On 30/11/2017 13:57, Jean-Philippe Brucker wrote:
Hello, On 30/11/17 11:34, Pierre Morel wrote: [...]+/** + * vfio_get_aperture - report minimal aperture of a vfio_iommu + * @iommu: the current vfio_iommu + * @start: a pointer to the aperture start + * @end : a pointer to the aperture end + * + * This function iterate on the domains using the given vfio_iommu + * and restrict the aperture to the minimal aperture common + * to all domains sharing this vfio_iommu. + */ +static void vfio_get_aperture(struct vfio_iommu *iommu, uint64_t *start, + uint64_t *end) +{ + struct iommu_domain_geometry geometry; + struct vfio_domain *domain; + + *start = 0; + *end = U64_MAX;I wonder if the default values should also reflect what the VFIO implementation actually supports. Looking at vfio_dma_do_map, a 32-bit host will reject any iova greater than 32 bits. In addition, vfio_dma_do_unmap doesn't support unmapping the last page of a 64-bit address space (existing IOMMUs would probably reject map requests with IOVA > 52 bits anyway, but if they don't report a domain aperture, VFIO can't guess it). I think it's convenient to use VFIO_IOMMU_UNMAP_DMA on the full address space when an unmap-all is needed, maybe we could provide default aperture values that help doing this? (~0U for 32-bit and (~0ULL - PAGE_SIZE) for 64-bit) Thanks, Jean
Thanks, I will take care of this. Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
