From e0f880b22b0d6dcf572cf745d91b1d976421b986 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 22 Oct 2009 15:06:06 +0200 Subject: [PATCH] virtio-pci: fix per-vq MSI-X request logic Commit 09026249739466036a0e3b5ab0e1816bd1c296c6 in 2.6.32-rc1 broke requesting IRQs for per-VQ MSI-X vectors: - vector number was used instead of the vector itself - we try to request an IRQ for VQ which does not have a callback handler This is a regression that causes warnings in kernel log, potentially lower performance as we need to scan vq list, and might cause system failure if the interrupt requested is in fact needed by another system. This was not noticed earlier because in most cases we were falling back on shared interrupt for all vqs. The warnings often look like this: virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 28 for MSI/MSI-X IRQ handler type mismatch for IRQ 1 current handler: i8042 Pid: 2400, comm: modprobe Tainted: G W 2.6.32-rc3-11952-gf3ed8d8-dirty #1 Call Trace: [] ? __setup_irq+0x299/0x304 [] ? request_threaded_irq+0x144/0x1c1 [] ? vring_interrupt+0x0/0x30 [] ? vp_try_to_find_vqs+0x583/0x5c7 [] ? skb_recv_done+0x0/0x34 [virtio_net] [] ? vp_find_vqs+0x2d/0x83 [] ? vp_get+0x3c/0x4e [] ? virtnet_probe+0x2f1/0x428 [virtio_net] [] ? skb_recv_done+0x0/0x34 [virtio_net] [] ? skb_xmit_done+0x0/0x39 [virtio_net] [] ? sysfs_do_create_link+0xcb/0x116 [] ? vp_get_status+0x14/0x16 [] ? virtio_dev_probe+0xa9/0xc8 [] ? driver_probe_device+0x8d/0x128 [] ? __driver_attach+0x4f/0x6f [] ? __driver_attach+0x0/0x6f [] ? bus_for_each_dev+0x43/0x74 [] ? bus_add_driver+0xea/0x22d [] ? driver_register+0xa7/0x111 [] ? init+0x0/0xc [virtio_net] [] ? do_one_initcall+0x50/0x148 [] ? sys_init_module+0xc5/0x21a [] ? system_call_fastpath+0x16/0x1b virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X Reported-by: Marcelo Tosatti Reported-by: Shirley Ma Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 4a1f1ebff7bf2..28d9cf7cf72f9 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -530,19 +530,22 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs, err = PTR_ERR(vqs[i]); goto error_find; } + + if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR) + continue; + /* allocate per-vq irq if available and necessary */ - if (vp_dev->per_vq_vectors) { - snprintf(vp_dev->msix_names[msix_vec], - sizeof *vp_dev->msix_names, - "%s-%s", - dev_name(&vp_dev->vdev.dev), names[i]); - err = request_irq(msix_vec, vring_interrupt, 0, - vp_dev->msix_names[msix_vec], - vqs[i]); - if (err) { - vp_del_vq(vqs[i]); - goto error_find; - } + snprintf(vp_dev->msix_names[msix_vec], + sizeof *vp_dev->msix_names, + "%s-%s", + dev_name(&vp_dev->vdev.dev), names[i]); + err = request_irq(vp_dev->msix_entries[msix_vec].vector, + vring_interrupt, 0, + vp_dev->msix_names[msix_vec], + vqs[i]); + if (err) { + vp_del_vq(vqs[i]); + goto error_find; } } return 0; -- 2.39.5