From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v4 6/7] s390: ap: Cleanup on removing the AP device Date: Mon, 11 Mar 2019 09:31:02 +0100 Message-ID: <94904df0-42b6-51f8-6440-68722ef5419d@linux.ibm.com> References: <1550849400-27152-1-git-send-email-pmorel@linux.ibm.com> <1550849400-27152-7-git-send-email-pmorel@linux.ibm.com> <3956ad4c-55c9-e42c-4ab2-00ddae05b317@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: <3956ad4c-55c9-e42c-4ab2-00ddae05b317@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 08/03/2019 23:43, Tony Krowiak wrote: > On 2/22/19 10:29 AM, Pierre Morel wrote: >> When the device is remove, we must make sure to >> clear the interruption and reset the AP device. >> >> We also need to clear the CRYCB of the guest. >> >> Signed-off-by: Pierre Morel >> --- >>   drivers/s390/crypto/vfio_ap_drv.c     | 35 >> +++++++++++++++++++++++++++++++++++ >>   drivers/s390/crypto/vfio_ap_ops.c     |  3 ++- >>   drivers/s390/crypto/vfio_ap_private.h |  3 +++ >>   3 files changed, 40 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_drv.c >> b/drivers/s390/crypto/vfio_ap_drv.c >> index eca0ffc..e5d91ff 100644 >> --- a/drivers/s390/crypto/vfio_ap_drv.c >> +++ b/drivers/s390/crypto/vfio_ap_drv.c >> @@ -5,6 +5,7 @@ >>    * Copyright IBM Corp. 2018 >>    * >>    * Author(s): Tony Krowiak >> + *          Pierre Morel >>    */ >>   #include >> @@ -12,6 +13,8 @@ >>   #include >>   #include >>   #include >> +#include >> +#include >>   #include "vfio_ap_private.h" >>   #define VFIO_AP_ROOT_NAME "vfio_ap" >> @@ -61,6 +64,33 @@ static int vfio_ap_queue_dev_probe(struct ap_device >> *apdev) >>   } >>   /** >> + * vfio_ap_update_crycb >> + * @q: A pointer to the queue being removed >> + * >> + * We clear the APID of the queue, making this queue unusable for the >> guest. >> + * After this function we can reset the queue without to fear a race >> with >> + * the guest to access the queue again. >> + * We do not fear race with the host as we still get the device. >> + */ >> +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) >> +{ >> +    struct ap_matrix_mdev *matrix_mdev = q->matrix_mdev; >> + >> +    if (!matrix_mdev) >> +        return; >> + >> +    clear_bit_inv(AP_QID_CARD(q->apqn), matrix_mdev->matrix.apm); >> + >> +    if (!matrix_mdev->kvm) >> +        return; >> + >> +    kvm_arch_crypto_set_masks(matrix_mdev->kvm, >> +                  matrix_mdev->matrix.apm, >> +                  matrix_mdev->matrix.aqm, >> +                  matrix_mdev->matrix.adm); >> +} >> + >> +/** >>    * vfio_ap_queue_dev_remove: >>    * >>    * Free the associated vfio_ap_queue structure >> @@ -70,6 +100,11 @@ static void vfio_ap_queue_dev_remove(struct >> ap_device *apdev) >>       struct vfio_ap_queue *q; >>       q = dev_get_drvdata(&apdev->device); >> +    if (!q) >> +        return; >> + >> +    vfio_ap_update_crycb(q); >> +    vfio_ap_mdev_reset_queue(q); > > Since the bit corresponding to the APID is cleared in the > vfio_ap_update_crycb() above, shouldn't all queues on that > card also be reset? I do not think so. The remove function will be called in a loop for all queues by the bus. No need to clear all queues. > >>       list_del(&q->list); >>       kfree(q); >>   } >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c >> b/drivers/s390/crypto/vfio_ap_ops.c >> index 0196065..5b9bb33 100644 >> --- a/drivers/s390/crypto/vfio_ap_ops.c >> +++ b/drivers/s390/crypto/vfio_ap_ops.c >> @@ -59,6 +59,7 @@ int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) >>               if (retry <= 0) >>                   pr_warn("%s: queue 0x%04x not empty\n", >>                       __func__, q->apqn); >> +            vfio_ap_free_irq(q); > > Shouldn't this be done for the response codes that terminate this loop > such as those caught by the default case? I do not think so, the error code is returned and the caller may want to reset the queue again. I think that doing the free inside the call to reset is not right. I will investigate in this direction. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany