Commit d0d87226 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: guest_memfd: return folio from __kvm_gmem_get_pfn() 



Right now this is simply more consistent and avoids use of pfn_to_page()
and put_page().  It will be put to more use in upcoming patches, to
ensure that the up-to-date flag is set at the very end of both the
kvm_gmem_get_pfn() and kvm_gmem_populate() flows.

Reviewed-by: default avatarMichael Roth <michael.roth@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5932ca41

virt/kvm/guest_memfd.c

+20 −17
Original line number Diff line number Diff line
@@ -541,34 +541,34 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) 
	fput(file);

}



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

static struct folio *

__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 = file->private_data;

	struct folio *folio;

	struct page *page;

	int r;



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

		WARN_ON_ONCE(slot->gmem.file);

		return -EFAULT;

		return ERR_PTR(-EFAULT);

	}



	gmem = file->private_data;

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

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

		return -EIO;

		return ERR_PTR(-EIO);

	}



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

	if (IS_ERR(folio))

		return PTR_ERR(folio);

		return folio;



	if (folio_test_hwpoison(folio)) {

		folio_unlock(folio);

		folio_put(folio);

		return -EHWPOISON;

		return ERR_PTR(-EHWPOISON);

	}



	page = folio_file_page(folio, index);
@@ -577,25 +577,25 @@ static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot, 
	if (max_order)

		*max_order = 0;



	r = 0;



	folio_unlock(folio);



	return r;

	return folio;

}



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;

	struct folio *folio;



	if (!file)

		return -EFAULT;



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

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

	fput(file);

	return r;

	if (IS_ERR(folio))

		return PTR_ERR(folio);



	return 0;

}

EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn);
@@ -625,6 +625,7 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long 


	npages = min_t(ulong, slot->npages - (start_gfn - slot->base_gfn), npages);

	for (i = 0; i < npages; i += (1 << max_order)) {

		struct folio *folio;

		gfn_t gfn = start_gfn + i;

		kvm_pfn_t pfn;
@@ -633,9 +634,11 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long 
			break;

		}



		ret = __kvm_gmem_get_pfn(file, slot, gfn, &pfn, &max_order, false);

		if (ret)

		folio = __kvm_gmem_get_pfn(file, slot, gfn, &pfn, &max_order, false);

		if (IS_ERR(folio)) {

			ret = PTR_ERR(folio);

			break;

		}



		if (!IS_ALIGNED(gfn, (1 << max_order)) ||

		    (npages - i) < (1 << max_order))
@@ -644,7 +647,7 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long 
		p = src ? src + i * PAGE_SIZE : NULL;

		ret = post_populate(kvm, gfn, pfn, p, max_order, opaque);



		put_page(pfn_to_page(pfn));

		folio_put(folio);

		if (ret)

			break;

	}