matrix_mdev = container_of(vcpu->kvm->arch.crypto.pqap_hook,
struct ap_matrix_mdev, pqap_hook);
+ /*
+ * If the KVM pointer is in the process of being set, wait until the
+ * process has completed.
+ */
+ wait_event_cmd(matrix_mdev->wait_for_kvm,
+ !matrix_mdev->kvm_busy,
+ mutex_unlock(&matrix_dev->lock),
+ mutex_lock(&matrix_dev->lock));
+
+ /* If the there is no guest using the mdev, there is nothing to do */
+ if (!matrix_mdev->kvm)
+ goto out_unlock;
+
q = vfio_ap_get_queue(matrix_mdev, apqn);
if (!q)
goto out_unlock;
matrix_mdev->mdev = mdev;
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
+ init_waitqueue_head(&matrix_mdev->wait_for_kvm);
mdev_set_drvdata(mdev, matrix_mdev);
matrix_mdev->pqap_hook.hook = handle_pqap;
matrix_mdev->pqap_hook.owner = THIS_MODULE;
{
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
- if (matrix_mdev->kvm)
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * un-assignment of control domain.
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ mutex_unlock(&matrix_dev->lock);
return -EBUSY;
+ }
- mutex_lock(&matrix_dev->lock);
vfio_ap_mdev_reset_queues(mdev);
list_del(&matrix_mdev->node);
- mutex_unlock(&matrix_dev->lock);
-
kfree(matrix_mdev);
mdev_set_drvdata(mdev, NULL);
atomic_inc(&matrix_dev->available_instances);
+ mutex_unlock(&matrix_dev->lock);
return 0;
}
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * un-assignment of adapter
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &apid);
if (ret)
- return ret;
+ goto done;
- if (apid > matrix_mdev->matrix.apm_max)
- return -ENODEV;
+ if (apid > matrix_mdev->matrix.apm_max) {
+ ret = -ENODEV;
+ goto done;
+ }
/*
* Set the bit in the AP mask (APM) corresponding to the AP adapter
* number (APID). The bits in the mask, from most significant to least
* significant bit, correspond to APIDs 0-255.
*/
- mutex_lock(&matrix_dev->lock);
-
ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
if (ret)
goto done;
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * un-assignment of adapter
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &apid);
if (ret)
- return ret;
+ goto done;
- if (apid > matrix_mdev->matrix.apm_max)
- return -ENODEV;
+ if (apid > matrix_mdev->matrix.apm_max) {
+ ret = -ENODEV;
+ goto done;
+ }
- mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+ ret = count;
+done:
mutex_unlock(&matrix_dev->lock);
-
- return count;
+ return ret;
}
static DEVICE_ATTR_WO(unassign_adapter);
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * assignment of domain
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &apqi);
if (ret)
- return ret;
- if (apqi > max_apqi)
- return -ENODEV;
-
- mutex_lock(&matrix_dev->lock);
+ goto done;
+ if (apqi > max_apqi) {
+ ret = -ENODEV;
+ goto done;
+ }
ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi);
if (ret)
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * un-assignment of domain
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &apqi);
if (ret)
- return ret;
+ goto done;
- if (apqi > matrix_mdev->matrix.aqm_max)
- return -ENODEV;
+ if (apqi > matrix_mdev->matrix.aqm_max) {
+ ret = -ENODEV;
+ goto done;
+ }
- mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
- mutex_unlock(&matrix_dev->lock);
+ ret = count;
- return count;
+done:
+ mutex_unlock(&matrix_dev->lock);
+ return ret;
}
static DEVICE_ATTR_WO(unassign_domain);
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * assignment of control domain.
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &id);
if (ret)
- return ret;
+ goto done;
- if (id > matrix_mdev->matrix.adm_max)
- return -ENODEV;
+ if (id > matrix_mdev->matrix.adm_max) {
+ ret = -ENODEV;
+ goto done;
+ }
/* 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.
*/
- mutex_lock(&matrix_dev->lock);
set_bit_inv(id, matrix_mdev->matrix.adm);
+ ret = count;
+done:
mutex_unlock(&matrix_dev->lock);
-
- return count;
+ return ret;
}
static DEVICE_ATTR_WO(assign_control_domain);
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;
+ mutex_lock(&matrix_dev->lock);
+
+ /*
+ * If the KVM pointer is in flux or the guest is running, disallow
+ * un-assignment of control domain.
+ */
+ if (matrix_mdev->kvm_busy || matrix_mdev->kvm) {
+ ret = -EBUSY;
+ goto done;
+ }
ret = kstrtoul(buf, 0, &domid);
if (ret)
- return ret;
- if (domid > max_domid)
- return -ENODEV;
+ goto done;
+ if (domid > max_domid) {
+ ret = -ENODEV;
+ goto done;
+ }
- mutex_lock(&matrix_dev->lock);
clear_bit_inv(domid, matrix_mdev->matrix.adm);
+ ret = count;
+done:
mutex_unlock(&matrix_dev->lock);
-
- return count;
+ return ret;
}
static DEVICE_ATTR_WO(unassign_control_domain);
* @matrix_mdev: a mediated matrix device
* @kvm: reference to KVM instance
*
- * Verifies no other mediated matrix device has @kvm and sets a reference to
- * it in @matrix_mdev->kvm.
+ * Sets all data for @matrix_mdev that are needed to manage AP resources
+ * for the guest whose state is represented by @kvm.
+ *
+ * Note: The matrix_dev->lock must be taken prior to calling
+ * this function; however, the lock will be temporarily released while the
+ * guest's AP configuration is set to avoid a potential lockdep splat.
+ * The kvm->lock is taken to set the guest's AP configuration which, under
+ * certain circumstances, will result in a circular lock dependency if this is
+ * done under the @matrix_mdev->lock.
