On Wed, Sep 28, 2022 at 11:57:06AM +0800, Angus Chen wrote: > The background is that we use dpu in cloud computing,the arch is x86,80 > cores.We will have a lots of virtio devices,like 512 or more. > When we probe about 200 virtio_blk devices,it will fail and > the stack is print as follows: > > [25338.485128] virtio-pci 0000:b3:00.0: virtio_pci: leaving for legacy driver > [25338.496174] genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer) > [25338.503822] CPU: 20 PID: 5431 Comm: kworker/20:0 Kdump: loaded Tainted: G OE --------- - - 4.18.0-305.30.1.el8.x86_64 > [25338.516403] Hardware name: Inspur NF5280M5/YZMB-00882-10E, BIOS 4.1.21 08/25/2021 > [25338.523881] Workqueue: events work_for_cpu_fn > [25338.528235] Call Trace: > [25338.530687] dump_stack+0x5c/0x80 > [25338.534000] __setup_irq.cold.53+0x7c/0xd3 > [25338.538098] request_threaded_irq+0xf5/0x160 > [25338.542371] vp_find_vqs+0xc7/0x190 > [25338.545866] init_vq+0x17c/0x2e0 [virtio_blk] > [25338.550223] ? ncpus_cmp_func+0x10/0x10 > [25338.554061] virtblk_probe+0xe6/0x8a0 [virtio_blk] > [25338.558846] virtio_dev_probe+0x158/0x1f0 > [25338.562861] really_probe+0x255/0x4a0 > [25338.566524] ? __driver_attach_async_helper+0x90/0x90 > [25338.571567] driver_probe_device+0x49/0xc0 > [25338.575660] bus_for_each_drv+0x79/0xc0 > [25338.579499] __device_attach+0xdc/0x160 > [25338.583337] bus_probe_device+0x9d/0xb0 > [25338.587167] device_add+0x418/0x780 > [25338.590654] register_virtio_device+0x9e/0xe0 > [25338.595011] virtio_pci_probe+0xb3/0x140 > [25338.598941] local_pci_probe+0x41/0x90 > [25338.602689] work_for_cpu_fn+0x16/0x20 > [25338.606443] process_one_work+0x1a7/0x360 > [25338.610456] ? create_worker+0x1a0/0x1a0 > [25338.614381] worker_thread+0x1cf/0x390 > [25338.618132] ? create_worker+0x1a0/0x1a0 > [25338.622051] kthread+0x116/0x130 > [25338.625283] ? kthread_flush_work_fn+0x10/0x10 > [25338.629731] ret_from_fork+0x1f/0x40 > [25338.633395] virtio_blk: probe of virtio418 failed with error -16 > > The log : > "genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)" > was print because of the irq 0 is used by timer exclusive,and when > vp_find_vqs call vp_find_vqs_msix and return false twice for > whatever reason,then it will call vp_find_vqs_intx for the last try. > Because vp_dev->pci_dev->irq is zero,so it will be request irq 0 with > flag IRQF_SHARED,we will get a backtrace like above. > > When the pci device is vf,the intx > is not allowed and it will be 0.Even if the pci device is a pf, > we should remind that > irq 0 is almost be reserved or used for some device fixed Where does it say irq 0 is reserved on all platforms? I am not sure this is right. > like timer in x86 without IRQF_SHARED,so we can avoid call it. > > Signed-off-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx> > Suggested-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > --- > drivers/virtio/virtio_pci_common.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index ad258a9d3b9f..3208a2b149b9 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -362,6 +362,9 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > int i, err, queue_idx = 0; > > + if (vp_dev->pci_dev->irq == 0) > + return -EINVAL; > + Pls read the PCI spec: Interrupt Pin The Interrupt Pin register tells which interrupt pin the device (or device function) uses. A value of 1 corresponds to INTA#. A value of 2 corresponds to INTB#. A value of 3 corresponds to INTC#. A value of 4 corresponds to INTD#. Devices (or device functions) that do not use an interrupt pin must put a 0 in this register. Please check vp_dev->pci_dev->pin accordingly. > vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL); > if (!vp_dev->vqs) > return -ENOMEM; > -- > 2.17.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
