On Wed, Jun 26, 2024 at 1:45 PM Yang Shi <shy828301@xxxxxxxxx> wrote: > > On Wed, Jun 26, 2024 at 1:40 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > On Tue, 25 Jun 2024 16:37:17 -0700 Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > 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. > > > > > > --- a/fs/hugetlbfs/inode.c > > > +++ b/fs/hugetlbfs/inode.c > > > @@ -110,7 +110,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) > > > * 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); > > > > How thoroughly has this been tested? > > > > Can we expect normal linux-next testing to exercise this, or must > > testers make special arangements to get the coverage? > > It requires special arrangements. This needs hardware support and > custom-patched QEMU. We did in-house test on AmpereOne platform with > patched QEMU 8.1. To correct, 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. > > >
