From 78c4293372fe1fe6060727dfbd5643552e3ff86d Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 11 Jul 2024 18:27:48 -0400 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini --- virt/kvm/guest_memfd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 76139332f2f3..9271aba9b7b3 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -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;