Messages in this thread | | | Subject | Re: [PATCH] vfio/iommu_type1: report the IOMMU aperture info | From | Pierre Morel <> | Date | Thu, 30 Nov 2017 15:16:03 +0100 |
| |
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
| |