2020-10-23 08:00:06

by Zenghui Yu

[permalink] [raw]
Subject: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

When unbinding the hns3 driver with the HNS3 VF, I got the following
kernel panic:

[ 265.709989] Unable to handle kernel paging request at virtual address ffff800054627000
[ 265.717928] Mem abort info:
[ 265.720740] ESR = 0x96000047
[ 265.723810] EC = 0x25: DABT (current EL), IL = 32 bits
[ 265.729126] SET = 0, FnV = 0
[ 265.732195] EA = 0, S1PTW = 0
[ 265.735351] Data abort info:
[ 265.738227] ISV = 0, ISS = 0x00000047
[ 265.742071] CM = 0, WnR = 1
[ 265.745055] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000009b54000
[ 265.751753] [ffff800054627000] pgd=0000202ffffff003, p4d=0000202ffffff003, pud=00002020020eb003, pmd=00000020a0dfc003, pte=0000000000000000
[ 265.764314] Internal error: Oops: 96000047 [#1] SMP
[ 265.830357] CPU: 61 PID: 20319 Comm: bash Not tainted 5.9.0+ #206
[ 265.836423] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 1.05 09/18/2019
[ 265.843873] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
[ 265.843890] pc : hclgevf_cmd_uninit+0xbc/0x300
[ 265.861988] lr : hclgevf_cmd_uninit+0xb0/0x300
[ 265.861992] sp : ffff80004c983b50
[ 265.881411] pmr_save: 000000e0
[ 265.884453] x29: ffff80004c983b50 x28: ffff20280bbce500
[ 265.889744] x27: 0000000000000000 x26: 0000000000000000
[ 265.895034] x25: ffff800011a1f000 x24: ffff800011a1fe90
[ 265.900325] x23: ffff0020ce9b00d8 x22: ffff0020ce9b0150
[ 265.905616] x21: ffff800010d70e90 x20: ffff800010d70e90
[ 265.910906] x19: ffff0020ce9b0080 x18: 0000000000000004
[ 265.916198] x17: 0000000000000000 x16: ffff800011ae32e8
[ 265.916201] x15: 0000000000000028 x14: 0000000000000002
[ 265.916204] x13: ffff800011ae32e8 x12: 0000000000012ad8
[ 265.946619] x11: ffff80004c983b50 x10: 0000000000000000
[ 265.951911] x9 : ffff8000115d0888 x8 : 0000000000000000
[ 265.951914] x7 : ffff800011890b20 x6 : c0000000ffff7fff
[ 265.951917] x5 : ffff80004c983930 x4 : 0000000000000001
[ 265.951919] x3 : ffffa027eec1b000 x2 : 2b78ccbbff369100
[ 265.964487] x1 : 0000000000000000 x0 : ffff800054627000
[ 265.964491] Call trace:
[ 265.964494] hclgevf_cmd_uninit+0xbc/0x300
[ 265.964496] hclgevf_uninit_ae_dev+0x9c/0xe8
[ 265.964501] hnae3_unregister_ae_dev+0xb0/0x130
[ 265.964516] hns3_remove+0x34/0x88 [hns3]
[ 266.009683] pci_device_remove+0x48/0xf0
[ 266.009692] device_release_driver_internal+0x114/0x1e8
[ 266.030058] device_driver_detach+0x28/0x38
[ 266.034224] unbind_store+0xd4/0x108
[ 266.037784] drv_attr_store+0x40/0x58
[ 266.041435] sysfs_kf_write+0x54/0x80
[ 266.045081] kernfs_fop_write+0x12c/0x250
[ 266.049076] vfs_write+0xc4/0x248
[ 266.052378] ksys_write+0x74/0xf8
[ 266.055677] __arm64_sys_write+0x24/0x30
[ 266.059584] el0_svc_common.constprop.3+0x84/0x270
[ 266.064354] do_el0_svc+0x34/0xa0
[ 266.067658] el0_svc+0x38/0x40
[ 266.070700] el0_sync_handler+0x8c/0xb0
[ 266.074519] el0_sync+0x140/0x180

It looks like the BAR memory region had already been unmapped before we
start clearing CMDQ registers in it, which is pretty bad and the kernel
happily kills itself because of a Current EL Data Abort (on arm64).

