From: Tony Krowiak <akrowiak@linux.ibm.com>
To: pmorel@linux.ibm.com, 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
Subject: Re: [PATCH v6 3/7] s390: ap: setup relation betwen KVM and mediated device
Date: Thu, 28 Mar 2019 13:25:35 -0400 [thread overview]
Message-ID: <eaac369f-132b-b83f-fa14-8749819388ba@linux.ibm.com> (raw)
In-Reply-To: <3cd496d0-3eec-78e8-9ea5-4d62fe0cff1c@linux.ibm.com>
On 3/28/19 12:27 PM, Pierre Morel wrote:
> On 28/03/2019 17:12, Tony Krowiak wrote:
>> On 3/22/19 10:43 AM, Pierre Morel wrote:
>>> When the mediated device is open we setup the relation with KVM unset it
>>> when the mediated device is released.
>>
>> s/open we setup/open, we set up/
>> s/with KVM unset/with KVM and unset/
>>
>>>
>>> We lock the matrix mediated device to avoid any change until the
>>> open is done.
>>> We make sure that KVM is present when opening the mediated device
>>> otherwise we return an error.
>>
>> s/mediated device/mediated device,/
>>
>>>
>>> Increase kvm's refcount to ensure the KVM structures are still available
>>> during the use of the mediated device by the guest.
>>>
>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>> ---
>>> drivers/s390/crypto/vfio_ap_ops.c | 143
>>> +++++++++++++++++++++-----------------
>>> 1 file changed, 79 insertions(+), 64 deletions(-)
>>>
>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
>>> b/drivers/s390/crypto/vfio_ap_ops.c
>>> index 77f7bac..bdb36e0 100644
>>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>>> @@ -787,74 +787,24 @@ static const struct attribute_group
>>> *vfio_ap_mdev_attr_groups[] = {
>>> NULL
>>> };
>>> -/**
>>> - * vfio_ap_mdev_set_kvm
>>> - *
>>> - * @matrix_mdev: a mediated matrix device
>>> - * @kvm: reference to KVM instance
>>> - *
>>> - * Verifies no other mediated matrix device has @kvm and sets a
>>> reference to
>>> - * it in @matrix_mdev->kvm.
>>> - *
>>> - * Return 0 if no other mediated matrix device has a reference to @kvm;
>>> - * otherwise, returns an -EPERM.
>>> - */
>>> -static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
>>> - struct kvm *kvm)
>>> -{
>>> - struct ap_matrix_mdev *m;
>>> -
>>> - mutex_lock(&matrix_dev->lock);
>>> -
>>> - list_for_each_entry(m, &matrix_dev->mdev_list, node) {
>>> - if ((m != matrix_mdev) && (m->kvm == kvm)) {
>>> - mutex_unlock(&matrix_dev->lock);
>>> - return -EPERM;
>>> - }
>>> - }
>>> -
>>> - matrix_mdev->kvm = kvm;
>>> - mutex_unlock(&matrix_dev->lock);
>>> -
>>> - return 0;
>>> -}
>>> -
>>> static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
>>> unsigned long action, void *data)
>>> {
>>> - int ret;
>>> struct ap_matrix_mdev *matrix_mdev;
>>> if (action != VFIO_GROUP_NOTIFY_SET_KVM)
>>> return NOTIFY_OK;
>>> matrix_mdev = container_of(nb, struct ap_matrix_mdev,
>>> group_notifier);
>>> -
>>> - if (!data) {
>>> - matrix_mdev->kvm = NULL;
>>> - return NOTIFY_OK;
>>> - }
>>> -
>>> - ret = vfio_ap_mdev_set_kvm(matrix_mdev, data);
>>> - if (ret)
>>> - return NOTIFY_DONE;
>>> -
>>> - /* If there is no CRYCB pointer, then we can't copy the masks */
>>> - if (!matrix_mdev->kvm->arch.crypto.crycbd)
>>> - return NOTIFY_DONE;
>>> -
>>> - kvm_arch_crypto_set_masks(matrix_mdev->kvm,
>>> matrix_mdev->matrix.apm,
>>> - matrix_mdev->matrix.aqm,
>>> - matrix_mdev->matrix.adm);
>>> + matrix_mdev->kvm = data;
>>> return NOTIFY_OK;
>>> }
>>> -static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
>>> +static int vfio_ap_mdev_reset_queues(struct ap_matrix_mdev
>>> *matrix_mdev)
>>> {
>>> int ret;
>>> int rc = 0;
>>> - struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
>>> struct vfio_ap_queue *q;
>>> list_for_each_entry(q, &matrix_mdev->qlist, list) {
>>> @@ -871,41 +821,106 @@ static int vfio_ap_mdev_reset_queues(struct
>>> mdev_device *mdev)
>>> return rc;
>>> }
>>> +/**
>>> + * vfio_ap_mdev_set_kvm
>>> + *
>>> + * @matrix_mdev: a mediated matrix device
>>> + *
>>> + * - Verifies that the hook is free and install the PQAP hook
>>> + * - Copy the matrix masks inside the CRYCB
>>> + * - Increment the KVM rerference count
>>> + *
>>> + * Return 0 if no other mediated matrix device has a reference to @kvm;
>>> + * otherwise, returns an -EPERM.
