• Joerg Roedel's avatar
    Merge branch 'iommu-memory-accounting' into core · ff489fe0
    Joerg Roedel authored
    Merge patch-set from Jason:
    
    	"Let iommufd charge IOPTE allocations to the memory cgroup"
    
    Description:
    
    IOMMUFD follows the same design as KVM and uses memory cgroups to limit
    the amount of kernel memory a iommufd file descriptor can pin down. The
    various internal data structures already use GFP_KERNEL_ACCOUNT to charge
    its own memory.
    
    However, one of the biggest consumers of kernel memory is the IOPTEs
    stored under the iommu_domain and these allocations are not tracked.
    
    This series is the first step in fixing it.
    
    The iommu driver contract already includes a 'gfp' argument to the
    map_pages op, allowing iommufd to specify GFP_KERNEL_ACCOUNT and then
    having the driver allocate the IOPTE tables with that flag will capture a
    significant amount of the allocations.
    
    Update the iommu_map() API to pass in the GFP argument, and fix all call
    sites. Replace iommu_map_atomic().
    
    Audit the "enterprise" iommu drivers to make sure they do the right thing.
    Intel and S390 ignore the GFP argument and always use GFP_ATOMIC. This is
    problematic for iommufd anyhow, so fix it. AMD and ARM SMMUv2/3 are
    already correct.
    
    A follow up series will be needed to capture the allocations made when the
    iommu_domain itself is allocated, which will complete the job.
    
    Link: https://lore.kernel.org/linux-iommu/0-v3-76b587fe28df+6e3-iommu_map_gfp_jgg@nvidia.com/
    ff489fe0
iommu.h 36 KB