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

Peter Xu
2025-02-25T20:37:16Z

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
>

--
Peter Xu