Michael S. Tsirkin
2009-Oct-22 13:06 UTC
[PATCH] virtio-pci: fix per-vq MSI-X request logic
Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1
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:
[<ffffffff81072aed>] ? __setup_irq+0x299/0x304
[<ffffffff81072ff3>] ? request_threaded_irq+0x144/0x1c1
[<ffffffff813455af>] ? vring_interrupt+0x0/0x30
[<ffffffff81346598>] ? vp_try_to_find_vqs+0x583/0x5c7
[<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net]
[<ffffffff81346609>] ? vp_find_vqs+0x2d/0x83
[<ffffffff81345d00>] ? vp_get+0x3c/0x4e
[<ffffffffa0016373>] ? virtnet_probe+0x2f1/0x428 [virtio_net]
[<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net]
[<ffffffffa00150d8>] ? skb_xmit_done+0x0/0x39 [virtio_net]
[<ffffffff8110ab92>] ? sysfs_do_create_link+0xcb/0x116
[<ffffffff81345cc2>] ? vp_get_status+0x14/0x16
[<ffffffff81345464>] ? virtio_dev_probe+0xa9/0xc8
[<ffffffff8122b11c>] ? driver_probe_device+0x8d/0x128
[<ffffffff8122b206>] ? __driver_attach+0x4f/0x6f
[<ffffffff8122b1b7>] ? __driver_attach+0x0/0x6f
[<ffffffff8122a9f9>] ? bus_for_each_dev+0x43/0x74
[<ffffffff8122a374>] ? bus_add_driver+0xea/0x22d
[<ffffffff8122b4a3>] ? driver_register+0xa7/0x111
[<ffffffffa001a000>] ? init+0x0/0xc [virtio_net]
[<ffffffff81009051>] ? do_one_initcall+0x50/0x148
[<ffffffff8106e117>] ? sys_init_module+0xc5/0x21a
[<ffffffff8100af02>] ? 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 <mtosatti at redhat.com>
Reported-by: Shirley Ma <xma at us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
Rusty, since this is a regression from 2.6.31,
I think we want to push this for 2.6.32.
Thanks!
drivers/virtio/virtio_pci.c | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 4a1f1eb..28d9cf7 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;
--
1.6.5.rc2
On Thu, Oct 22, 2009 at 03:06:06PM +0200, Michael S. Tsirkin wrote:> Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1 > 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.Works for me. Thanks Michael. Tested-by: Marcelo Tosatti <mtosatti at redhat.com>
Michael S. Tsirkin
2009-Oct-23 11:08 UTC
[PATCH] virtio-pci: fix per-vq MSI-X request logic
On Thu, Oct 22, 2009 at 03:06:06PM +0200, Michael S. Tsirkin wrote:> Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1 > 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: > [<ffffffff81072aed>] ? __setup_irq+0x299/0x304 > [<ffffffff81072ff3>] ? request_threaded_irq+0x144/0x1c1 > [<ffffffff813455af>] ? vring_interrupt+0x0/0x30 > [<ffffffff81346598>] ? vp_try_to_find_vqs+0x583/0x5c7 > [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] > [<ffffffff81346609>] ? vp_find_vqs+0x2d/0x83 > [<ffffffff81345d00>] ? vp_get+0x3c/0x4e > [<ffffffffa0016373>] ? virtnet_probe+0x2f1/0x428 [virtio_net] > [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] > [<ffffffffa00150d8>] ? skb_xmit_done+0x0/0x39 [virtio_net] > [<ffffffff8110ab92>] ? sysfs_do_create_link+0xcb/0x116 > [<ffffffff81345cc2>] ? vp_get_status+0x14/0x16 > [<ffffffff81345464>] ? virtio_dev_probe+0xa9/0xc8 > [<ffffffff8122b11c>] ? driver_probe_device+0x8d/0x128 > [<ffffffff8122b206>] ? __driver_attach+0x4f/0x6f > [<ffffffff8122b1b7>] ? __driver_attach+0x0/0x6f > [<ffffffff8122a9f9>] ? bus_for_each_dev+0x43/0x74 > [<ffffffff8122a374>] ? bus_add_driver+0xea/0x22d > [<ffffffff8122b4a3>] ? driver_register+0xa7/0x111 > [<ffffffffa001a000>] ? init+0x0/0xc [virtio_net] > [<ffffffff81009051>] ? do_one_initcall+0x50/0x148 > [<ffffffff8106e117>] ? sys_init_module+0xc5/0x21a > [<ffffffff8100af02>] ? 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 <mtosatti at redhat.com> > Reported-by: Shirley Ma <xma at us.ibm.com> > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>You can now add Tested-by: Shirley Ma <mashirle at us.ibm.com> Tested-by: Marcelo Tosatti <mtosatti at redhat.com>