Messages in this thread | | | Subject | Re: [PATCH v6 3/7] s390: ap: setup relation betwen KVM and mediated device | From | Pierre Morel <> | Date | Thu, 28 Mar 2019 17:27:41 +0100 |
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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.
Regards, Pierre
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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