Re: [PATCH v6 3/5] PCI/AER: Report fatal errors of RCiEP and EP if link recoverd

[Shuai Xue <xueshuai@linux.alibaba.com>]

在 2025/10/21 02:38, Kuppuswamy Sathyanarayanan 写道:
> 
> On 10/14/25 19:41, Shuai Xue wrote:
>> The AER driver has historically avoided reading the configuration space of
>> an endpoint or RCiEP that reported a fatal error, considering the link to
>> that device unreliable. Consequently, when a fatal error occurs, the AER
>> and DPC drivers do not report specific error types, resulting in logs like:
>>
>>    pcieport 0015:00:00.0: EDR: EDR event received
>>    pcieport 0015:00:00.0: EDR: Reported EDR dev: 0015:00:00.0
>>    pcieport 0015:00:00.0: DPC: containment event, status:0x200d, ERR_FATAL received from 0015:01:00.0
>>    pcieport 0015:00:00.0: AER: broadcast error_detected message
>>    pcieport 0015:00:00.0: AER: broadcast mmio_enabled message
>>    pcieport 0015:00:00.0: AER: broadcast resume message
>>    pcieport 0015:00:00.0: pciehp: Slot(21): Link Down/Up ignored
>>    pcieport 0015:00:00.0: AER: device recovery successful
>>    pcieport 0015:00:00.0: EDR: DPC port successfully recovered
>>    pcieport 0015:00:00.0: EDR: Status for 0015:00:00.0: 0x80
>>
>> AER status registers are sticky and Write-1-to-clear. If the link recovered
>> after hot reset, we can still safely access AER status and TLP header of the
>> error device. In such case, report fatal errors which helps to figure out the
>> error root case.
>>
>> After this patch, the logs like:
>>
>>    pcieport 0015:00:00.0: EDR: EDR event received
>>    pcieport 0015:00:00.0: EDR: Reported EDR dev: 0015:00:00.0
>>    pcieport 0015:00:00.0: DPC: containment event, status:0x200d, ERR_FATAL received from 0015:01:00.0
>>    pcieport 0015:00:00.0: AER: broadcast error_detected message
>>    vfio-pci 0015:01:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), type=Transaction Layer, (Receiver ID)
>>    pcieport 0015:00:00.0: pciehp: Slot(21): Link Down/Up ignored
> 
> It would be more clear if you follow the same order of the log as before section
> and highlight the new logs that are getting added.

I see. I will reorder the pciehp log.

> 
>>    vfio-pci 0015:01:00.0:   device [144d:a80a] error status/mask=00001000/00400000
>>    vfio-pci 0015:01:00.0:    [12] TLP                    (First)
>>    vfio-pci 0015:01:00.0: AER:   TLP Header: 0x4a004010 0x00000040 0x01000000 0xffffffff
>>    pcieport 0015:00:00.0: AER: broadcast mmio_enabled message
>>    pcieport 0015:00:00.0: AER: broadcast resume message
>>    pcieport 0015:00:00.0: AER: device recovery successful
>>    pcieport 0015:00:00.0: EDR: DPC port successfully recovered
>>    pcieport 0015:00:00.0: EDR: Status for 0015:00:00.0: 0x80
>>
>> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
>> ---
>>   drivers/pci/pci.h      |  4 +++-
>>   drivers/pci/pcie/aer.c | 18 +++++++++++-------
>>   drivers/pci/pcie/dpc.c |  2 +-
>>   drivers/pci/pcie/err.c | 11 +++++++++++
>>   4 files changed, 26 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>> index 6b0c55bed15b..3eccef2d25a3 100644
>> --- a/drivers/pci/pci.h
>> +++ b/drivers/pci/pci.h
>> @@ -739,8 +739,10 @@ struct aer_err_info {
>>       struct pcie_tlp_log tlp;    /* TLP Header */
>>   };
>> -int aer_get_device_error_info(struct aer_err_info *info, int i);
>> +int aer_get_device_error_info(struct aer_err_info *info, int i,
>> +                  bool link_healthy);
>>   void aer_print_error(struct aer_err_info *info, int i);
>> +int aer_add_error_device(struct aer_err_info *e_info, struct pci_dev *dev);
>>   int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
>>                 unsigned int tlp_len, bool flit,
>> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
>> index 0b5ed4722ac3..aaea9902cbb7 100644
>> --- a/drivers/pci/pcie/aer.c
>> +++ b/drivers/pci/pcie/aer.c
>> @@ -978,7 +978,7 @@ EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
>>    * @e_info: pointer to error info
>>    * @dev: pointer to pci_dev to be added
>>    */
>> -static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
>> +int aer_add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
> 
> I don't think you need this rename.