>>> + */
>>> +static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev)
>>> +{
>>> + if (matrix_mdev->kvm->arch.crypto.pqap_hook)
>>> + return -EPERM;
>>
>> How would this happen; in other words, why are we checking this?
>
> I check this to verify that no other AP mediated device is already in
> use by this VM.
Maybe you should insert a comment to that effect.
>
> Regards,
> Pierre
>
>
>
next prev parent reply other threads:[~2019-03-28 17:25 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 14:43 [PATCH v6 0/7] vfio: ap: AP Queue Interrupt Control Pierre Morel
2019-03-22 14:43 ` [PATCH v6 1/7] s390: ap: kvm: add PQAP interception for AQIC Pierre Morel
2019-03-26 18:57 ` Tony Krowiak
2019-03-27 16:06 ` Tony Krowiak
2019-03-28 12:43 ` Pierre Morel
2019-03-28 15:24 ` Tony Krowiak
2019-03-28 16:12 ` Tony Krowiak
2019-03-29 8:52 ` Pierre Morel
2019-03-29 13:02 ` Tony Krowiak
2019-03-22 14:43 ` [PATCH v6 2/7] s390: ap: new vfio_ap_queue structure Pierre Morel
2019-03-25 8:05 ` Harald Freudenberger
2019-03-28 13:12 ` Pierre Morel
2019-03-26 20:45 ` Tony Krowiak
2019-03-27 11:00 ` Harald Freudenberger
2019-03-28 12:53 ` Pierre Morel
2019-03-28 13:06 ` Pierre Morel
2019-03-28 15:32 ` Tony Krowiak
2019-03-28 16:06 ` Pierre Morel
2019-04-02 12:47 ` Pierre Morel
2019-03-22 14:43 ` [PATCH v6 3/7] s390: ap: setup relation betwen KVM and mediated device Pierre Morel
2019-03-28 16:12 ` Tony Krowiak
2019-03-28 16:27 ` Pierre Morel
2019-03-28 17:25 ` Tony Krowiak [this message]
2019-03-29 8:58 ` Pierre Morel
2019-03-29 13:06 ` Tony Krowiak
2019-03-22 14:43 ` [PATCH v6 4/7] vfio: ap: register IOMMU VFIO notifier Pierre Morel
2019-03-28 20:46 ` Tony Krowiak
2019-03-29 9:31 ` Pierre Morel
2019-03-29 13:14 ` Tony Krowiak
2019-03-22 14:43 ` [PATCH v6 5/7] s390: ap: implement PAPQ AQIC interception in kernel Pierre Morel
2019-03-22 14:43 ` [PATCH v6 6/7] s390: ap: Cleanup on removing the AP device Pierre Morel
2019-03-22 14:43 ` [PATCH v6 7/7] s390: ap: kvm: Enable PQAP/AQIC facility for the guest Pierre Morel
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