On 23/03/2026 20:47, Ackerley Tng wrote:
"David Hildenbrand (Arm)" <[email protected]> writes:
[...snip...]
+static int kvm_gmem_folio_zap_direct_map(struct folio *folio)
+{
+ u64 gmem_flags = GMEM_I(folio_inode(folio))->flags;
+ int r = 0;
+
+ if (kvm_gmem_folio_no_direct_map(folio) || !(gmem_flags &
GUEST_MEMFD_FLAG_NO_DIRECT_MAP))
The function is only called when
kvm_gmem_no_direct_map(folio_inode(folio))
Does it really make sense to check for GUEST_MEMFD_FLAG_NO_DIRECT_MAP again?
Good point that GUEST_MEMFD_FLAG_NO_DIRECT_MAP was already checked in
the caller. I think we can drop this second check.
Dropped, thanks.
If, at all, it should be a warning if GUEST_MEMFD_FLAG_NO_DIRECT_MAP is
not set?
Further, kvm_gmem_folio_zap_direct_map() uses the folio lock to
synchronize, right? Might be worth pointing that out somehow (e.g.,
lockdep check if possible).
+ goto out;
+
+ r = folio_zap_direct_map(folio);
+ if (!r)
+ folio->private = (void *)((u64)folio->private |
KVM_GMEM_FOLIO_NO_DIRECT_MAP);
+
+out:
+ return r;
+}
+
+static void kvm_gmem_folio_restore_direct_map(struct folio *folio)
+{
