path: root/arch/s390/include/uapi
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authorHarald Freudenberger <freude@linux.ibm.com>2018-09-17 14:18:41 (GMT)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-10-08 07:09:58 (GMT)
commit00fab2350e6b91e57b3cdcd5d9f01056775a921d (patch)
tree7eb7828e1ade8597e437730f4fd0147e3f28cbdd /arch/s390/include/uapi
parentccc413f621432fcb5dabb751d42148795f59a816 (diff)
s390/zcrypt: multiple zcrypt device nodes support
This patch is an extension to the zcrypt device driver to provide, support and maintain multiple zcrypt device nodes. The individual zcrypt device nodes can be restricted in terms of crypto cards, domains and available ioctls. Such a device node can be used as a base for container solutions like docker to control and restrict the access to crypto resources. The handling is done with a new sysfs subdir /sys/class/zcrypt. Echoing a name (or an empty sting) into the attribute "create" creates a new zcrypt device node. In /sys/class/zcrypt a new link will appear which points to the sysfs device tree of this new device. The attribute files "ioctlmask", "apmask" and "aqmask" in this directory are used to customize this new zcrypt device node instance. Finally the zcrypt device node can be destroyed by echoing the name into /sys/class/zcrypt/destroy. The internal structs holding the device info are reference counted - so a destroy will not hard remove a device but only marks it as removable when the reference counter drops to zero. The mask values are bitmaps in big endian order starting with bit 0. So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs attributes accept 2 different formats: * Absolute hex string starting with 0x like "0x12345678" does set the mask starting from left to right. If the given string is shorter than the mask it is padded with 0s on the right. If the string is longer than the mask an error comes back (EINVAL). * Relative format - a concatenation (done with ',') of the terms +<bitnr>[-<bitnr>] or -<bitnr>[-<bitnr>]. <bitnr> may be any valid number (hex, decimal or octal) in the range 0...255. Here are some examples: "+0-15,+32,-128,-0xFF" "-0-255,+1-16,+0x128" "+1,+2,+3,+4,-5,-7-10" A simple usage examples: # create new zcrypt device 'my_zcrypt': echo "my_zcrypt" >/sys/class/zcrypt/create # go into the device dir of this new device echo "my_zcrypt" >create cd my_zcrypt/ ls -l total 0 -rw-r--r-- 1 root root 4096 Jul 20 15:23 apmask -rw-r--r-- 1 root root 4096 Jul 20 15:23 aqmask -r--r--r-- 1 root root 4096 Jul 20 15:23 dev -rw-r--r-- 1 root root 4096 Jul 20 15:23 ioctlmask lrwxrwxrwx 1 root root 0 Jul 20 15:23 subsystem -> ../../../../class/zcrypt ... # customize this zcrypt node clone # enable only adapter 0 and 2 echo "0xa0" >apmask # enable only domain 6 echo "+6" >aqmask # enable all 256 ioctls echo "+0-255" >ioctls # now the /dev/my_zcrypt may be used # finally destroy it echo "my_zcrypt" >/sys/class/zcrypt/destroy Please note that a very similar 'filtering behavior' also applies to the parent z90crypt device. The two mask attributes apmask and aqmask in /sys/bus/ap act the very same for the z90crypt device node. However the implementation here is totally different as the ap bus acts on bind/unbind of queue devices and associated drivers but the effect is still the same. So there are two filters active for each additional zcrypt device node: The adapter/domain needs to be enabled on the ap bus level and it needs to be active on the zcrypt device node level. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/uapi')
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/s390/include/uapi/asm/zcrypt.h b/arch/s390/include/uapi/asm/zcrypt.h
index 2bb1f3b..196a304 100644
--- a/arch/s390/include/uapi/asm/zcrypt.h
+++ b/arch/s390/include/uapi/asm/zcrypt.h
@@ -2,9 +2,9 @@
* include/asm-s390/zcrypt.h
- * zcrypt 2.1.0 (user-visible header)
+ * zcrypt 2.2.0 (user-visible header)
- * Copyright IBM Corp. 2001, 2006
+ * Copyright IBM Corp. 2001, 2018
* Author(s): Robert Burroughs
* Eric Rossman (edrossma@us.ibm.com)
@@ -15,12 +15,15 @@
#define __ASM_S390_ZCRYPT_H
#include <linux/ioctl.h>
#include <linux/compiler.h>
+/* Name of the zcrypt device driver. */
+#define ZCRYPT_NAME "zcrypt"
* struct ica_rsa_modexpo
@@ -310,6 +313,16 @@ struct zcrypt_device_matrix_ext {
+ * Support for multiple zcrypt device nodes.
+ */
+/* Nr of minor device node numbers to allocate. */
+/* Max amount of possible ioctls */
* Only deprecated defines, structs and ioctls below this line.

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