diff options
author | Alex Williamson <alex.williamson@redhat.com> | 2018-07-13 00:33:04 +0200 |
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committer | Alex Williamson <alex.williamson@redhat.com> | 2018-08-06 20:23:19 +0200 |
commit | 0dd0e297f0ec780b6b3484ba38b27d18c8ca7af9 (patch) | |
tree | 7ca25cc8284c0a53355f710582cc3b66f2f1905a /drivers | |
parent | vfio: Mark expected switch fall-throughs (diff) | |
download | linux-0dd0e297f0ec780b6b3484ba38b27d18c8ca7af9.tar.xz linux-0dd0e297f0ec780b6b3484ba38b27d18c8ca7af9.zip |
vfio-pci: Disable binding to PFs with SR-IOV enabled
We expect to receive PFs with SR-IOV disabled, however some host
drivers leave SR-IOV enabled at unbind. This puts us in a state where
we can potentially assign both the PF and the VF, leading to both
functionality as well as security concerns due to lack of managing the
SR-IOV state as well as vendor dependent isolation from the PF to VF.
If we were to attempt to actively disable SR-IOV on driver probe, we
risk VF bound drivers blocking, potentially risking live lock
scenarios. Therefore simply refuse to bind to PFs with SR-IOV enabled
with a warning message indicating the issue. Users can resolve this
by re-binding to the host driver and disabling SR-IOV before
attempting to use the device with vfio-pci.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 7fe2748ba101..9979d3ba9e52 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1193,6 +1193,19 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL) return -EINVAL; + /* + * Prevent binding to PFs with VFs enabled, this too easily allows + * userspace instance with VFs and PFs from the same device, which + * cannot work. Disabling SR-IOV here would initiate removing the + * VFs, which would unbind the driver, which is prone to blocking + * if that VF is also in use by vfio-pci. Just reject these PFs + * and let the user sort it out. + */ + if (pci_num_vf(pdev)) { + pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n"); + return -EBUSY; + } + group = vfio_iommu_group_get(&pdev->dev); if (!group) return -EINVAL; |