Messages in this thread | | | Subject | Re: [PATCH v6 2/7] s390: ap: new vfio_ap_queue structure | From | Tony Krowiak <> | Date | Thu, 28 Mar 2019 11:32:03 -0400 |
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On 3/28/19 9:06 AM, Pierre Morel wrote: > On 26/03/2019 21:45, Tony Krowiak wrote: >> On 3/22/19 10:43 AM, Pierre Morel wrote: >>> The AP interruptions are assigned on a queue basis and >>> the GISA structure is handled on a VM basis, so that >>> we need to add a structure we can retrieve from both side >> >> s/side/sides/ > OK > >> >>> holding the information we need to handle PQAP/AQIC interception >>> and setup the GISA. >> >> s/setup/set up/ > > OK > > ...snip... > >>> + >>> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) >>> +{ >>> + struct ap_queue_status status; >>> + int retry = 1; >>> + >>> + do { >>> + status = ap_zapq(q->apqn); >>> + switch (status.response_code) { >>> + case AP_RESPONSE_NORMAL: >>> + return 0; >>> + case AP_RESPONSE_RESET_IN_PROGRESS: >>> + case AP_RESPONSE_BUSY: >>> + msleep(20); >>> + break; >>> + default: >>> + /* things are really broken, give up */ >> >> I'm not sure things are necessarily broken. We could end up here if >> the AP is removed from the configuration via the SE or SCLP Deconfigure >> Adjunct Processor command. > > OK, but note that it is your original comment I just moved the function > here ;)
Yes, it is. I'm smarter now;)
> >> >>> + return -EIO; >>> + } >>> + } while (retry--); >>> + >>> + return -EBUSY; >>> +} >>> + >>> static void vfio_ap_matrix_init(struct ap_config_info *info, >>> struct ap_matrix *matrix) >>> { >>> @@ -45,6 +107,7 @@ static int vfio_ap_mdev_create(struct kobject >>> *kobj, struct mdev_device *mdev) >>> return -ENOMEM; >>> } >>> + INIT_LIST_HEAD(&matrix_mdev->qlist); >>> vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix); >>> mdev_set_drvdata(mdev, matrix_mdev); >>> mutex_lock(&matrix_dev->lock); >>> @@ -113,162 +176,189 @@ static struct attribute_group >>> *vfio_ap_mdev_type_groups[] = { >>> NULL, >>> }; >>> -struct vfio_ap_queue_reserved { >>> - unsigned long *apid; >>> - unsigned long *apqi; >>> - bool reserved; >>> -}; >>> +static void vfio_ap_free_queue(int apqn, struct ap_matrix_mdev >>> *matrix_mdev) >>> +{ >>> + struct vfio_ap_queue *q; >>> + >>> + q = vfio_ap_get_queue(apqn, &matrix_mdev->qlist); >>> + if (!q) >>> + return; >>> + q->matrix_mdev = NULL; >>> + vfio_ap_mdev_reset_queue(q); >> >> I'm wondering if it's necessary to reset the queue here. The only time >> a queue is used is when a guest using the mdev device is started. When >> that guest is terminated, the fd for the mdev device is /* Bits 41-47 must all be zeros */closed and the >> mdev device's release callback is invoked. The release callback resets >> the queues assigned to the mdev device. Is it really necessary to >> reset the queue again when it is unassigned even if there would have >> been no subsequent activity? > > Yes, it is necessary, the queue can be re-assigned to another guest later. > Release will only be called when unbinding the queue from the driver.
That is true, but if the queue is never used, there is nothing to reset.
> >> >>> + list_move(&q->list, &matrix_dev->free_list); >>> +} > > ...snip... > >>> + for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) { >>> + apqn = AP_MKQID(apid, apqi); >>> + q = vfio_ap_find_queue(apqn); >>> + if (!q) { >>> + ret = -EADDRNOTAVAIL; >>> + goto rewind; >>> + } >>> + if (q->matrix_mdev) { >> >> If somebody assigns the same domain a second time, the assignment will >> fail because the matrix_mdev will already have been associated with the >> queue. I don't think it is appropriate to fail the assignment if the > > It is usual to report a failure in the case the operation requested has > already be done. > But we can do as you want. Any other opinion? > >> q->matrix_mdev is the same as the input matrix_mdev. This should be >> changed to: >> >> if (q->matrix_mdev != matrix_mdev) > > You surely want to say: add this, not change to this. ;)
Yes
> >> > > Thanks for commenting, > > Regards, > Pierre > >
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