On 3/17/21 7:17 PM, Halil Pasic wrote:
On Wed, 10 Mar 2021 10:05:59 -0500 Tony Krowiak akrowiak@linux.ibm.com wrote:
ret = vfio_ap_mdev_reset_queues(mdev);
matrix_mdev = mdev_get_drvdata(mdev);Is it guaranteed that matrix_mdev can't be NULL here? If yes, please remind me of the mechanism that ensures this.
/** 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 == false,mutex_unlock(&matrix_dev->lock),mutex_lock(&matrix_dev->lock));if (matrix_mdev->kvm)ret = vfio_ap_mdev_reset_queues(mdev);elseret = -ENODEV;Didn't we agree to make the call to vfio_ap_mdev_reset_queues() unconditional again (for reference please take look at Message-ID: 64afa72c-2d6a-2ca1-e576-34e15fa579ed@linux.ibm.com)?
How about this:
static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev, unsigned int cmd, unsigned long arg) { int ret = 0; struct ap_matrix_mdev *matrix_mdev;
... case VFIO_DEVICE_RESET: matrix_mdev = mdev_get_drvdata(mdev); WARN(!matrix_mdev, "Driver data missing from mdev!!");
if (matrix_mdev) { /* * 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 == false, mutex_unlock(&matrix_dev->lock), mutex_lock(&matrix_dev->lock));
ret = vfio_ap_mdev_reset_queues(mdev); } break; ...
return ret; }
Regards, Halil