Moving the CMDQ uninitialization a bit early fixes the issue for me.

Signed-off-by: Zenghui Yu <[email protected]>
---

I have almost zero knowledge about the hns3 driver. You can regard this
as a report and make a better fix if possible.

I can't even figure out that how can we live with this issue for a long
time... It should exists since commit 34f81f049e35 ("net: hns3: clear
command queue's registers when unloading VF driver"), where we start
writing something into the unmapped area.

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
index 50c84c5e65d2..c8e3fdd5999c 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
@@ -3262,8 +3262,8 @@ static void hclgevf_uninit_hdev(struct hclgevf_dev *hdev)
hclgevf_uninit_msi(hdev);
}

- hclgevf_pci_uninit(hdev);
hclgevf_cmd_uninit(hdev);
+ hclgevf_pci_uninit(hdev);
hclgevf_uninit_mac_list(hdev);
}

--
2.19.1


2020-10-23 08:01:52

by Yunsheng Lin

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On 2020/10/23 13:15, Zenghui Yu wrote:
> When unbinding the hns3 driver with the HNS3 VF, I got the following
> kernel panic:
>
> [ 265.709989] Unable to handle kernel paging request at virtual address ffff800054627000
> [ 265.717928] Mem abort info:
> [ 265.720740] ESR = 0x96000047
> [ 265.723810] EC = 0x25: DABT (current EL), IL = 32 bits
> [ 265.729126] SET = 0, FnV = 0
> [ 265.732195] EA = 0, S1PTW = 0
> [ 265.735351] Data abort info:
> [ 265.738227] ISV = 0, ISS = 0x00000047
> [ 265.742071] CM = 0, WnR = 1
> [ 265.745055] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000009b54000
> [ 265.751753] [ffff800054627000] pgd=0000202ffffff003, p4d=0000202ffffff003, pud=00002020020eb003, pmd=00000020a0dfc003, pte=0000000000000000
> [ 265.764314] Internal error: Oops: 96000047 [#1] SMP
> [ 265.830357] CPU: 61 PID: 20319 Comm: bash Not tainted 5.9.0+ #206
> [ 265.836423] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 1.05 09/18/2019
> [ 265.843873] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
> [ 265.843890] pc : hclgevf_cmd_uninit+0xbc/0x300
> [ 265.861988] lr : hclgevf_cmd_uninit+0xb0/0x300
> [ 265.861992] sp : ffff80004c983b50
> [ 265.881411] pmr_save: 000000e0
> [ 265.884453] x29: ffff80004c983b50 x28: ffff20280bbce500
> [ 265.889744] x27: 0000000000000000 x26: 0000000000000000
> [ 265.895034] x25: ffff800011a1f000 x24: ffff800011a1fe90
> [ 265.900325] x23: ffff0020ce9b00d8 x22: ffff0020ce9b0150
> [ 265.905616] x21: ffff800010d70e90 x20: ffff800010d70e90
> [ 265.910906] x19: ffff0020ce9b0080 x18: 0000000000000004
> [ 265.916198] x17: 0000000000000000 x16: ffff800011ae32e8
> [ 265.916201] x15: 0000000000000028 x14: 0000000000000002
> [ 265.916204] x13: ffff800011ae32e8 x12: 0000000000012ad8
> [ 265.946619] x11: ffff80004c983b50 x10: 0000000000000000
> [ 265.951911] x9 : ffff8000115d0888 x8 : 0000000000000000
> [ 265.951914] x7 : ffff800011890b20 x6 : c0000000ffff7fff
> [ 265.951917] x5 : ffff80004c983930 x4 : 0000000000000001
> [ 265.951919] x3 : ffffa027eec1b000 x2 : 2b78ccbbff369100
> [ 265.964487] x1 : 0000000000000000 x0 : ffff800054627000
> [ 265.964491] Call trace:
> [ 265.964494] hclgevf_cmd_uninit+0xbc/0x300
> [ 265.964496] hclgevf_uninit_ae_dev+0x9c/0xe8
> [ 265.964501] hnae3_unregister_ae_dev+0xb0/0x130
> [ 265.964516] hns3_remove+0x34/0x88 [hns3]
> [ 266.009683] pci_device_remove+0x48/0xf0
> [ 266.009692] device_release_driver_internal+0x114/0x1e8
> [ 266.030058] device_driver_detach+0x28/0x38
> [ 266.034224] unbind_store+0xd4/0x108
> [ 266.037784] drv_attr_store+0x40/0x58
> [ 266.041435] sysfs_kf_write+0x54/0x80
> [ 266.045081] kernfs_fop_write+0x12c/0x250
> [ 266.049076] vfs_write+0xc4/0x248
> [ 266.052378] ksys_write+0x74/0xf8
> [ 266.055677] __arm64_sys_write+0x24/0x30
> [ 266.059584] el0_svc_common.constprop.3+0x84/0x270
> [ 266.064354] do_el0_svc+0x34/0xa0
> [ 266.067658] el0_svc+0x38/0x40
> [ 266.070700] el0_sync_handler+0x8c/0xb0
> [ 266.074519] el0_sync+0x140/0x180
>
> It looks like the BAR memory region had already been unmapped before we
> start clearing CMDQ registers in it, which is pretty bad and the kernel
> happily kills itself because of a Current EL Data Abort (on arm64).
>
> Moving the CMDQ uninitialization a bit early fixes the issue for me.

