lkml.org 
[lkml]   [2019]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/7] s390: vfio-ap: allow hot plug/unplug of AP resources using mdev device
Date
Let's allow adapters, domains and control domains to be assigned to or
unassigned from an AP matrix mdev device while it is in use by a guest.
When an adapter, domain or control domain is assigned to or unassigned
from an mdev device while a guest is using it, the guest's CRYCB will be
updated thus giving access to the resource assigned, or taking access away
from the resource unassigned for the guest.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 68 +++++++++++++++++++--------------------
1 file changed, 33 insertions(+), 35 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index cb3e4f7671be..cda1d216ee38 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -155,6 +155,24 @@ static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
return 0;
}

+/*
+ * vfio_ap_mdev_update_crycb
+ *
+ * @matrix_mdev: the mediated matrix device
+ *
+ * Updates the AP matrix in the guest's CRYCB from the masks configured for the
+ * mediated matrix device via its sysfs interfaces.
+ */
+static void vfio_ap_mdev_update_crycb(struct ap_matrix_mdev *matrix_mdev)
+{
+ if (matrix_mdev->kvm) {
+ kvm_arch_crypto_set_masks(matrix_mdev->kvm,
+ matrix_mdev->matrix.apm,
+ matrix_mdev->matrix.aqm,
+ matrix_mdev->matrix.adm);
+ }
+}
+
/**
* assign_adapter_store
*
@@ -196,10 +214,6 @@ static ssize_t assign_adapter_store(struct device *dev,
struct mdev_device *mdev = mdev_from_dev(dev);
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);

- /* If the guest is running, disallow assignment of adapter */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &apid);
if (ret)
return ret;
@@ -214,16 +228,12 @@ static ssize_t assign_adapter_store(struct device *dev,
*/
mutex_lock(&matrix_dev->lock);

- ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
- if (ret)
- goto done;
-
set_bit_inv(apid, matrix_mdev->matrix.apm);

ret = ap_apqn_in_matrix_owned_by_def_drv(matrix_mdev->matrix.apm,
matrix_mdev->matrix.aqm);

- /* If any APQN is reserved for used by the default drivers */
+ /* If any APQN is owned by the default drivers */
ret = (ret == 1) ? -EADDRNOTAVAIL : ret;
if (ret)
goto error;
@@ -232,6 +242,7 @@ static ssize_t assign_adapter_store(struct device *dev,
if (ret)
goto error;

+ vfio_ap_mdev_update_crycb(matrix_mdev);
ret = count;
goto done;

@@ -270,10 +281,6 @@ static ssize_t unassign_adapter_store(struct device *dev,
struct mdev_device *mdev = mdev_from_dev(dev);
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);

- /* If the guest is running, disallow un-assignment of adapter */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &apid);
if (ret)
return ret;
@@ -283,6 +290,7 @@ static ssize_t unassign_adapter_store(struct device *dev,

mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+ vfio_ap_mdev_update_crycb(matrix_mdev);
mutex_unlock(&matrix_dev->lock);

return count;
@@ -331,10 +339,6 @@ static ssize_t assign_domain_store(struct device *dev,
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
unsigned long max_apqi = matrix_mdev->matrix.aqm_max;

- /* If the guest is running, disallow assignment of domain */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &apqi);
if (ret)
return ret;
@@ -355,12 +359,13 @@ static ssize_t assign_domain_store(struct device *dev,

ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
if (ret)
- goto share_err;
+ goto error;

+ vfio_ap_mdev_update_crycb(matrix_mdev);
ret = count;
goto done;

-share_err:
+error:
clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
done:
mutex_unlock(&matrix_dev->lock);
@@ -396,10 +401,6 @@ static ssize_t unassign_domain_store(struct device *dev,
struct mdev_device *mdev = mdev_from_dev(dev);
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);

- /* If the guest is running, disallow un-assignment of domain */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &apqi);
if (ret)
return ret;
@@ -409,6 +410,7 @@ static ssize_t unassign_domain_store(struct device *dev,

mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
+ vfio_ap_mdev_update_crycb(matrix_mdev);
mutex_unlock(&matrix_dev->lock);

return count;
@@ -440,10 +442,6 @@ static ssize_t assign_control_domain_store(struct device *dev,
struct mdev_device *mdev = mdev_from_dev(dev);
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);

- /* If the guest is running, disallow assignment of control domain */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &id);
if (ret)
return ret;
@@ -451,13 +449,16 @@ static ssize_t assign_control_domain_store(struct device *dev,
if (id > matrix_mdev->matrix.adm_max)
return -ENODEV;

- /* Set the bit in the ADM (bitmask) corresponding to the AP control
- * domain number (id). The bits in the mask, from most significant to
- * least significant, correspond to IDs 0 up to the one less than the
- * number of control domains that can be assigned.
+ /*
+ * Set the bits in the ADM (bitmask) corresponding to the AP control
+ * domain numbers in dommask. The bits in the mask, from left to right,
+ * correspond to IDs 0 up to the one less than the number of control
+ * domains that can be assigned.
+ *
*/
mutex_lock(&matrix_dev->lock);
set_bit_inv(id, matrix_mdev->matrix.adm);
+ vfio_ap_mdev_update_crycb(matrix_mdev);
mutex_unlock(&matrix_dev->lock);

return count;
@@ -490,10 +491,6 @@ static ssize_t unassign_control_domain_store(struct device *dev,
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
unsigned long max_domid = matrix_mdev->matrix.adm_max;

- /* If the guest is running, disallow un-assignment of control domain */
- if (matrix_mdev->kvm)
- return -EBUSY;
-
ret = kstrtoul(buf, 0, &domid);
if (ret)
return ret;
@@ -502,6 +499,7 @@ static ssize_t unassign_control_domain_store(struct device *dev,

mutex_lock(&matrix_dev->lock);
clear_bit_inv(domid, matrix_mdev->matrix.adm);
+ vfio_ap_mdev_update_crycb(matrix_mdev);
mutex_unlock(&matrix_dev->lock);

return count;
--
2.7.4
\
 
 \ /
  Last update: 2019-04-11 23:05    [W:0.108 / U:0.488 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site