xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

vfio: ap: register IOMMU VFIO notifier

Browse Source 
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>
Acked-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Pierre Morel
2019-05-21 17:34:35 +02:00
committed by Vasily Gorbik
parent e5282de931
commit 62e358ce58
2 changed files with 44 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
drivers/s390/crypto/vfio_ap_ops.c
View File

@@ -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;