Messages in this thread Patch in this message | | | Subject | Re: [PATCH] s390: protvirt: virtio: Refuse device without IOMMU | From | Pierre Morel <> | Date | Wed, 10 Jun 2020 16:37:55 +0200 |
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On 2020-06-10 15:24, Cornelia Huck wrote: > On Wed, 10 Jun 2020 15:11:51 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> Protected Virtualisation protects the memory of the guest and >> do not allow a the host to access all of its memory. >> >> Let's refuse a VIRTIO device which does not use IOMMU >> protected access. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> drivers/s390/virtio/virtio_ccw.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c >> index 5730572b52cd..06ffbc96587a 100644 >> --- a/drivers/s390/virtio/virtio_ccw.c >> +++ b/drivers/s390/virtio/virtio_ccw.c >> @@ -986,6 +986,11 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) >> if (!ccw) >> return; >> >> + /* Protected Virtualisation guest needs IOMMU */ >> + if (is_prot_virt_guest() && >> + !__virtio_test_bit(vdev, VIRTIO_F_IOMMU_PLATFORM)) >> + status &= ~VIRTIO_CONFIG_S_FEATURES_OK; >> + > > set_status seems like an odd place to look at features; shouldn't that > rather be done in finalize_features?
Right, looks better to me too. What about:
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index 06ffbc96587a..227676297ea0 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -833,6 +833,11 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev) ret = -ENOMEM; goto out_free; } + + if (is_prot_virt_guest() && + !__virtio_test_bit(vdev, VIRTIO_F_IOMMU_PLATFORM)) + return -EIO; + /* Give virtio_ring a chance to accept features. */ vring_transport_features(vdev);
Thanks,
Regards, Pierre
-- Pierre Morel IBM Lab Boeblingen
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