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: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-07-11 18:27:48 -04:00
parent 564429a6bd
commit 78c4293372

View File

@ -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;