Yes, this seems a obvious bug, and below patch seems the obvious fix too.

We has testcase to test the loading and unloading process, but does not
seem to catch this error, and testing it again using the latest internal
version seems ok too:

[root@localhost ~]# rmmod hclgevf
[ 8035.010715] hns3 0000:7d:01.0 eth8: net stop
[ 8035.079917] hns3 0000:7d:01.0 eth8: link down
[ 8036.402491] hns3 0000:7d:01.1 eth9: net stop
[ 8036.472946] hns3 0000:7d:01.1 eth9: link down
[root@localhost ~]# rmmod hns3
[ 8045.938705] hns3 0000:bd:00.3 eth7: net stop
[ 8046.354308] hns3 0000:bd:00.2 eth6: net stop
[ 8046.627653] hns3 0000:bd:00.1 eth5: net stop
[ 8046.632251] hns3 0000:bd:00.1 eth5: link down
[ 8047.050235] hns3 0000:bd:00.0 eth4: net stop
[ 8047.054837] hns3 0000:bd:00.0 eth4: link down
[ 8047.340528] hns3 0000:7d:00.3 eth3: net stop
[ 8047.347633] hns3 0000:7d:00.3 eth3: link down
[ 8048.879299] hns3 0000:7d:00.2 eth2: net stop
[ 8050.271999] hns3 0000:7d:00.1 eth1: net stop
[ 8050.278755] hns3 0000:7d:00.1 eth1: link down
[ 8051.650607] pci 0000:7d:01.0: Removing from iommu group 44
[ 8051.657909] pci 0000:7d:01.1: Removing from iommu group 45
[ 8052.794671] hns3 0000:7d:00.0 eth0: net stop
[ 8052.800385] hns3 0000:7d:00.0 eth0: link down
[root@localhost ~]#
[root@localhost ~]#


Do you care to provide the testcase for above calltrace?

>
> Signed-off-by: Zenghui Yu <[email protected]>
> ---
>
> I have almost zero knowledge about the hns3 driver. You can regard this
> as a report and make a better fix if possible.
>
> I can't even figure out that how can we live with this issue for a long
> time... It should exists since commit 34f81f049e35 ("net: hns3: clear
> command queue's registers when unloading VF driver"), where we start
> writing something into the unmapped area.
>
> drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
> index 50c84c5e65d2..c8e3fdd5999c 100644
> --- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
> @@ -3262,8 +3262,8 @@ static void hclgevf_uninit_hdev(struct hclgevf_dev *hdev)
> hclgevf_uninit_msi(hdev);
> }
>
> - hclgevf_pci_uninit(hdev);
> hclgevf_cmd_uninit(hdev);
> + hclgevf_pci_uninit(hdev);
> hclgevf_uninit_mac_list(hdev);
> }
>
>

