On Tue, Jul 15, 2025 at 9:35 AM Cindy Lu <l...@redhat.com> wrote:
>
> Hi Wenli,
>
> Could you please provide more details regarding the following:
>
> > \[ 84.703574\] vp-vdpa 0000:01:00.0: Failed to register to vdpa bus
> >
> > kernel answers: File exists
> >
> > # vdpa dev del vdpa0
>
> I suspect the device wasn't created successfully. Could it be that a
> vdpa0 already existed before you tried to create one?
It existed vdpa0 before being removed. btw, to reproduce it, it's
needed to operate twice for creating the vdpa0 device, then to remove
it.
# vdpa -jp dev config show vdpa0
{
Error: vdpa: device not found.
kernel answers: No such device
"config": {}
}
After first creating the vdpa0.
# vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.0 device_features
0x1
# vdpa -jp dev config show vdpa0
{
"config": {
"vdpa0": {}
}
}
# vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.0 device_features 0x1
[ 188.690040] vp-vdpa 0000:01:00.0: Failed to register to vdpa bus
kernel answers: File exists
# vdpa dev del vdpa0
Then Call Trace happened.
Best Regards, wenli
> Thanks,
> Cindy
>
> On Tue, Jul 15, 2025 at 9:19 AM Jason Wang <jasow...@redhat.com> wrote:
> >
> > Adding Cindy for help here.
> >
> > On Mon, Jul 14, 2025 at 9:18 PM Wenli Quan <wq...@redhat.com> wrote:
> > >
> > > Hello all:
> > >
> > > I am encountering an issue when creating a vp_vdpa device with feature
> > > provisioning enabled.
> > >
> > > In the vm:
> > >
> > > # uname -r
> > > 6.16.0-rc2+
> > >
> > > # cd /sys/bus/pci/drivers/virtio-pci/
> > >
> > > # echo 0000:01:00.0 > unbind
> > >
> > > # modprobe vp_vdpa
> > >
> > > # cd ../vp-vdpa/
> > >
> > > # echo "1af4 1041" > new_id
> > >
> > > # vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.0 device_features 0x1
> > >
> > > # vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.0 device_features 0x1
> > >
> > > [ 84.703574] vp-vdpa 0000:01:00.0: Failed to register to vdpa bus
> > >
> > > kernel answers: File exists
> > >
> > > # vdpa dev del vdpa0
> > >
> > >
> > > [ 194.055148] BUG: kernel NULL pointer dereference, address:
> > > 00000000000000d0
> > >
> > > [ 194.055698] #PF: supervisor read access in kernel mode
> > >
> > > [ 194.056100] #PF: error_code(0x0000) - not-present page
> > >
> > > [ 194.056497] PGD 7c7e067 P4D 0
> > >
> > > [ 194.056739] Oops: Oops: 0000 [#1] SMP
> > >
> > > [ 194.057040] CPU: 0 UID: 0 PID: 13582 Comm: vdpa Not tainted
> > > 6.16.0-rc2+ #6 PREEMPT(voluntary)
> > >
> > > [ 194.057697] Hardware name: Red Hat KVM/RHEL, BIOS
> > > edk2-20241117-2.el9_6.1 11/17/2024
> > >
> > > [ 194.058299] RIP: 0010:device_del+0x40/0x480
> > >
> > > [ 194.058623] Code: 00 00 55 48 89 fd 53 48 83 ec 20 4c 8b 7f 40 4c 89
> > > e7 65 48 8b 05 10 bf 73 01 48 89 44 24 18 31 c0 e8 b4 2f 63 00 48 8b 55
> > > 48 <0f> b6 82 d0 00 00 00 a8 01 75 09 83 c8 01 88 82 d0 00 00 00 4c 89
> > >
> > > [ 194.060031] RSP: 0018:ffa00000004dba90 EFLAGS: 00010246
> > >
> > > [ 194.060436] RAX: 0000000000000000 RBX: ff110000089f1720 RCX:
> > > ffffffffa05f2200
> > >
> > > [ 194.060976] RDX: 0000000000000000 RSI: ff11000018296800 RDI:
> > > ff11000018297080
> > >
> > > [ 194.061510] RBP: ff11000018297000 R08: ff1100000a3ea048 R09:
> > > ffa00000004dbc50
> > >
> > > [ 194.062051] R10: ff11000006abae00 R11: 0000000000000026 R12:
> > > ff11000018297080
> > >
> > > [ 194.062586] R13: ff1100000571c300 R14: ffa00000004dbc50 R15:
> > > 0000000000000000
> > >
> > > [ 194.063132] FS: 00007f03a6a95740(0000) GS:ff110000d8597000(0000)
> > > knlGS:0000000000000000
> > >
> > > [ 194.063748] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >
> > > [ 194.064189] CR2: 00000000000000d0 CR3: 0000000007830004 CR4:
> > > 0000000000773ef0
> > >
> > > [ 194.064722] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> > > 0000000000000000
> > >
> > > [ 194.065258] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7:
> > > 0000000000000400
> > >
> > > [ 194.065813] PKRU: 55555554
> > >
