[PATCH 2/3] vfio: ap: realize the VFIO_DEVICE_SET_IRQS ioctl

Tony Krowiak
2023-05-30T22:35:50Z

Realize the VFIO_DEVICE_SET_IRQS ioctl to set an eventfd file descriptor
to be used by the vfio_ap device driver to signal a device request to
userspace.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 83 +++++++++++++++++++++++++++
drivers/s390/crypto/vfio_ap_private.h | 3 +
2 files changed, 86 insertions(+)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 35cd90eee937..44f159136891 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -716,6 +716,7 @@ static int vfio_ap_mdev_probe(struct mdev_device *mdev)
ret = vfio_register_emulated_iommu_dev(&matrix_mdev->vdev);
if (ret)
goto err_put_vdev;
+ matrix_mdev->req_trigger = NULL;
dev_set_drvdata(&mdev->dev, matrix_mdev);
mutex_lock(&matrix_dev->mdevs_lock);
list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
@@ -1780,6 +1781,85 @@ static ssize_t vfio_ap_get_irq_info(unsigned long arg)
return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
}

+static int vfio_ap_irq_set_init(struct vfio_irq_set *irq_set, unsigned long arg)
+{
+ int ret;
+ size_t data_size;
+ unsigned long minsz;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+
+ if (copy_from_user(irq_set, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ ret = vfio_set_irqs_validate_and_prepare(irq_set, 1, VFIO_AP_NUM_IRQS,
+ &data_size);
+ if (ret)
+ return ret;
+
+ if (!(irq_set->flags & VFIO_IRQ_SET_ACTION_TRIGGER))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int vfio_ap_set_request_irq(struct ap_matrix_mdev *matrix_mdev,
+ unsigned long arg)
+{
+ s32 fd;
+ void __user *data;
+ unsigned long minsz;
+ struct eventfd_ctx *req_trigger;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+ data = (void __user *)(arg + minsz);
+
+ if (get_user(fd, (s32 __user *)data))
+ return -EFAULT;
+
+ if (fd == -1) {
+ if (matrix_mdev->req_trigger)
+ eventfd_ctx_put(matrix_mdev->req_trigger);
+ matrix_mdev->req_trigger = NULL;
+ } else if (fd >= 0) {
+ req_trigger = eventfd_ctx_fdget(fd);
+ if (IS_ERR(req_trigger))
+ return PTR_ERR(req_trigger);
+
+ if (matrix_mdev->req_trigger)
+ eventfd_ctx_put(matrix_mdev->req_trigger);
+
+ matrix_mdev->req_trigger = req_trigger;
+ } else {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int vfio_ap_set_irqs(struct ap_matrix_mdev *matrix_mdev,
+ unsigned long arg)
+{
+ int ret;
+ struct vfio_irq_set irq_set;
+
+ ret = vfio_ap_irq_set_init(&irq_set, arg);
+ if (ret)
+ return ret;
+
+ switch (irq_set.flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ switch (irq_set.index) {
+ case VFIO_AP_REQ_IRQ_INDEX:
+ return vfio_ap_set_request_irq(matrix_mdev, arg);
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
static ssize_t vfio_ap_mdev_ioctl(struct vfio_device *vdev,
unsigned int cmd, unsigned long arg)
{
@@ -1798,6 +1878,9 @@ static ssize_t vfio_ap_mdev_ioctl(struct vfio_device *vdev,
case VFIO_DEVICE_GET_IRQ_INFO:
ret = vfio_ap_get_irq_info(arg);
break;
+ case VFIO_DEVICE_SET_IRQS:
+ ret = vfio_ap_set_irqs(matrix_mdev, arg);
+ break;
default:
ret = -EOPNOTSUPP;
break;
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 976a65f32e7d..4642bbdbd1b2 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -15,6 +15,7 @@
#include <linux/types.h>
#include <linux/mdev.h>
#include <linux/delay.h>
+#include <linux/eventfd.h>
#include <linux/mutex.h>
#include <linux/kvm_host.h>
#include <linux/vfio.h>
@@ -103,6 +104,7 @@ struct ap_queue_table {
* PQAP(AQIC) instruction.
* @mdev: the mediated device
* @qtable: table of queues (struct vfio_ap_queue) assigned to the mdev
+ * @req_trigger eventfd ctx for signaling userspace to return a device
* @apm_add: bitmap of APIDs added to the host's AP configuration
* @aqm_add: bitmap of APQIs added to the host's AP configuration
* @adm_add: bitmap of control domain numbers added to the host's AP
@@ -117,6 +119,7 @@ struct ap_matrix_mdev {
crypto_hook pqap_hook;
struct mdev_device *mdev;
struct ap_queue_table qtable;
+ struct eventfd_ctx *req_trigger;
DECLARE_BITMAP(apm_add, AP_DEVICES);
DECLARE_BITMAP(aqm_add, AP_DOMAINS);
DECLARE_BITMAP(adm_add, AP_DOMAINS);
--
2.31.1