Re: [RFC 08/19] s390/zcrypt: support for assigning adapters to matrix mdev
From: Tony Krowiak
Date: Thu Nov 16 2017 - 18:53:32 EST
On 11/14/2017 08:22 AM, Cornelia Huck wrote:
On Fri, 13 Oct 2017 13:38:53 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
Provides the sysfs interfaces for assigning an adapter to
and unassigning an AP adapter from a mediated matrix device.
The IDs of the AP adapters assigned to the mediated matrix
device are stored in a bit mask. The bits in the mask, from
left to right, correspond to AP adapter numbers 0 to 255. The
bit corresponding to the ID of the adapter being assigned will
be set in the bit mask.
The relevant sysfs structures are:
/sys/devices/ap_matrix
... [matrix]
...... [mdev_supported_types]
......... [ap_matrix-passthrough]
............ [devices]
...............[$uuid]
.................. adapters
.................. assign_adapter
.................. unassign_adapter
To assign an adapter to the $uuid mediated matrix device, write
ID of the adapter (hex value) to the assign_adapter file. To
unassign an adapter, write the ID of the adapter (hex value)
to the unassign_adapter file. The list of adapters that have
been assigned can be viewed by displaying the contents of the
adapters file.
For example, to assign adapter 0xad to mediated matrix device
$uuid:
echo ad > assign_adapter
To unassign adapter 0xad:
echo ad > unassign_adapter
To see the list of adapters assigned:
cat adapters
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/ap-config.h | 13 +++
drivers/s390/crypto/vfio_ap_matrix_ops.c | 147 ++++++++++++++++++++++++++++++
2 files changed, 160 insertions(+), 0 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_matrix_ops.c b/drivers/s390/crypto/vfio_ap_matrix_ops.c
index 7d01f18..e4b1236 100644
--- a/drivers/s390/crypto/vfio_ap_matrix_ops.c
+++ b/drivers/s390/crypto/vfio_ap_matrix_ops.c
@@ -23,6 +23,7 @@
struct ap_matrix_mdev {
struct mdev_device *mdev;
struct list_head node;
+ struct ap_config_masks masks;
};
struct ap_matrix *matrix;
@@ -136,9 +137,155 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
NULL,
};
+static int ap_matrix_id_is_xnum(char *id)
+{
+ size_t i;
+
+ for (i = 0; i < strlen(id); i++) {
+ if (!isxdigit(id[i]))
+ return 0;
+ }
+
+ return 1;
+}
This feels like something for which an utility function should already
exist...
See comment below
+
+static int ap_matrix_parse_id(const char *buf, unsigned int *id)
+{
+ int ret;
+ char *bufcpy;
+ char *id_str;
+
+ if ((strlen(buf) == 0) || (*buf == '\n')) {
+ pr_err("%s: input buffer '%s' contains no valid hex values",
+ VFIO_AP_MATRIX_MODULE_NAME, buf);
+ return -EINVAL;
+ }
+
+ bufcpy = kzalloc(strlen(buf) + 1, GFP_KERNEL);
+ if (!bufcpy)
+ return -ENOMEM;
+
+ strcpy(bufcpy, buf);
+ id_str = strim(bufcpy);
+
+ if (!ap_matrix_id_is_xnum(id_str)) {
+ pr_err("%s: input id '%s' contains an invalid hex value '%s'",
+ VFIO_AP_MATRIX_MODULE_NAME, buf, id_str);
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = kstrtouint (id_str, 16, id);
+ if (ret || (*id >= AP_MATRIX_MAX_MASK_BITS)) {
+ pr_err("%s: input id '%s' is not a value from 0 to %x",
+ VFIO_AP_MATRIX_MODULE_NAME, buf,
+ AP_MATRIX_MAX_MASK_BITS);
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = 0;
+
+done:
+ kfree(bufcpy);
+ return ret;
+}
Similarly, I suspect you are not the first person with similar parsing
needs.
I am going to remove this function
+
+static ssize_t ap_matrix_adapters_assign(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned int apid;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ ret = ap_matrix_parse_id(buf, &apid);
I'm going to replace this with a call to kstrtouint (buf, 0, &apid). This
will allow the user to enter the adapter ID string using conventional
semantics - e.g., 71 or 0x47 - and the function will determine if the
value is valid.
+ if (ret)
+ return ret;
+
+ set_bit_inv((unsigned long)apid,
+ (unsigned long *)matrix_mdev->masks.apm);
Probably needs a comment regarding byte order of the masks somewhere.
Okay
+
+ return count;
+}
+static DEVICE_ATTR(assign_adapter, 0644, NULL, ap_matrix_adapters_assign);