> > > [ 194.066022] Call Trace:
> > >
> > > [ 194.066240] <TASK>
> > >
> > > [ 194.066418] device_unregister+0x12/0x30
> > >
> > > [ 194.066724] vp_vdpa_dev_del+0x16/0x20 [vp_vdpa]
> > >
> > > [ 194.067078] vdpa_nl_cmd_dev_del_set_doit+0x67/0xe0 [vdpa]
> > >
> > > [ 194.067497] genl_family_rcv_msg_doit+0xd2/0x120
> > >
> > > [ 194.067863] genl_rcv_msg+0x182/0x2b0
> > >
> > > [ 194.068160] ? vdpa_nl_cmd_dev_get_dumpit+0xa0/0xa0 [vdpa]
> > >
> > > [ 194.068594] ? genl_family_rcv_msg_dumpit+0xf0/0xf0
> > >
> > > [ 194.068971] netlink_rcv_skb+0x57/0x100
> > >
> > > [ 194.069270] genl_rcv+0x28/0x40
> > >
> > > [ 194.069515] netlink_unicast+0x278/0x3a0
> > >
> > > [ 194.069828] netlink_sendmsg+0x1e7/0x420
> > >
> > > [ 194.070134] __sock_sendmsg+0x38/0x60
> > >
> > > [ 194.070414] ? move_addr_to_kernel.part.0+0x1b/0x60
> > >
> > > [ 194.070794] __sys_sendto+0x115/0x170
> > >
> > > [ 194.071086] ? __sys_recvmsg+0x6a/0xc0
> > >
> > > [ 194.071378] __x64_sys_sendto+0x24/0x30
> > >
> > > [ 194.071674] do_syscall_64+0x59/0x1f0
> > >
> > > [ 194.071963] entry_SYSCALL_64_after_hwframe+0x4b/0x53
> > >
> > > [ 194.072347] RIP: 0033:0x7f03a6ba7dea
> > >
> > > [ 194.072625] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3
> > > 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f
> > > 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
> > >
> > > [ 194.074021] RSP: 002b:00007ffceb0ebeb8 EFLAGS: 00000246 ORIG_RAX:
> > > 000000000000002c
> > >
> > > [ 194.074610] RAX: ffffffffffffffda RBX: 00005646e0680350 RCX:
> > > 00007f03a6ba7dea
> > >
> > > [ 194.075154] RDX: 0000000000000020 RSI: 00005646e0680350 RDI:
> > > 0000000000000003
> > >
> > > [ 194.075699] RBP: 00005646e06802a0 R08: 00007f03a6cae200 R09:
> > > 000000000000000c
> > >
> > > [ 194.076455] R10: 0000000000000000 R11: 0000000000000246 R12:
> > > 0000000000000000
> > >
> > > [ 194.077197] R13: 0000000000000000 R14: 00007ffceb0ec75d R15:
> > > 0000000000000064
> > >
> > > [ 194.077944] </TASK>
> > >
> > > [ 194.078321] Modules linked in: vp_vdpa vdpa kvm_intel kvm irqbypass
> > > fuse configfs xfs virtio_net net_failover failover virtio_pci
> > > virtio_pci_legacy_dev virtio_pci_modern_dev be2iscsi cxgb3i cxgb3 mdio
> > > libcxgbi libcxgb iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi
> > > autofs4
> > >
> > > [ 194.080556] CR2: 00000000000000d0
> > >
> > > [ 194.081040] ---[ end trace 0000000000000000 ]---
> > >
> > > [ 194.660537] RIP: 0010:device_del+0x40/0x480
> > >
> > > [ 194.662514] Code: 00 00 55 48 89 fd 53 48 83 ec 20 4c 8b 7f 40 4c 89
> > > e7 65 48 8b 05 10 bf 73 01 48 89 44 24 18 31 c0 e8 b4 2f 63 00 48 8b 55
> > > 48 <0f> b6 82 d0 00 00 00 a8 01 75 09 83 c8 01 88 82 d0 00 00 00 4c 89
> > >
> > > [ 194.664367] RSP: 0018:ffa00000004dba90 EFLAGS: 00010246
> > >
> > > [ 194.664996] RAX: 0000000000000000 RBX: ff110000089f1720 RCX:
> > > ffffffffa05f2200
> > >
> > > [ 194.665760] RDX: 0000000000000000 RSI: ff11000018296800 RDI:
> > > ff11000018297080
> > >
> > > [ 194.666527] RBP: ff11000018297000 R08: ff1100000a3ea048 R09:
> > > ffa00000004dbc50
> > >
> > > [ 194.667300] R10: ff11000006abae00 R11: 0000000000000026 R12:
> > > ff11000018297080
> > >
> > > [ 194.668066] R13: ff1100000571c300 R14: ffa00000004dbc50 R15:
> > > 0000000000000000
> > >
> > > [ 194.668823] FS: 00007f03a6a95740(0000) GS:ff110000d8597000(0000)
> > > knlGS:0000000000000000
> > >
> > > [ 194.669653] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >
> > > [ 194.670322] CR2: 00000000000000d0 CR3: 0000000007830004 CR4:
> > > 0000000000773ef0
> > >
> > > [ 194.671083] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> > > 0000000000000000
> > >
> > > [ 194.671845] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7:
> > > 0000000000000400
> > >
> > > [ 194.672607] PKRU: 55555554
> > >
> > > [ 194.673042] note: vdpa[13582] exited with irqs disabled
> > >
> > > Killed
> > >
> > >
> > > Best Regards,
> > >
> > >
> > > wenli
> >
> > Thanks
> >
>
