2 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 31ebb59cbd2f..f7df0a3b031d 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -381,6 +381,8 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
                           unsigned long len);
 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);
+int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                           void *data, unsigned long len);
 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
                          int offset, int len);
 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 11d2783eb9df..d5ef9ebcaff7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1418,6 +1418,26 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
 }
 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
 
+int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                           void *data, unsigned long len)
+{
+        struct kvm_memslots *slots = kvm_memslots(kvm);
+        int r;
+
+        if (slots->generation != ghc->generation)
+                kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
+
+        if (kvm_is_error_hva(ghc->hva))
+                return -EFAULT;
+
+        r = __copy_from_user(data, (void __user *)ghc->hva, len);
+        if (r)
+                return -EFAULT;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
+
 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
 {
         return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,