From c7b6b705efe583964ceacb1fba66a0d06cba8325 Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Thu, 29 Jun 2023 16:40:38 +0800 Subject: [PATCH] vfio/pci: Fix a segfault in vfio_realize MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The kvm irqchip notifier is only registered if the device supports INTx, however it's unconditionally removed in vfio realize error path. If the assigned device does not support INTx, this will cause QEMU to crash when vfio realize fails. Change it to conditionally remove the notifier only if the notify hook is setup. Before fix: (qemu) device_add vfio-pci,host=81:11.1,id=vfio1,bus=root1,xres=1 Connection closed by foreign host. After fix: (qemu) device_add vfio-pci,host=81:11.1,id=vfio1,bus=root1,xres=1 Error: vfio 0000:81:11.1: xres and yres properties require display=on (qemu) Fixes: c5478fea27ac ("vfio/pci: Respond to KVM irqchip change notifier") Signed-off-by: Zhenzhong Duan Reviewed-by: Cédric Le Goater Reviewed-by: Joao Martins Signed-off-by: Cédric Le Goater (cherry picked from commit 357bd7932a136613d700ee8bc83e9165f059d1f7) Signed-off-by: Michael Tokarev --- hw/vfio/pci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 939dcc3d4a..63eda94af7 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3159,7 +3159,9 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) out_deregister: pci_device_set_intx_routing_notifier(&vdev->pdev, NULL); - kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier); + if (vdev->irqchip_change_notifier.notify) { + kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier); + } out_teardown: vfio_teardown_msi(vdev); vfio_bars_exit(vdev);