Re: [PATCH v2 01/15] KVM: s390: refactor crypto initialization
From: Tony Krowiak
Date: Wed Feb 28 2018 - 16:23:49 EST
On 02/28/2018 12:37 PM, Cornelia Huck wrote:
On Tue, 27 Feb 2018 09:27:59 -0500
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
The crypto control block designation (CRYCBD) is a 32-bit
field in the KVM guest's SIE state description. The
contents of bits 1-28 of this field, with three zero bits
appended on the right, designate the host real 31-bit
address of a crypto control block (CRYCB). Bits 30-31
specify the format of the CRYCB. In the current
implementation, the address of the CRYCB is stored in
the CRYCBD only if the Message-Security-Assist extension
3 (MSA3) facility is installed. Virtualization of AP
facilities, however, requires that a CRYCB of the
appropriate format be made available to SIE regardless
of whether MSA3 is installed or not.
This patch introduces a new compilation unit to provide
all interfaces related to configuration of AP facilities.
Let's start by moving the function for setting the CRYCB
format from arch/s390/kvm/kvm-s390 to this new AP
configuration interface.
Hm, I would tweak this patch description a bit. First, you talk about
what the crycbd is; then, what needs to be done for vfio-ap support;
then you simply state that you move some interfaces to a new file. I'd
like to see a connection between those parts :)
[It sounds a bit like you'd just introduce a new file and move some
functions, while you do have more changes in there.]
I'll try to wordsmith the patch description.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
---
MAINTAINERS | 10 ++++++
arch/s390/include/asm/kvm-ap.h | 16 ++++++++++
arch/s390/include/asm/kvm_host.h | 1 +
arch/s390/kvm/Makefile | 2 +-
arch/s390/kvm/kvm-ap.c | 47 ++++++++++++++++++++++++++++
arch/s390/kvm/kvm-s390.c | 62 +++++---------------------------------
6 files changed, 83 insertions(+), 55 deletions(-)
create mode 100644 arch/s390/include/asm/kvm-ap.h
create mode 100644 arch/s390/kvm/kvm-ap.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 0ec5881..4acf7c2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11875,6 +11875,16 @@ W: http://www.ibm.com/developerworks/linux/linux390/
S: Supported
F: drivers/s390/crypto/
+S390 VFIO AP DRIVER
+M: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
+M: Christian BornTraeger <borntraeger@xxxxxxxxxx>
Typo.
Will fix
+M: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
+L: linux-s390@xxxxxxxxxxxxxxx
+W: http://www.ibm.com/developerworks/linux/linux390/
+S: Supported
+F: arch/s390/include/asm/kvm/kvm-ap.h
+F: arch/s390/kvm/kvm-ap.c
+
S390 ZFCP DRIVER
M: Steffen Maier <maier@xxxxxxxxxxxxxxxxxx>
M: Benjamin Block <bblock@xxxxxxxxxxxxxxxxxx>
(...)
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?
+ if (ret)
+ return 0;
+
+ return (config.apxa == 1);
+}
+KVM guest's use.
+/**
+ * kvm_ap_set_crycb_format
+ *
+ * Set the CRYCB format in the CRYCBD for the KVM guest.
Spell out "crypto control block" somewhere?
Done
+ *
+ * @kvm: the KVM guest
+ * @crycbd: the CRYCB descriptor
+ */
+void kvm_ap_set_crycb_format(struct kvm *kvm, __u32 *crycbd)
+{
+ *crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb;
+
+ *crycbd &= ~(CRYCB_FORMAT_MASK);
+
+ /* If the MSAX3 is installed */
/* check whether MSAX3 is installed */ ?
Sure, why not
+ if (test_kvm_facility(kvm, 76)) {
+ if (kvm_ap_apxa_installed())
+ *crycbd |= CRYCB_FORMAT2;
+ else
+ *crycbd |= CRYCB_FORMAT1;
+ }
+}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5f5a4cb..de1e299 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1913,12 +1866,13 @@ static u64 kvm_s390_get_initial_cpuid(void)
static void kvm_s390_crypto_init(struct kvm *kvm)
{
+ kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb;
+ kvm->arch.crypto.crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb;
+ kvm_ap_set_crycb_format(kvm, &kvm->arch.crypto.crycbd);
Doesn't kvm_ap_set_crycb_format() already initialize its second
parameter?
Yes it does. I'm going to have to rework this (see comment below)
Would it make sense to do
kvm->arch.crypto.crycbd = kvm_ap_build_crycbd(kvm);
or so instead?
It would if this was the only place the function gets called. In patch
2, this is called
from VSIE and it wouldn't make sense in that context. I like your idea,
let me work on this
and figure out how best to make it happen.
+
if (!test_kvm_facility(kvm, 76))
return;
- kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb;
- kvm_s390_set_crycb_format(kvm);
-
/* Enable AES/DEA protected key functions by default */
kvm->arch.crypto.aes_kw = 1;
kvm->arch.crypto.dea_kw = 1;