2020-10-23 08:11:38

by Zenghui Yu

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On 2020/10/23 14:22, Yunsheng Lin wrote:
> On 2020/10/23 13:15, Zenghui Yu wrote:
>> When unbinding the hns3 driver with the HNS3 VF, I got the following
>> kernel panic:
>>
>> [ 265.709989] Unable to handle kernel paging request at virtual address ffff800054627000
>> [ 265.717928] Mem abort info:
>> [ 265.720740] ESR = 0x96000047
>> [ 265.723810] EC = 0x25: DABT (current EL), IL = 32 bits
>> [ 265.729126] SET = 0, FnV = 0
>> [ 265.732195] EA = 0, S1PTW = 0
>> [ 265.735351] Data abort info:
>> [ 265.738227] ISV = 0, ISS = 0x00000047
>> [ 265.742071] CM = 0, WnR = 1
>> [ 265.745055] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000009b54000
>> [ 265.751753] [ffff800054627000] pgd=0000202ffffff003, p4d=0000202ffffff003, pud=00002020020eb003, pmd=00000020a0dfc003, pte=0000000000000000
>> [ 265.764314] Internal error: Oops: 96000047 [#1] SMP
>> [ 265.830357] CPU: 61 PID: 20319 Comm: bash Not tainted 5.9.0+ #206
>> [ 265.836423] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 1.05 09/18/2019
>> [ 265.843873] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
>> [ 265.843890] pc : hclgevf_cmd_uninit+0xbc/0x300
>> [ 265.861988] lr : hclgevf_cmd_uninit+0xb0/0x300
>> [ 265.861992] sp : ffff80004c983b50
>> [ 265.881411] pmr_save: 000000e0
>> [ 265.884453] x29: ffff80004c983b50 x28: ffff20280bbce500
>> [ 265.889744] x27: 0000000000000000 x26: 0000000000000000
>> [ 265.895034] x25: ffff800011a1f000 x24: ffff800011a1fe90
>> [ 265.900325] x23: ffff0020ce9b00d8 x22: ffff0020ce9b0150
>> [ 265.905616] x21: ffff800010d70e90 x20: ffff800010d70e90
>> [ 265.910906] x19: ffff0020ce9b0080 x18: 0000000000000004
>> [ 265.916198] x17: 0000000000000000 x16: ffff800011ae32e8
>> [ 265.916201] x15: 0000000000000028 x14: 0000000000000002
>> [ 265.916204] x13: ffff800011ae32e8 x12: 0000000000012ad8
>> [ 265.946619] x11: ffff80004c983b50 x10: 0000000000000000
>> [ 265.951911] x9 : ffff8000115d0888 x8 : 0000000000000000
>> [ 265.951914] x7 : ffff800011890b20 x6 : c0000000ffff7fff
>> [ 265.951917] x5 : ffff80004c983930 x4 : 0000000000000001
>> [ 265.951919] x3 : ffffa027eec1b000 x2 : 2b78ccbbff369100
>> [ 265.964487] x1 : 0000000000000000 x0 : ffff800054627000
>> [ 265.964491] Call trace:
>> [ 265.964494] hclgevf_cmd_uninit+0xbc/0x300
>> [ 265.964496] hclgevf_uninit_ae_dev+0x9c/0xe8
>> [ 265.964501] hnae3_unregister_ae_dev+0xb0/0x130
>> [ 265.964516] hns3_remove+0x34/0x88 [hns3]
>> [ 266.009683] pci_device_remove+0x48/0xf0
>> [ 266.009692] device_release_driver_internal+0x114/0x1e8
>> [ 266.030058] device_driver_detach+0x28/0x38
>> [ 266.034224] unbind_store+0xd4/0x108
>> [ 266.037784] drv_attr_store+0x40/0x58
>> [ 266.041435] sysfs_kf_write+0x54/0x80
>> [ 266.045081] kernfs_fop_write+0x12c/0x250
>> [ 266.049076] vfs_write+0xc4/0x248
>> [ 266.052378] ksys_write+0x74/0xf8
>> [ 266.055677] __arm64_sys_write+0x24/0x30
>> [ 266.059584] el0_svc_common.constprop.3+0x84/0x270
>> [ 266.064354] do_el0_svc+0x34/0xa0
>> [ 266.067658] el0_svc+0x38/0x40
>> [ 266.070700] el0_sync_handler+0x8c/0xb0
>> [ 266.074519] el0_sync+0x140/0x180
>>
>> It looks like the BAR memory region had already been unmapped before we
>> start clearing CMDQ registers in it, which is pretty bad and the kernel
>> happily kills itself because of a Current EL Data Abort (on arm64).
>>
>> Moving the CMDQ uninitialization a bit early fixes the issue for me.
>
> Yes, this seems a obvious bug, and below patch seems the obvious fix too.
>
> We has testcase to test the loading and unloading process, but does not
> seem to catch this error, and testing it again using the latest internal
> version seems ok too:

