On Tue, Nov 28, 2023 at 5:59 PM Robin Murphy <robin.murphy@xxxxxxx> wrote: > > On 2023-11-28 10:50 pm, Pasha Tatashin wrote: > > On Tue, Nov 28, 2023 at 5:34 PM Robin Murphy <robin.murphy@xxxxxxx> wrote: > >> > >> On 2023-11-28 8:49 pm, Pasha Tatashin wrote: > >>> Convert iommu/dma-iommu.c to use the new page allocation functions > >>> provided in iommu-pages.h. > >> > >> These have nothing to do with IOMMU pagetables, they are DMA buffers and > >> they belong to whoever called the corresponding dma_alloc_* function. > > > > Hi Robin, > > > > This is true, however, we want to account and observe the pages > > allocated by IOMMU subsystem for DMA buffers, as they are essentially > > unmovable locked pages. Should we separate IOMMU memory from KVM > > memory all together and add another field to /proc/meminfo, something > > like "iommu -> iommu pagetable and dma memory", or do we want to > > export DMA memory separately from IOMMU page tables? > > These are not allocated by "the IOMMU subsystem", they are allocated by > the DMA API. Even if you want to claim that a driver pinning memory via > iommu_dma_ops is somehow different from the same driver pinning the same > amount of memory via dma-direct when iommu.passthrough=1, it's still > nonsense because you're failing to account the pages which iommu_dma_ops > gets from CMA, dma_common_alloc_pages(), dynamic SWIOTLB, the various > pools, and so on. > > Thanks, > Robin. > > > Since, I included DMA memory, I specifically removed mentioning of > > IOMMU page tables in the most of places, and only report it as IOMMU > > memory. However, since it is still bundled together with SecPageTables > > it can be confusing. > > > > Pasha
