| Message ID | 8d6b1fc3b5d3b6f5e8b212ef690691a52fbefaff.1446162273.git.luto@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 30.10.2015 um 02:09 schrieb Andy Lutomirski: > From: "Michael S. Tsirkin" <mst@redhat.com> > > Once virtio starts using the DMA API, we won't be able to safely DMA > from the stack. virtio-net does a couple of config DMA requests > from small stack buffers -- switch to using dynamically-allocated > memory. > > This should have no effect on any performance-critical code paths. > > [I wrote the subject and commit message. mst wrote the code. --luto] > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > signed-off-by: Michael S. Tsirkin <mst@redhat.com> I still get an error when using multiqueue: # ethtool -L eth0 combined 4 [ 33.534686] virtio_ccw 0.0.000d: DMA-API: device driver maps memory from stack [addr=00000000629e7c06] [ 33.534704] ------------[ cut here ]------------ [ 33.534705] WARNING: at lib/dma-debug.c:1169 [ 33.534706] Modules linked in: dm_multipath [ 33.534709] CPU: 1 PID: 1087 Comm: ethtool Not tainted 4.3.0-rc3+ #269 [ 33.534710] task: 00000000616f9978 ti: 00000000629e4000 task.ti: 00000000629e4000 [ 33.534712] Krnl PSW : 0704d00180000000 00000000005869d2 (check_for_stack+0xb2/0x118) [ 33.534716] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3 Krnl GPRS: 000000000000006a 0000000000d60f44 000000000000005a 0000000064ee0870 [ 33.534718] 00000000005869ce 0000000000000000 0000000000000001 00000000629e7c06 [ 33.534719] 0000000000000000 0000000000000c06 0000000000000002 000000006467f800 [ 33.534720] 0000000064673428 00000000629e7c06 00000000005869ce 00000000629e7928 [ 33.534726] Krnl Code: 00000000005869c2: c0200024ad4e larl %r2,a1c45e 00000000005869c8: c0e5ffe6d6fc brasl %r14,2617c0 #00000000005869ce: a7f40001 brc 15,5869d0 >00000000005869d2: c010003465eb larl %r1,c135a8 00000000005869d8: e31010000012 lt %r1,0(%r1) 00000000005869de: a784000a brc 8,5869f2 00000000005869e2: e340f0b00004 lg %r4,176(%r15) 00000000005869e8: ebcff0a00004 lmg %r12,%r15,160(%r15) [ 33.534736] Call Trace: [ 33.534737] ([<00000000005869ce>] check_for_stack+0xae/0x118) [ 33.534738] [<0000000000586e3c>] debug_dma_map_page+0x114/0x160 [ 33.534740] [<00000000005a31f8>] vring_map_one_sg.isra.7+0x98/0xc0 [ 33.534742] [<00000000005a3b72>] virtqueue_add_sgs+0x1e2/0x788 [ 33.534744] [<0000000000618afc>] virtnet_send_command+0xcc/0x140 [ 33.534745] [<0000000000618c0c>] virtnet_set_queues+0x9c/0x110 [ 33.534747] [<0000000000619928>] virtnet_set_channels+0x78/0xe0 [ 33.534748] [<00000000006f63ea>] ethtool_set_channels+0x62/0x88 [ 33.534750] [<00000000006f8900>] dev_ethtool+0x10d8/0x1a48 [ 33.534752] [<000000000070c540>] dev_ioctl+0x190/0x510 [ 33.534754] [<00000000006cf2da>] sock_do_ioctl+0x7a/0x90 [ 33.534755] [<00000000006cf840>] sock_ioctl+0x1e8/0x2d0 [ 33.534758] [<00000000002e6c78>] do_vfs_ioctl+0x3a8/0x508 [ 33.534759] [<00000000002e6e7c>] SyS_ioctl+0xa4/0xb8 [ 33.534762] [<00000000008231ec>] system_call+0x244/0x264 [ 33.534763] [<000003ff922026d2>] 0x3ff922026d2 [ 33.534764] Last Breaking-Event-Address: [ 33.534765] [<00000000005869ce>] check_for_stack+0xae/0x118 [ 33.534766] ---[ end trace 2379df65f4decfc4 ]--- > --- > drivers/net/virtio_net.c | 34 +++++++++++++++++++--------------- > 1 file changed, 19 insertions(+), 15 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index d8838dedb7a4..f94ab786088f 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -140,6 +140,12 @@ struct virtnet_info { > > /* CPU hot plug notifier */ > struct notifier_block nb; > + > + /* Control VQ buffers: protected by the rtnl lock */ > + struct virtio_net_ctrl_hdr ctrl_hdr; > + virtio_net_ctrl_ack ctrl_status; > + u8 ctrl_promisc; > + u8 ctrl_allmulti; > }; > > struct padded_vnet_hdr { > @@ -976,31 +982,30 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > struct scatterlist *out) > { > struct scatterlist *sgs[4], hdr, stat; > - struct virtio_net_ctrl_hdr ctrl; > - virtio_net_ctrl_ack status = ~0; > unsigned out_num = 0, tmp; > > /* Caller should know better */ > BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); > > - ctrl.class = class; > - ctrl.cmd = cmd; > + vi->ctrl_status = ~0; > + vi->ctrl_hdr.class = class; > + vi->ctrl_hdr.cmd = cmd; > /* Add header */ > - sg_init_one(&hdr, &ctrl, sizeof(ctrl)); > + sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr)); > sgs[out_num++] = &hdr; > > if (out) > sgs[out_num++] = out; > > /* Add return status. */ > - sg_init_one(&stat, &status, sizeof(status)); > + sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status)); > sgs[out_num] = &stat; > > BUG_ON(out_num + 1 > ARRAY_SIZE(sgs)); > virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC); > > if (unlikely(!virtqueue_kick(vi->cvq))) > - return status == VIRTIO_NET_OK; > + return vi->ctrl_status == VIRTIO_NET_OK; > > /* Spin for a response, the kick causes an ioport write, trapping > * into the hypervisor, so the request should be handled immediately. > @@ -1009,7 +1014,7 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > !virtqueue_is_broken(vi->cvq)) > cpu_relax(); > > - return status == VIRTIO_NET_OK; > + return vi->ctrl_status == VIRTIO_NET_OK; > } > > static int virtnet_set_mac_address(struct net_device *dev, void *p) > @@ -1151,7 +1156,6 @@ static void virtnet_set_rx_mode(struct net_device *dev) > { > struct virtnet_info *vi = netdev_priv(dev); > struct scatterlist sg[2]; > - u8 promisc, allmulti; > struct virtio_net_ctrl_mac *mac_data; > struct netdev_hw_addr *ha; > int uc_count; > @@ -1163,22 +1167,22 @@ static void virtnet_set_rx_mode(struct net_device *dev) > if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) > return; > > - promisc = ((dev->flags & IFF_PROMISC) != 0); > - allmulti = ((dev->flags & IFF_ALLMULTI) != 0); > + vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0); > + vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0); > > - sg_init_one(sg, &promisc, sizeof(promisc)); > + sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc)); > > if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, > VIRTIO_NET_CTRL_RX_PROMISC, sg)) > dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", > - promisc ? "en" : "dis"); > + vi->ctrl_promisc ? "en" : "dis"); > > - sg_init_one(sg, &allmulti, sizeof(allmulti)); > + sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti)); > > if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, > VIRTIO_NET_CTRL_RX_ALLMULTI, sg)) > dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", > - allmulti ? "en" : "dis"); > + vi->ctrl_allmulti ? "en" : "dis"); > > uc_count = netdev_uc_count(dev); > mc_count = netdev_mc_count(dev); > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Oct 30, 2015 at 6:55 AM, Christian Borntraeger <borntraeger@de.ibm.com> wrote: > Am 30.10.2015 um 02:09 schrieb Andy Lutomirski: >> From: "Michael S. Tsirkin" <mst@redhat.com> >> >> Once virtio starts using the DMA API, we won't be able to safely DMA >> from the stack. virtio-net does a couple of config DMA requests >> from