Re: [PATCH v2 01/15] KVM: s390: refactor crypto initialization
From: Tony Krowiak
Date: Wed Mar 14 2018 - 12:02:28 EST
On 03/01/2018 04:59 AM, Cornelia Huck wrote:
On Wed, 28 Feb 2018 16:23:29 -0500
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
On 02/28/2018 12:37 PM, Cornelia Huck wrote:
On Tue, 27 Feb 2018 09:27:59 -0500
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
diff --git a/arch/s390/kvm/kvm-ap.c b/arch/s390/kvm/kvm-ap.c
new file mode 100644
index 0000000..5305f4c
--- /dev/null
+++ b/arch/s390/kvm/kvm-ap.c
@@ -0,0 +1,47 @@
+/*
+ * Adjunct Processor (AP) configuration management for KVM guests
+ *
+ * Copyright IBM Corp. 2017
+ *
+ * Author(s): Tony Krowiak <akrowia@xxxxxxxxxxxxxxxxxx>
+ */
+
+#include <asm/kvm-ap.h>
+#include <asm/ap.h>
+
+#include "kvm-s390.h"
+
+static int kvm_ap_apxa_installed(void)
+{
+ int ret;
+ struct ap_config_info config;
+
+ ret = ap_query_configuration(&config);
Doesn't that introduce a dependency on CONFIG_ZCRYPT?
It does, but AFAIK zcrypt is built into the kernel. Or is that not what
you are asking?
It is built into the kernel (and not into a module) if CONFIG_ZCRYPT is
set. When I compile a kernel with CONFIG_KVM set and CONFIG_ZCRYPT
unset, with this patch applied I get
arch/s390/kvm/kvm-ap.o: In function `kvm_ap_apxa_installed':
/home/cohuck/git/linux/arch/s390/kvm/kvm-ap.c:19: undefined reference to `ap_query_configuration'
So I'm afraid you cannot use ap_query_configuration() in base s390 kvm
code unless you move that function to a place where it is always built
(or at least always built if either CONFIG_KVM or CONFIG_ZCRYPT are
set).
I was able to get around this by inserting the following into
arch/s390/kvm/Kconfig:
config KVM
def_tristate y
prompt "Kernel-based Virtual Machine (KVM) support"
depends on HAVE_KVM
select PREEMPT_NOTIFIERS
...
select ZCRYPT
If this is a problem, we can discuss it in the v3 which is forthcoming
very shortly