Commit 17573fd9 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: guest_memfd: extract __kvm_gmem_get_pfn() 



In preparation for adding a function that walks a set of pages
provided by userspace and populates them in a guest_memfd,
add a version of kvm_gmem_get_pfn() that has a "bool prepare"
argument and passes it down to kvm_gmem_get_folio().

Populating guest memory has to call repeatedly __kvm_gmem_get_pfn()
on the same file, so make the new function take struct file*.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3bb2531e

virt/kvm/guest_memfd.c

+24 −16
Original line number Diff line number Diff line
@@ -528,33 +528,29 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) 
	fput(file);

}



int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,

		     gfn_t gfn, kvm_pfn_t *pfn, int *max_order)

static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot,

		       gfn_t gfn, kvm_pfn_t *pfn, int *max_order, bool prepare)

{

	pgoff_t index = gfn - slot->base_gfn + slot->gmem.pgoff;

	struct kvm_gmem *gmem;

	struct kvm_gmem *gmem = file->private_data;

	struct folio *folio;

	struct page *page;

	struct file *file;

	int r;



	file = kvm_gmem_get_file(slot);

	if (!file)

	if (file != slot->gmem.file) {

		WARN_ON_ONCE(slot->gmem.file);

		return -EFAULT;

	}



	gmem = file->private_data;



	if (xa_load(&gmem->bindings, index) != slot) {

		WARN_ON_ONCE(xa_load(&gmem->bindings, index));

		r = -EIO;

		goto out_fput;

		return -EIO;

	}



	folio = kvm_gmem_get_folio(file_inode(file), index, true);

	if (IS_ERR(folio)) {

		r = PTR_ERR(folio);

		goto out_fput;

	}

	folio = kvm_gmem_get_folio(file_inode(file), index, prepare);

	if (IS_ERR(folio))

		return PTR_ERR(folio);



	if (folio_test_hwpoison(folio)) {

		r = -EHWPOISON;
@@ -571,9 +567,21 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, 


out_unlock:

	folio_unlock(folio);

out_fput:

	fput(file);



	return r;

}



int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,

		     gfn_t gfn, kvm_pfn_t *pfn, int *max_order)

{

	struct file *file = kvm_gmem_get_file(slot);

	int r;



	if (!file)

		return -EFAULT;



	r = __kvm_gmem_get_pfn(file, slot, gfn, pfn, max_order, true);

	fput(file);

	return r;

}

EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn);