diff options
| author | Jiang Yi <giangyi@amazon.com> | 2019-11-27 17:49:10 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-21 11:04:48 +0100 |
| commit | 6344beb64054d8b9204b4167a0ae1f85439548a7 (patch) | |
| tree | 0d913a0f68ba8d525143019cb8b12b85878a04c1 | |
| parent | f3362ea64bd352373765e4353e568be051ad2bf7 (diff) | |
vfio/pci: call irq_bypass_unregister_producer() before freeing irq
commit d567fb8819162099035e546b11a736e29c2af0ea upstream.
Since irq_bypass_register_producer() is called after request_irq(), we
should do tear-down in reverse order: irq_bypass_unregister_producer()
then free_irq().
Specifically free_irq() may release resources required by the
irqbypass del_producer() callback. Notably an example provided by
Marc Zyngier on arm64 with GICv4 that he indicates has the potential
to wedge the hardware:
free_irq(irq)
__free_irq(irq)
irq_domain_deactivate_irq(irq)
its_irq_domain_deactivate()
[unmap the VLPI from the ITS]
kvm_arch_irq_bypass_del_producer(cons, prod)
kvm_vgic_v4_unset_forwarding(kvm, irq, ...)
its_unmap_vlpi(irq)
[Unmap the VLPI from the ITS (again), remap the original LPI]
Signed-off-by: Jiang Yi <giangyi@amazon.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: 6d7425f109d26 ("vfio: Register/unregister irq_bypass_producer")
Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
[aw: commit log]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_intrs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 3fa3f728fb39..2056f3f85f59 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -294,8 +294,8 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev, irq = pci_irq_vector(pdev, vector); if (vdev->ctx[vector].trigger) { - free_irq(irq, vdev->ctx[vector].trigger); irq_bypass_unregister_producer(&vdev->ctx[vector].producer); + free_irq(irq, vdev->ctx[vector].trigger); kfree(vdev->ctx[vector].name); eventfd_ctx_put(vdev->ctx[vector].trigger); vdev->ctx[vector].trigger = NULL; |