iommufd: Use GFP_KERNEL_ACCOUNT for iommu_map()

iommufd: Use GFP_KERNEL_ACCOUNT for iommu_map()

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.

However, one of the biggest consumers of kernel memory is the IOPTEs
stored under the iommu_domain. Many drivers will allocate these at
iommu_map() time and will trivially do the right thing if we pass in
GFP_KERNEL_ACCOUNT.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v3-76b587fe28df+6e3-iommu_map_gfp_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>