From: Alex Williamson alex.williamson@redhat.com
[ Upstream commit 852b1beecb6ff9326f7ca4bc0fe69ae860ebdb9e ]
The eventfd context is used as our irqbypass token, therefore if an eventfd is re-used, our token is the same. The irqbypass code will return an -EBUSY in this case, but we'll still attempt to unregister the producer, where if that duplicate token still exists, results in removing the wrong object. Clear the token of failed producers so that they harmlessly fall out when unregistered.
Fixes: 6d7425f109d2 ("vfio: Register/unregister irq_bypass_producer") Reported-by: guomin chen guomin_chen@sina.com Tested-by: guomin chen guomin_chen@sina.com Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/pci/vfio_pci_intrs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 1d9fb25929459..869dce5f134dd 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -352,11 +352,13 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev, vdev->ctx[vector].producer.token = trigger; vdev->ctx[vector].producer.irq = irq; ret = irq_bypass_register_producer(&vdev->ctx[vector].producer); - if (unlikely(ret)) + if (unlikely(ret)) { dev_info(&pdev->dev, "irq bypass producer (token %p) registration fails: %d\n", vdev->ctx[vector].producer.token, ret);
+ vdev->ctx[vector].producer.token = NULL; + } vdev->ctx[vector].trigger = trigger;
return 0;