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authorJiang Yi <giangyi@amazon.com>2019-11-27 17:49:10 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-12-21 11:04:48 +0100
commit6344beb64054d8b9204b4167a0ae1f85439548a7 (patch)
tree0d913a0f68ba8d525143019cb8b12b85878a04c1
parentf3362ea64bd352373765e4353e568be051ad2bf7 (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.c2
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;