| From: Yang Shi <yang@os.amperecomputing.com> |
| Subject: hugetlbfs: add MTE support |
| Date: Tue, 25 Jun 2024 16:37:17 -0700 |
| |
| MTE can be supported on ram based filesystem. It is supported on tmpfs. |
| There is use case to use MTE on hugetlbfs as well, adding MTE support. |
| |
| Exercising this capability requires special arrangements. This needs |
| hardware support and custom-patched QEMU. We did in-house testing on |
| AmpereOne platform with patched QEMU 8.1. |
| |
| Custom-patched QEMU is not required for a minimum test. But a special |
| test program is definitely needed. We used custom-patched QEMU to test |
| VM backed by hugetlbfs with MTE enabled. |
| |
| Link: https://lkml.kernel.org/r/20240625233717.2769975-1-yang@os.amperecomputing.com |
| Signed-off-by: Yang Shi <yang@os.amperecomputing.com> |
| Cc: Catalin Marinas <catalin.marinas@arm.com> |
| Cc: Muchun Song <muchun.song@linux.dev> |
| Cc: Will Deacon <will@kernel.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| fs/hugetlbfs/inode.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/fs/hugetlbfs/inode.c~hugetlbfs-add-mte-support |
| +++ a/fs/hugetlbfs/inode.c |
| @@ -110,7 +110,7 @@ static int hugetlbfs_file_mmap(struct fi |
| * way when do_mmap unwinds (may be important on powerpc |
| * and ia64). |
| */ |
| - vm_flags_set(vma, VM_HUGETLB | VM_DONTEXPAND); |
| + vm_flags_set(vma, VM_HUGETLB | VM_DONTEXPAND | VM_MTE_ALLOWED); |
| vma->vm_ops = &hugetlb_vm_ops; |
| |
| ret = seal_check_write(info->seals, vma); |
| _ |
