KVM: MMU: make spte_is_locklessly_modifiable() more clear

spte_is_locklessly_modifiable() checks that both SPTE_HOST_WRITEABLE and
SPTE_MMU_WRITEABLE are present on spte. Make it more explicit.

Signed-off-by: Gleb Natapov <gleb@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 9f628f7..2fa82b0 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -448,7 +448,8 @@ static bool __check_direct_spte_mmio_pf(u64 spte)
 
 static bool spte_is_locklessly_modifiable(u64 spte)
 {
-       return !(~spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE));
+       return (spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE)) ==
+               (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE);
 }
 
 static bool spte_has_volatile_bits(u64 spte)