I don't have access to the internal version ;-) I use mainline instead.

> [root@localhost ~]# rmmod hclgevf
> [ 8035.010715] hns3 0000:7d:01.0 eth8: net stop
> [ 8035.079917] hns3 0000:7d:01.0 eth8: link down
> [ 8036.402491] hns3 0000:7d:01.1 eth9: net stop
> [ 8036.472946] hns3 0000:7d:01.1 eth9: link down
> [root@localhost ~]# rmmod hns3
> [ 8045.938705] hns3 0000:bd:00.3 eth7: net stop
> [ 8046.354308] hns3 0000:bd:00.2 eth6: net stop
> [ 8046.627653] hns3 0000:bd:00.1 eth5: net stop
> [ 8046.632251] hns3 0000:bd:00.1 eth5: link down
> [ 8047.050235] hns3 0000:bd:00.0 eth4: net stop
> [ 8047.054837] hns3 0000:bd:00.0 eth4: link down
> [ 8047.340528] hns3 0000:7d:00.3 eth3: net stop
> [ 8047.347633] hns3 0000:7d:00.3 eth3: link down
> [ 8048.879299] hns3 0000:7d:00.2 eth2: net stop
> [ 8050.271999] hns3 0000:7d:00.1 eth1: net stop
> [ 8050.278755] hns3 0000:7d:00.1 eth1: link down
> [ 8051.650607] pci 0000:7d:01.0: Removing from iommu group 44
> [ 8051.657909] pci 0000:7d:01.1: Removing from iommu group 45
> [ 8052.794671] hns3 0000:7d:00.0 eth0: net stop
> [ 8052.800385] hns3 0000:7d:00.0 eth0: link down
> [root@localhost ~]#
> [root@localhost ~]#
>
>
> Do you care to provide the testcase for above calltrace?

I noticed it with VFIO, but it's easy to reproduce it manually. Here you
go:

# cat /sys/bus/pci/devices/0000\:7d\:00.2/sriov_totalvfs
3
# echo 3 > /sys/bus/pci/devices/0000\:7d\:00.2/sriov_numvfs
# lspci | grep "Virtual Function"
7d:01.6 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
Network Controller (Virtual Function) (rev 21)
7d:01.7 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
Network Controller (Virtual Function) (rev 21)
7d:02.0 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
Network Controller (Virtual Function) (rev 21)
# echo 0000:7d:01.6 > /sys/bus/pci/devices/0000:7d:01.6/driver/unbind


Thanks

>>
>> Signed-off-by: Zenghui Yu <[email protected]>
>> ---
>>
>> I have almost zero knowledge about the hns3 driver. You can regard this
>> as a report and make a better fix if possible.
>>
>> I can't even figure out that how can we live with this issue for a long
>> time... It should exists since commit 34f81f049e35 ("net: hns3: clear
>> command queue's registers when unloading VF driver"), where we start
>> writing something into the unmapped area.
>>
>> drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
>> index 50c84c5e65d2..c8e3fdd5999c 100644
>> --- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
>> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
>> @@ -3262,8 +3262,8 @@ static void hclgevf_uninit_hdev(struct hclgevf_dev *hdev)
>> hclgevf_uninit_msi(hdev);
>> }
>>
>> - hclgevf_pci_uninit(hdev);
>> hclgevf_cmd_uninit(hdev);
>> + hclgevf_pci_uninit(hdev);
>> hclgevf_uninit_mac_list(hdev);
>> }
>>
>>
> .
>

