Commit 78c42933 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: guest_memfd: return locked folio from __kvm_gmem_get_pfn 



Allow testing the up-to-date flag in the caller without taking the
lock again.

Reviewed-by: default avatarMichael Roth <michael.roth@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 564429a6

virt/kvm/guest_memfd.c

+4 −1
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ static int kvm_gmem_prepare_folio(struct inode *inode, pgoff_t index, struct fol 
	return 0;

}



/* Returns a locked folio on success.  */

static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, bool prepare)

{

	struct folio *folio;
@@ -551,6 +552,7 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) 
	fput(file);

}



/* Returns a locked folio on success.  */

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)
@@ -584,7 +586,6 @@ __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot, 
	if (max_order)

		*max_order = 0;



	folio_unlock(folio);

	return folio;

}
@@ -602,6 +603,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, 
	if (IS_ERR(folio))

		return PTR_ERR(folio);



	folio_unlock(folio);

	return 0;

}

EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn);
@@ -647,6 +649,7 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long 
			break;

		}



		folio_unlock(folio);

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

		    (npages - i) < (1 << max_order))

			max_order = 0;