On Fri, 22 Feb 2019 16:29:56 +0100 Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote: > We need to associate the ap_vfio_queue, which will hold the > per queue information for interrupt with a matrix mediated device > which hold the configuration and the way to the CRYCB. [..] > +static int vfio_ap_get_all_domains(struct ap_matrix_mdev *matrix_mdev, int apid) > +{ > + int apqi, apqn; > + int ret = 0; > + struct vfio_ap_queue *q; > + struct list_head q_list; > + > + INIT_LIST_HEAD(&q_list); > + > + for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS) { > + apqn = AP_MKQID(apid, apqi); > + q = vfio_ap_get_queue(apqn, &matrix_dev->free_list); > + if (!q) { > + ret = -EADDRNOTAVAIL; > + goto rewind; > + } > + if (q->matrix_mdev) { > + ret = -EADDRINUSE; You tried to get the q from matrix_dev->free_list thus modulo races q->matrix_mdev should be 0. This change breaks the error codes in a sense that it becomes impossible to provoke EADDRINUSE (the proper error code for taken by another matrix_mdev). > + goto rewind; > + } > + list_move(&q->list, &q_list); > + } > + move_and_set(&q_list, &matrix_mdev->qlist, matrix_mdev); > return 0; > +rewind: > + move_and_set(&q_list, &matrix_dev->free_list, NULL); > + return ret; > } > - > /** > - * vfio_ap_mdev_verify_no_sharing > + * vfio_ap_get_all_cards: > * > - * Verifies that the APQNs derived from the cross product of the AP adapter IDs > - * and AP queue indexes comprising the AP matrix are not configured for another > - * mediated device. AP queue sharing is not allowed. > + * @matrix_mdev: the matrix mediated device for which we want to associate > + * all available queues with a given apqi. > + * @apqi: The apqi which associated with all defined APID of the > + * mediated device will define a AP queue. > * > - * @matrix_mdev: the mediated matrix device > + * We define a local list to put all queues we find on the matrix device > + * free list when associating the apqi with all already defined apid for > + * this matrix mediated device. > * > - * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE. > + * If we can get all the devices we roll them to the mediated device list > + * If we get errors we unroll them to the free list. > */ > -static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev) > +static int vfio_ap_get_all_cards(struct ap_matrix_mdev *matrix_mdev, int apqi) > { > - struct ap_matrix_mdev *lstdev; > - DECLARE_BITMAP(apm, AP_DEVICES); > - DECLARE_BITMAP(aqm, AP_DOMAINS); > - > - list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) { > - if (matrix_mdev == lstdev) > - continue; > - > - memset(apm, 0, sizeof(apm)); > - memset(aqm, 0, sizeof(aqm)); > - > - /* > - * We work on full longs, as we can only exclude the leftover > - * bits in non-inverse order. The leftover is all zeros. > - */ > - if (!bitmap_and(apm, matrix_mdev->matrix.apm, > - lstdev->matrix.apm, AP_DEVICES)) > - continue; > - > - if (!bitmap_and(aqm, matrix_mdev->matrix.aqm, > - lstdev->matrix.aqm, AP_DOMAINS)) > - continue; > - > - return -EADDRINUSE; > + int apid, apqn; > + int ret = 0; > + struct vfio_ap_queue *q; > + struct list_head q_list; > + struct ap_matrix_mdev *tmp = NULL; > + > + INIT_LIST_HEAD(&q_list); > + > + for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) { > + apqn = AP_MKQID(apid, apqi); > + q = vfio_ap_get_queue(apqn, &matrix_dev->free_list); > + if (!q) { > + ret = -EADDRNOTAVAIL; > + goto rewind; > + } > + if (q->matrix_mdev) { > + ret = -EADDRINUSE; Same here! Regards, Halil > + goto rewind; > + } > + list_move(&q->list, &q_list); > } [..]