The vfio_iommu_spapr_tce driver advertises kernel's support for v1 and v2 IOMMU support, however it is not always possible to use the requested IOMMU type. For example, a pseries host platform does not support dynamic DMA windows so v2 cannot initialize and QEMU fails to start.
This adds a fallback to the v1 IOMMU if v2 cannot be used. Fixes: 318f67ce1371 "vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2)" Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> --- Changes: v2: * updated commit log --- hw/vfio/common.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 7b2924c..cd81cc9 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1040,6 +1040,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU; ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); if (ret) { + container->iommu_type = VFIO_SPAPR_TCE_IOMMU; + v2 = false; + ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); + } + if (ret) { error_setg_errno(errp, errno, "failed to set iommu for container"); ret = -errno; goto free_container_exit; -- 2.11.0