KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped

commit 73cb8556 upstream.

... as a malicious userspace can run a toy guest to generate invalid
virtual-APIC page addresses in L1, i.e. flood the kernel log with error
messages.

Fixes: 69090810 ("KVM: nVMX: allow tests to use bad virtual-APIC page address")
Cc: stable@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/kvm/vmx/nested.c

@@ -2891,9 +2891,6 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
 			 */
 			vmcs_clear_bits(CPU_BASED_VM_EXEC_CONTROL,
 					CPU_BASED_TPR_SHADOW);
-		} else {
-			printk("bad virtual-APIC page address\n");
-			dump_vmcs();
 		}
 	}