445b..5564dab 100644 --- a/include/standard-headers/linux/virtio_config.h +++ b/include/standard-headers/linux/virtio_config.h @@ -61,4 +61,12 @@ /* v1.0 compliant. */ #define VIRTIO_F_VERSION_1 32 +/* Request IOMMU passthrough (if available) + * Without VIRTIO_F_IOMMU_PLATFORM: bypass the IOMMU even if enabled. + * With VIRTIO_F_IOMMU_PLATFORM: suggest disabling IOMMU. + */ +#define VIRTIO_F_IOMMU_PASSTHROUGH 33 + +/* Do not bypass the IOMMU (if configured) */ +#define VIRTIO_F_IOMMU_PLATFORM 34 #endif /* _LINUX_VIRTIO_CONFIG_H */ -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
