Re: [RFC PATCH 26/39] KVM: guest_memfd: Track faultability within a struct kvm_gmem_private

On Tue, Sep 10, 2024 at 11:43:57PM +0000, Ackerley Tng wrote:

@@ -1079,12 +1152,20 @@ static struct inode *kvm_gmem_inode_make_secure_inode(const char *name, if (err) goto out;

• err = -ENOMEM;
• private = kzalloc(sizeof(*private), GFP_KERNEL);
• if (!private)

• goto out;
  

• if (flags & KVM_GUEST_MEMFD_HUGETLB) {

• err = kvm_gmem_hugetlb_setup(inode, size, flags);
  

• err = kvm_gmem_hugetlb_setup(inode, private, size, flags);
  

  if (err)

• 	goto out;
  

• 	goto free_private;
  

  }

• xa_init(&private->faultability);
• inode->i_mapping->i_private_data = private;
• inode->i_private = (void *)(unsigned long)flags;

Looks like inode->i_private isn't used before this series; the flags was always zero before anyway. Maybe it could keep kvm_gmem_inode_private instead? Then make the flags be part of the struct.

It avoids two separate places (inode->i_mapping->i_private_data, inode->i_private) to store gmem private info.

inode->i_op = &kvm_gmem_iops; inode->i_mapping->a_ops = &kvm_gmem_aops; @@ -1097,6 +1178,8 @@ static struct inode *kvm_gmem_inode_make_secure_inode(const char *name, return inode; +free_private:

• kfree(private);

out: iput(inode); -- 2.46.0.598.g6f2099f65c-goog