KVM: MMU: Use __set_spte to link shadow pages

To avoid split accesses to 64 bit sptes on i386, use __set_spte() to link
shadow pages together.

(not technically required since shadow pages are __GFP_KERNEL, so upper 32
bits are always clear)

Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index df3a7a7..5a6019a 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1489,7 +1489,7 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
        spte = __pa(sp->spt)
                | PT_PRESENT_MASK | PT_ACCESSED_MASK
                | PT_WRITABLE_MASK | PT_USER_MASK;
-       *sptep = spte;
+       __set_spte(sptep, spte);
 }
 
 static void kvm_mmu_page_unlink_children(struct kvm *kvm,