2020-10-27 00:09:28

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On Fri, 23 Oct 2020 15:01:14 +0800 Zenghui Yu wrote:
> On 2020/10/23 14:22, Yunsheng Lin wrote:
> > On 2020/10/23 13:15, Zenghui Yu wrote:
> >> When unbinding the hns3 driver with the HNS3 VF, I got the following
> >> kernel panic:
> >>
> >> [ 265.709989] Unable to handle kernel paging request at virtual address ffff800054627000
> >> [ 265.717928] Mem abort info:
> >> [ 265.720740] ESR = 0x96000047
> >> [ 265.723810] EC = 0x25: DABT (current EL), IL = 32 bits
> >> [ 265.729126] SET = 0, FnV = 0
> >> [ 265.732195] EA = 0, S1PTW = 0
> >> [ 265.735351] Data abort info:
> >> [ 265.738227] ISV = 0, ISS = 0x00000047
> >> [ 265.742071] CM = 0, WnR = 1
> >> [ 265.745055] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000009b54000
> >> [ 265.751753] [ffff800054627000] pgd=0000202ffffff003, p4d=0000202ffffff003, pud=00002020020eb003, pmd=00000020a0dfc003, pte=0000000000000000
> >> [ 265.764314] Internal error: Oops: 96000047 [#1] SMP
> >> [ 265.830357] CPU: 61 PID: 20319 Comm: bash Not tainted 5.9.0+ #206
> >> [ 265.836423] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 1.05 09/18/2019
> >
> > Do you care to provide the testcase for above calltrace?
>
> I noticed it with VFIO, but it's easy to reproduce it manually. Here you
> go:
>
> # cat /sys/bus/pci/devices/0000\:7d\:00.2/sriov_totalvfs
> 3
> # echo 3 > /sys/bus/pci/devices/0000\:7d\:00.2/sriov_numvfs
> # lspci | grep "Virtual Function"
> 7d:01.6 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
> Network Controller (Virtual Function) (rev 21)
> 7d:01.7 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
> Network Controller (Virtual Function) (rev 21)
> 7d:02.0 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
> Network Controller (Virtual Function) (rev 21)
> # echo 0000:7d:01.6 > /sys/bus/pci/devices/0000:7d:01.6/driver/unbind

Do you know if the bug occurred on 5.4? Is this the correct fixes tag?

Fixes: 862d969a3a4d ("net: hns3: do VF's pci re-initialization while PF doing FLR")

