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

Cédric Le Goater
2023-05-31T13:08:27Z

On 5/31/23 00:35, Tony Krowiak wrote:
> 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>

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.

> ---
> 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);