*
* Return 0 if no other mediated matrix device has a reference to @kvm;
* otherwise, returns an -EPERM.
{
struct ap_matrix_mdev *m;
- list_for_each_entry(m, &matrix_dev->mdev_list, node) {
- if ((m != matrix_mdev) && (m->kvm == kvm))
- return -EPERM;
- }
+ if (kvm->arch.crypto.crycbd) {
+ list_for_each_entry(m, &matrix_dev->mdev_list, node) {
+ if (m != matrix_mdev && m->kvm == kvm)
+ return -EPERM;
+ }
- matrix_mdev->kvm = kvm;
- kvm_get_kvm(kvm);
- kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
+ kvm_get_kvm(kvm);
+ matrix_mdev->kvm_busy = true;
+ mutex_unlock(&matrix_dev->lock);
+ kvm_arch_crypto_set_masks(kvm,
+ matrix_mdev->matrix.apm,
+ matrix_mdev->matrix.aqm,
+ matrix_mdev->matrix.adm);
+ mutex_lock(&matrix_dev->lock);
+ kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
+ matrix_mdev->kvm = kvm;
+ matrix_mdev->kvm_busy = false;
+ wake_up_all(&matrix_mdev->wait_for_kvm);
+ }
return 0;
}
return NOTIFY_DONE;
}
+/**
+ * vfio_ap_mdev_unset_kvm
+ *
+ * @matrix_mdev: a matrix mediated device
+ *
+ * Performs clean-up of resources no longer needed by @matrix_mdev.
+ *
+ * Note: The matrix_dev->lock must be taken prior to calling
+ * this function; however, the lock will be temporarily released while the
+ * guest's AP configuration is cleared to avoid a potential lockdep splat.
+ * The kvm->lock is taken to clear the guest's AP configuration which, under
+ * certain circumstances, will result in a circular lock dependency if this is
+ * done under the @matrix_mdev->lock.
+ *
+ */
static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
{
- kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
- matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
- vfio_ap_mdev_reset_queues(matrix_mdev->mdev);
- kvm_put_kvm(matrix_mdev->kvm);
- matrix_mdev->kvm = NULL;
+ /*
+ * If the KVM pointer is in the process of being set, wait until the
+ * process has completed.
+ */
+ wait_event_cmd(matrix_mdev->wait_for_kvm,
+ !matrix_mdev->kvm_busy,
+ mutex_unlock(&matrix_dev->lock),
+ mutex_lock(&matrix_dev->lock));
+
+ if (matrix_mdev->kvm) {
+ matrix_mdev->kvm_busy = true;
+ mutex_unlock(&matrix_dev->lock);
+ kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+ mutex_lock(&matrix_dev->lock);
+ vfio_ap_mdev_reset_queues(matrix_mdev->mdev);
+ matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
+ kvm_put_kvm(matrix_mdev->kvm);
+ matrix_mdev->kvm = NULL;
+ matrix_mdev->kvm_busy = false;
+ wake_up_all(&matrix_mdev->wait_for_kvm);
+ }
}
static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
- int ret, notify_rc = NOTIFY_OK;
+ int notify_rc = NOTIFY_OK;
struct ap_matrix_mdev *matrix_mdev;
if (action != VFIO_GROUP_NOTIFY_SET_KVM)
return NOTIFY_OK;
- matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
mutex_lock(&matrix_dev->lock);
+ matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
- if (!data) {
- if (matrix_mdev->kvm)
- vfio_ap_mdev_unset_kvm(matrix_mdev);
- goto notify_done;
- }
-
- ret = vfio_ap_mdev_set_kvm(matrix_mdev, data);
- if (ret) {
- notify_rc = NOTIFY_DONE;
- goto notify_done;
- }
-
- /* If there is no CRYCB pointer, then we can't copy the masks */
- if (!matrix_mdev->kvm->arch.crypto.crycbd) {
+ if (!data)
+ vfio_ap_mdev_unset_kvm(matrix_mdev);
+ else if (vfio_ap_mdev_set_kvm(matrix_mdev, data))
notify_rc = NOTIFY_DONE;
- goto notify_done;
- }
-
- kvm_arch_crypto_set_masks(matrix_mdev->kvm, matrix_mdev->matrix.apm,
- matrix_mdev->matrix.aqm,
- matrix_mdev->matrix.adm);
-notify_done:
mutex_unlock(&matrix_dev->lock);
+
return notify_rc;
}
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
mutex_lock(&matrix_dev->lock);
- if (matrix_mdev->kvm)
- vfio_ap_mdev_unset_kvm(matrix_mdev);
+ vfio_ap_mdev_unset_kvm(matrix_mdev);
mutex_unlock(&matrix_dev->lock);
vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
unsigned int cmd, unsigned long arg)
{
int ret;
+ struct ap_matrix_mdev *matrix_mdev;
mutex_lock(&matrix_dev->lock);
switch (cmd) {
ret = vfio_ap_mdev_get_device_info(arg);
break;
case VFIO_DEVICE_RESET:
+ matrix_mdev = mdev_get_drvdata(mdev);
+ if (WARN(!matrix_mdev, "Driver data missing from mdev!!")) {
+ ret = -EINVAL;
+ break;
+ }
+
+ /*
+ * If the KVM pointer is in the process of being set, wait until
+ * the process has completed.
+ */
+ wait_event_cmd(matrix_mdev->wait_for_kvm,
+ !matrix_mdev->kvm_busy,
+ mutex_unlock(&matrix_dev->lock),
+ mutex_lock(&matrix_dev->lock));
+
ret = vfio_ap_mdev_reset_queues(mdev);
break;
default: