From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v4 3/7] s390: ap: associate a ap_vfio_queue and a matrix mdev Date: Wed, 27 Feb 2019 10:29:12 +0100 Message-ID: References: <1550849400-27152-1-git-send-email-pmorel@linux.ibm.com> <1550849400-27152-4-git-send-email-pmorel@linux.ibm.com> <0c109cf1-c5f0-9a8b-7729-2ce8bbe1dedd@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <0c109cf1-c5f0-9a8b-7729-2ce8bbe1dedd@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Tony Krowiak , borntraeger@de.ibm.com Cc: alex.williamson@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com List-ID: On 26/02/2019 19:14, Tony Krowiak wrote: > On 2/22/19 10:29 AM, Pierre Morel 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. >> >> Let's do this when assigning a APID or a APQI to the mediated device >> and clear the relation when unassigning. >> >> Queuing the devices on a list of free devices and testing the >> matrix_mdev pointer to the associated matrix allow us to know >> if the queue is associated to the matrix device and associated >> or not to a mediated device. >> >> When resetting an AP queue we must wait until there are no more >> messages in the message queue before considering the queue is really >> in a clean state. >> >> Let's do it and wait until the status response code indicate the >> queue is empty after issuing a PAPQ/ZAPQ instruction. >> >> Being at work on the reset function, let's simplify >> vfio_ap_mdev_reset_queue and vfio_ap_mdev_reset_queues by using the >> vfio_ap_queue structure as parameter. >> >> Signed-off-by: Pierre Morel >> --- >>   drivers/s390/crypto/vfio_ap_ops.c | 385 >> +++++++++++++++++++------------------- >>   1 file changed, 189 insertions(+), 196 deletions(-) ...snip... >> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) >> +{ >> +    struct ap_queue_status status; >> +    int retry = 20; >> + >> +    do { >> +        status = ap_zapq(q->apqn); >> +        switch (status.response_code) { >> +        case AP_RESPONSE_NORMAL: >> +            while (!status.queue_empty && retry--) { >> +                msleep(20); >> +                status = ap_tapq(q->apqn, NULL); >> +            } > > I am not sure the above is necessary. I have an email out to the author > of the architecture doc to verify. I do not know the question you asked but the documentation is very clear on the reset behavior: a queue is completely reseted only after the RC of reset/zapq is 0 and the queue_empty bit is set. > >> +            if (retry <= 0) >> +                pr_warn("%s: queue 0x%04x not empty\n", ...snip... >> + * @matrix_mdev: the matrix mediated device for which we want to >> associate >> + *         all available queues with a given apqi. >> + * @apid:     The apid which associated with all defined APQI of the >> + *         mediated device will define a AP queue. >>    * >> - * - If @data contains only an apid value, @data will be flagged as >> - *   reserved if the APID field in the AP queue device matches >> - * >> - * - If @data contains only an apqi value, @data will be flagged as >> - *   reserved if the APQI field in the AP queue device matches >> - * >> - * Returns 0 to indicate the input to function succeeded. Returns >> -EINVAL if >> - * @data does not contain either an apid or apqi. >> + * We remove the queue from the list of queues associated with the >> + * mediated device and put them back to the free list of the matrix >> + * device and clear the matrix_mdev pointer. >>    */ >> -static int vfio_ap_has_queue(struct device *dev, void *data) >> +static void vfio_ap_put_all_domains(struct ap_matrix_mdev *matrix_mdev, >> +                    int apid) > > I would prefer this be named: > >     vfio_ap_mdev_free_queues_with_apid() > > get/put is typically used to increment/decrement reference counters. > What you are doing in this function freeing all queues connected to > specified card. OK, I can change this function name and the further one you mentioned. > >>   { >> -    struct vfio_ap_queue_reserved *qres = data; >> -    struct ap_queue *ap_queue = to_ap_queue(dev); >> -    ap_qid_t qid; >> -    unsigned long id; >> +    int apqi, apqn; >> -    if (qres->apid && qres->apqi) { >> -        qid = AP_MKQID(*qres->apid, *qres->apqi); >> -        if (qid == ap_queue->qid) >> -            qres->reserved = true; >> -    } else if (qres->apid && !qres->apqi) { >> -        id = AP_QID_CARD(ap_queue->qid); >> -        if (id == *qres->apid) >> -            qres->reserved = true; >> -    } else if (!qres->apid && qres->apqi) { >> -        id = AP_QID_QUEUE(ap_queue->qid); >> -        if (id == *qres->apqi) >> -            qres->reserved = true; >> -    } else { >> -        return -EINVAL; >> +    for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS) { >> +        apqn = AP_MKQID(apid, apqi); >> +        vfio_ap_free_queue(apqn, matrix_mdev); >>       } > > Maybe you should clear the bit corresponding to apid from the APM here? I do not think so, this is pure list handling, the APM bit is already cleared in the unassign_adapter_store function. I only answered once for all comments on naming and bit mask but will treat them the same way. Thanks for comments. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany