KVM: SVM: remove needless mmap_sem acquision from nested_svm_map

nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since
gfn_to_page / get_user_pages are responsible for it.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 92048a626d4e..f54c4f9d2865 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1396,10 +1396,7 @@ static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, enum km_type idx)
 {
         struct page *page;
 
-        down_read(&current->mm->mmap_sem);
         page = gfn_to_page(svm->vcpu.kvm, gpa >> PAGE_SHIFT);
-        up_read(&current->mm->mmap_sem);
-
         if (is_error_page(page))
                 goto error;