1 files changed, 56 insertions, 2 deletions

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 88fd812f0f31..4463643bd0a2 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -4,6 +4,7 @@
 #include <linux/falloc.h>
 #include <linux/fs.h>
 #include <linux/kvm_host.h>
+#include <linux/mempolicy.h>
 #include <linux/pseudo_fs.h>
 #include <linux/pagemap.h>
 
@@ -27,6 +28,7 @@ struct gmem_file {
 };
 
 struct gmem_inode {
+	struct shared_policy policy;
 	struct inode vfs_inode;
 };
 
@@ -129,7 +131,25 @@ static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot,
 static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index)
 {
 	/* TODO: Support huge pages. */
-	return filemap_grab_folio(inode->i_mapping, index);
+	struct mempolicy *policy;
+	struct folio *folio;
+
+	/*
+	 * Fast-path: See if folio is already present in mapping to avoid
+	 * policy_lookup.
+	 */
+	folio = __filemap_get_folio(inode->i_mapping, index,
+				    FGP_LOCK | FGP_ACCESSED, 0);
+	if (!IS_ERR(folio))
+		return folio;
+
+	policy = mpol_shared_policy_lookup(&GMEM_I(inode)->policy, index);
+	folio = __filemap_get_folio_mpol(inode->i_mapping, index,
+					 FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+					 mapping_gfp_mask(inode->i_mapping), policy);
+	mpol_cond_put(policy);
+
+	return folio;
 }
 
 static enum kvm_gfn_range_filter kvm_gmem_get_invalidate_filter(struct inode *inode)
@@ -411,8 +431,40 @@ out_folio:
 	return ret;
 }
 
+#ifdef CONFIG_NUMA
+static int kvm_gmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+
+	return mpol_set_shared_policy(&GMEM_I(inode)->policy, vma, mpol);
+}
+
+static struct mempolicy *kvm_gmem_get_policy(struct vm_area_struct *vma,
+					     unsigned long addr, pgoff_t *pgoff)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+
+	*pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+
+	/*
+	 * Return the memory policy for this index, or NULL if none is set.
+	 *
+	 * Returning NULL, e.g. instead of the current task's memory policy, is
+	 * important for the .get_policy kernel ABI: it indicates that no
+	 * explicit policy has been set via mbind() for this memory. The caller
+	 * can then replace NULL with the default memory policy instead of the
+	 * current task's memory policy.
+	 */
+	return mpol_shared_policy_lookup(&GMEM_I(inode)->policy, *pgoff);
+}
+#endif /* CONFIG_NUMA */
+
 static const struct vm_operations_struct kvm_gmem_vm_ops = {
-	.fault = kvm_gmem_fault_user_mapping,
+	.fault		= kvm_gmem_fault_user_mapping,
+#ifdef CONFIG_NUMA
+	.get_policy	= kvm_gmem_get_policy,
+	.set_policy	= kvm_gmem_set_policy,
+#endif
 };
 
 static int kvm_gmem_mmap(struct file *file, struct vm_area_struct *vma)
@@ -864,11 +916,13 @@ static struct inode *kvm_gmem_alloc_inode(struct super_block *sb)
 	if (!gi)
 		return NULL;
 
+	mpol_shared_policy_init(&gi->policy, NULL);
 	return &gi->vfs_inode;
 }
 
 static void kvm_gmem_destroy_inode(struct inode *inode)
 {
+	mpol_free_shared_policy(&GMEM_I(inode)->policy);
 }
 
 static void kvm_gmem_free_inode(struct inode *inode)