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 10:35:45 +0100 |
| commit | b71f6e98eaeda48e7456793a1484312188f6c71a (patch) | |
| tree | c5df6ff27549abc4a61f885e627452bf1a3c9175 /drivers/vfio | |
| parent | 0e798e73d58284ca7c60a247610cd61680796812 (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>
Diffstat (limited to 'drivers/vfio')
| -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 5c8f767b6368..f7d48661aa94 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -318,8 +318,8 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev, return -EINVAL; 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; |