2020-10-27 13:57:54

by Yunsheng Lin

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On 2020/10/27 7:13, Jakub Kicinski wrote:
> On Fri, 23 Oct 2020 15:01:14 +0800 Zenghui Yu wrote:
>> On 2020/10/23 14:22, Yunsheng Lin wrote:
>>> On 2020/10/23 13:15, Zenghui Yu wrote:
>>>> When unbinding the hns3 driver with the HNS3 VF, I got the following
>>>> kernel panic:
>>>>
>>>> [ 265.709989] Unable to handle kernel paging request at virtual address ffff800054627000
>>>> [ 265.717928] Mem abort info:
>>>> [ 265.720740] ESR = 0x96000047
>>>> [ 265.723810] EC = 0x25: DABT (current EL), IL = 32 bits
>>>> [ 265.729126] SET = 0, FnV = 0
>>>> [ 265.732195] EA = 0, S1PTW = 0
>>>> [ 265.735351] Data abort info:
>>>> [ 265.738227] ISV = 0, ISS = 0x00000047
>>>> [ 265.742071] CM = 0, WnR = 1
>>>> [ 265.745055] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000009b54000
>>>> [ 265.751753] [ffff800054627000] pgd=0000202ffffff003, p4d=0000202ffffff003, pud=00002020020eb003, pmd=00000020a0dfc003, pte=0000000000000000
>>>> [ 265.764314] Internal error: Oops: 96000047 [#1] SMP
>>>> [ 265.830357] CPU: 61 PID: 20319 Comm: bash Not tainted 5.9.0+ #206
>>>> [ 265.836423] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 1.05 09/18/2019
>>>
>>> Do you care to provide the testcase for above calltrace?
>>
>> I noticed it with VFIO, but it's easy to reproduce it manually. Here you
>> go:
>>
>> # cat /sys/bus/pci/devices/0000\:7d\:00.2/sriov_totalvfs
>> 3
>> # echo 3 > /sys/bus/pci/devices/0000\:7d\:00.2/sriov_numvfs
>> # lspci | grep "Virtual Function"
>> 7d:01.6 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
>> Network Controller (Virtual Function) (rev 21)
>> 7d:01.7 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
>> Network Controller (Virtual Function) (rev 21)
>> 7d:02.0 Ethernet controller: Huawei Technologies Co., Ltd. HNS RDMA
>> Network Controller (Virtual Function) (rev 21)
>> # echo 0000:7d:01.6 > /sys/bus/pci/devices/0000:7d:01.6/driver/unbind
>
> Do you know if the bug occurred on 5.4? Is this the correct fixes tag?
>
> Fixes: 862d969a3a4d ("net: hns3: do VF's pci re-initialization while PF doing FLR")

The correct Fixes tag should be:

Fixes: e3338205f0c7 ("net: hns3: uninitialize pci in the hclgevf_uninit")

Thanks

>
> .
>

2020-10-27 14:06:09

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On Tue, 27 Oct 2020 09:42:01 +0800 Yunsheng Lin wrote:
> On 2020/10/27 9:25, Jakub Kicinski wrote:
> > On Tue, 27 Oct 2020 09:24:10 +0800 Yunsheng Lin wrote:
> >>> Fixes: 862d969a3a4d ("net: hns3: do VF's pci re-initialization while PF doing FLR")
> >>
> >> The correct Fixes tag should be:
> >>
> >> Fixes: e3338205f0c7 ("net: hns3: uninitialize pci in the hclgevf_uninit")
> >
> > Why is that?
> >
> > Isn't the issue the order of cmd vs pci calls? e3338205f0c7 only takes
> > the pci call from under an if, the order was wrong before.
>
> You are right, the e3338205f0c7 only add the missing hclgevf_pci_uninit()
> when HCLGEVF_STATE_IRQ_INITED is not set.
>
> So I think the tag you provided is correct, thanks.

Great, added the tag and applied, thanks!

2020-10-27 19:49:27

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On Tue, 27 Oct 2020 09:24:10 +0800 Yunsheng Lin wrote:
> > Fixes: 862d969a3a4d ("net: hns3: do VF's pci re-initialization while PF doing FLR")
>
> The correct Fixes tag should be:
>
> Fixes: e3338205f0c7 ("net: hns3: uninitialize pci in the hclgevf_uninit")

Why is that?

Isn't the issue the order of cmd vs pci calls? e3338205f0c7 only takes
the pci call from under an if, the order was wrong before.

2020-10-27 19:49:27

by Yunsheng Lin

[permalink] [raw]
Subject: Re: [PATCH net] net: hns3: Clear the CMDQ registers before unmapping BAR region

On 2020/10/27 9:25, Jakub Kicinski wrote:
> On Tue, 27 Oct 2020 09:24:10 +0800 Yunsheng Lin wrote:
>>> Fixes: 862d969a3a4d ("net: hns3: do VF's pci re-initialization while PF doing FLR")
>>
>> The correct Fixes tag should be:
>>
>> Fixes: e3338205f0c7 ("net: hns3: uninitialize pci in the hclgevf_uninit")
>
> Why is that?
>
> Isn't the issue the order of cmd vs pci calls? e3338205f0c7 only takes
> the pci call from under an if, the order was wrong before.

You are right, the e3338205f0c7 only add the missing hclgevf_pci_uninit()
when HCLGEVF_STATE_IRQ_INITED is not set.

So I think the tag you provided is correct, thanks.

> .
>