KVM: MMU: remove oos_shadow parameter

The unsync code should be stable now, maybe it is the time to remove this
parameter to cleanup the code a little bit

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

Documentation/kernel-parameters.txt

@@ -1178,9 +1178,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
 			Default is 0 (don't ignore, but inject #GP)
 
-	kvm.oos_shadow=	[KVM] Disable out-of-sync shadow paging.
-			Default is 1 (enabled)
-
 	kvm.mmu_audit=	[KVM] This is a R/W parameter which allows audit
 			KVM MMU at runtime.
 			Default is 0 (off)

arch/x86/kvm/mmu.c

@@ -93,9 +93,6 @@ static int dbg = 0;
 module_param(dbg, bool, 0644);
 #endif
 
-static int oos_shadow = 1;
-module_param(oos_shadow, bool, 0644);
-
 #ifndef MMU_DEBUG
 #define ASSERT(x) do { } while (0)
 #else
@@ -2196,8 +2193,6 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 			return 1;
 
 		if (!need_unsync && !s->unsync) {
-			if (!oos_shadow)
-				return 1;
 			need_unsync = true;
 		}
 	}