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authorJiang Yi <giangyi@amazon.com>2019-11-27 17:49:10 +0100
committerAlex Williamson <alex.williamson@redhat.com>2019-12-02 14:34:41 -0700
commitd567fb8819162099035e546b11a736e29c2af0ea (patch)
tree7473979e80e7723a93d7be8efa512c90d4c19030 /drivers
parent4f5cafb5cb8471e54afdc9054d973535614f7675 (diff)
downloadlinux-d567fb8819162099035e546b11a736e29c2af0ea.tar.bz2
vfio/pci: call irq_bypass_unregister_producer() before freeing irq
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>
Diffstat (limited to 'drivers')
-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;