Message ID | 1558452877-27822-3-git-send-email-pmorel@linux.ibm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | vfio: ap: AP Queue Interrupt Control | expand |
On 21.05.19 17:34, Pierre Morel wrote: > To be able to use the VFIO interface to facilitate the > mediated device memory pinning/unpinning we need to register > a notifier for IOMMU. > > While we will start to pin one guest page for the interrupt indicator > byte, this is still ok with ballooning as this page will never be > used by the guest virtio-balloon driver. > So the pinned page will never be freed. And even a broken guest does > so, that would not impact the host as the original page is still > in control by vfio. > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> > --- > drivers/s390/crypto/vfio_ap_ops.c | 43 ++++++++++++++++++++++++++++++++++- > drivers/s390/crypto/vfio_ap_private.h | 2 ++ > 2 files changed, 44 insertions(+), 1 deletion(-) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index 900b9cf..e8e87bf 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -759,6 +759,35 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev, > return 0; > } > > +/* > + * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback > + * > + * @nb: The notifier block > + * @action: Action to be taken > + * @data: data associated with the request > + * > + * For an UNMAP request, unpin the guest IOVA (the NIB guest address we > + * pinned before). Other requests are ignored. > + * > + */ > +static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + struct ap_matrix_mdev *matrix_mdev; > + > + matrix_mdev = container_of(nb, struct ap_matrix_mdev, iommu_notifier); > + > + if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) { > + struct vfio_iommu_type1_dma_unmap *unmap = data; > + unsigned long g_pfn = unmap->iova >> PAGE_SHIFT; > + > + vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1); > + return NOTIFY_OK; > + } > + > + return NOTIFY_DONE; > +} > + > static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > unsigned long action, void *data) > { > @@ -858,7 +887,17 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) > return ret; > } > > - return 0; > + matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier; > + events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; > + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > + &events, &matrix_mdev->iommu_notifier); > + if (!ret) > + return ret; > + > + vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, > + &matrix_mdev->group_notifier); > + module_put(THIS_MODULE); > + return ret; > } > > static void vfio_ap_mdev_release(struct mdev_device *mdev) > @@ -869,6 +908,8 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) > kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > > vfio_ap_mdev_reset_queues(mdev); > + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > + &matrix_mdev->iommu_notifier); > vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, > &matrix_mdev->group_notifier); > matrix_mdev->kvm = NULL; > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index a910be1..18dcc4d 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -81,8 +81,10 @@ struct ap_matrix_mdev { > struct list_head node; > struct ap_matrix matrix; > struct notifier_block group_notifier; > + struct notifier_block iommu_notifier; > struct kvm *kvm; > struct kvm_s390_module_hook pqap_hook; > + struct mdev_device *mdev; > }; > > extern int vfio_ap_mdev_register(void); acked-by: Harald Freudenberger <freude@linux.ibm.com>
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 900b9cf..e8e87bf 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -759,6 +759,35 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev, return 0; } +/* + * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback + * + * @nb: The notifier block + * @action: Action to be taken + * @data: data associated with the request + * + * For an UNMAP request, unpin the guest IOVA (the NIB guest address we + * pinned before). Other requests are ignored. + * + */ +static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct ap_matrix_mdev *matrix_mdev; + + matrix_mdev = container_of(nb, struct ap_matrix_mdev, iommu_notifier); + + if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) { + struct vfio_iommu_type1_dma_unmap *unmap = data; + unsigned long g_pfn = unmap->iova >> PAGE_SHIFT; + + vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -858,7 +887,17 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) return ret; } - return 0; + matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier; + events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &events, &matrix_mdev->iommu_notifier); + if (!ret) + return ret; + + vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, + &matrix_mdev->group_notifier); + module_put(THIS_MODULE); + return ret; } static void vfio_ap_mdev_release(struct mdev_device *mdev) @@ -869,6 +908,8 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) kvm_arch_crypto_clear_masks(matrix_mdev->kvm); vfio_ap_mdev_reset_queues(mdev); + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &matrix_mdev->iommu_notifier); vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, &matrix_mdev->group_notifier); matrix_mdev->kvm = NULL; diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index a910be1..18dcc4d 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -81,8 +81,10 @@ struct ap_matrix_mdev { struct list_head node; struct ap_matrix matrix; struct notifier_block group_notifier; + struct notifier_block iommu_notifier; struct kvm *kvm; struct kvm_s390_module_hook pqap_hook; + struct mdev_device *mdev; }; extern int vfio_ap_mdev_register(void);