small stack buffers -- switch to using dynamically-allocated >> memory. >> >> This should have no effect on any performance-critical code paths. >> >> [I wrote the subject and commit message. mst wrote the code. --luto] >> >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > I still get an error when using multiqueue: > > # ethtool -L eth0 combined 4 > [ 33.534686] virtio_ccw 0.0.000d: DMA-API: device driver maps memory from stack [addr=00000000629e7c06] Fixed in my branch, I think. --Andy -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d8838dedb7a4..f94ab786088f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -140,6 +140,12 @@ struct virtnet_info { /* CPU hot plug notifier */ struct notifier_block nb; + + /* Control VQ buffers: protected by the rtnl lock */ + struct virtio_net_ctrl_hdr ctrl_hdr; + virtio_net_ctrl_ack ctrl_status; + u8 ctrl_promisc; + u8 ctrl_allmulti; }; struct padded_vnet_hdr { @@ -976,31 +982,30 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, struct scatterlist *out) { struct scatterlist *sgs[4], hdr, stat; - struct virtio_net_ctrl_hdr ctrl; - virtio_net_ctrl_ack status = ~0; unsigned out_num = 0, tmp; /* Caller should know better */ BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); - ctrl.class = class; - ctrl.cmd = cmd; + vi->ctrl_status = ~0; + vi->ctrl_hdr.class = class; + vi->ctrl_hdr.cmd = cmd; /* Add header */ - sg_init_one(&hdr, &ctrl, sizeof(ctrl)); + sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr)); sgs[out_num++] = &hdr; if (out) sgs[out_num++] = out; /* Add return status. */ - sg_init_one(&stat, &status, sizeof(status)); + sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status)); sgs[out_num] = &stat; BUG_ON(out_num + 1 > ARRAY_SIZE(sgs)); virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC); if (unlikely(!virtqueue_kick(vi->cvq))) - return status == VIRTIO_NET_OK; + return vi->ctrl_status == VIRTIO_NET_OK; /* Spin for a response, the kick causes an ioport write, trapping * into the hypervisor, so the request should be handled immediately. @@ -1009,7 +1014,7 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, !virtqueue_is_broken(vi->cvq)) cpu_relax(); - return status == VIRTIO_NET_OK; + return vi->ctrl_status == VIRTIO_NET_OK; } static int virtnet_set_mac_address(struct net_device *dev, void *p) @@ -1151,7 +1156,6 @@ static void virtnet_set_rx_mode(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); struct scatterlist sg[2]; - u8 promisc, allmulti; struct virtio_net_ctrl_mac *mac_data; struct netdev_hw_addr *ha; int uc_count; @@ -1163,22 +1167,22 @@ static void virtnet_set_rx_mode(struct net_device *dev) if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) return; - promisc = ((dev->flags & IFF_PROMISC) != 0); - allmulti = ((dev->flags & IFF_ALLMULTI) != 0); + vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0); + vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0); - sg_init_one(sg, &promisc, sizeof(promisc)); + sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, VIRTIO_NET_CTRL_RX_PROMISC, sg)) dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", - promisc ? "en" : "dis"); + vi->ctrl_promisc ? "en" : "dis"); - sg_init_one(sg, &allmulti, sizeof(allmulti)); + sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, VIRTIO_NET_CTRL_RX_ALLMULTI, sg)) dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", - allmulti ? "en" : "dis"); + vi->ctrl_allmulti ? "en" : "dis"); uc_count = netdev_uc_count(dev); mc_count = netdev_mc_count(dev);