KVM: x86/mmu: Ignore CR0 and CR4 bits in nested EPT MMU role

Do not incorporate CR0/CR4 bits into the role for the nested EPT MMU, as
EPT behavior is not influenced by CR0/CR4. Note, this is the guest_mmu,
(L1's EPT), not nested_mmu (L2's IA32 paging); the nested_mmu does need
CR0/CR4, and is initialized in a separate flow.

Signed-off-by: Sean Christopherson <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

arch/x86/kvm/mmu/mmu.c

···
 	role.base.guest_mode = true;
 	role.base.access = ACC_ALL;
 
-	role.ext = kvm_calc_mmu_role_ext(vcpu);
+	/* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */
+	role.ext.word = 0;
 	role.ext.execonly = execonly;
+	role.ext.valid = 1;
 
 	return role;
 }