Yep, will rename back.

> 
>>   {
>>       int i = e_info->error_dev_num;
>> @@ -1068,7 +1068,7 @@ static int find_device_iter(struct pci_dev *dev, void *data)
>>       if (is_error_source(dev, e_info)) {
>>           /* List this device */
>> -        if (add_error_device(e_info, dev)) {
>> +        if (aer_add_error_device(e_info, dev)) {
>>               /* We cannot handle more... Stop iteration */
>>               pci_err(dev, "Exceeded max supported (%d) devices with errors logged\n",
>>                   AER_MAX_MULTI_ERR_DEVICES);
>> @@ -1382,12 +1382,14 @@ EXPORT_SYMBOL_GPL(aer_recover_queue);
>>    * aer_get_device_error_info - read error status from dev and store it to info
>>    * @info: pointer to structure to store the error record
>>    * @i: index into info->dev[]
>> + * @link_healthy: link is healthy or not
>>    *
>>    * Return: 1 on success, 0 on error.
>>    *
>>    * Note that @info is reused among all error devices. Clear fields properly.
>>    */
>> -int aer_get_device_error_info(struct aer_err_info *info, int i)
>> +int aer_get_device_error_info(struct aer_err_info *info, int i,
>> +                  bool link_healthy)
>>   {
>>       struct pci_dev *dev;
>>       int type, aer;
>> @@ -1415,10 +1417,12 @@ int aer_get_device_error_info(struct aer_err_info *info, int i)
>>               &info->mask);
>>           if (!(info->status & ~info->mask))
>>               return 0;
>> +        info->level = KERN_WARNING;
> 
> I recommend setting this when initializing the info->level at the caller end (to match
> other callers)

Good point, will drop this changes.

> 
>>       } else if (type == PCI_EXP_TYPE_ROOT_PORT ||
>>              type == PCI_EXP_TYPE_RC_EC ||
>>              type == PCI_EXP_TYPE_DOWNSTREAM ||
>> -           info->severity == AER_NONFATAL) {
>> +           info->severity == AER_NONFATAL ||
>> +           (info->severity == AER_FATAL && link_healthy)) {
>>           /* Link is still healthy for IO reads */
>>           pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
>> @@ -1427,7 +1431,7 @@ int aer_get_device_error_info(struct aer_err_info *info, int i)
>>               &info->mask);
>>           if (!(info->status & ~info->mask))
>>               return 0;
>> -
>> +        info->level = KERN_ERR;
>>           /* Get First Error Pointer */
>>           pci_read_config_dword(dev, aer + PCI_ERR_CAP, &aercc);
>>           info->first_error = PCI_ERR_CAP_FEP(aercc);
>> @@ -1451,11 +1455,11 @@ static inline void aer_process_err_devices(struct aer_err_info *e_info)
>>       /* Report all before handling them, to not lose records by reset etc. */
>>       for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
>> -        if (aer_get_device_error_info(e_info, i))
>> +        if (aer_get_device_error_info(e_info, i, false))
>>               aer_print_error(e_info, i);
>>       }
>>       for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
>> -        if (aer_get_device_error_info(e_info, i))
>> +        if (aer_get_device_error_info(e_info, i, false))
>>               handle_error_source(e_info->dev[i], e_info);
>>       }
>>   }
>> diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
>> index f6069f621683..21c4e8371279 100644
>> --- a/drivers/pci/pcie/dpc.c
>> +++ b/drivers/pci/pcie/dpc.c
>> @@ -284,7 +284,7 @@ struct pci_dev *dpc_process_error(struct pci_dev *pdev)
>>           pci_warn(pdev, "containment event, status:%#06x: unmasked uncorrectable error detected\n",
>>                status);
>>           if (dpc_get_aer_uncorrect_severity(pdev, &info) &&
>> -            aer_get_device_error_info(&info, 0)) {
>> +            aer_get_device_error_info(&info, 0, false)) {
>>               aer_print_error(&info, 0);
>>               pci_aer_clear_nonfatal_status(pdev);
>>               pci_aer_clear_fatal_status(pdev);
>> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
>> index bebe4bc111d7..4e65eac809d1 100644
>> --- a/drivers/pci/pcie/err.c
>> +++ b/drivers/pci/pcie/err.c
>> @@ -215,6 +215,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>>       struct pci_dev *bridge;
>>       pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
>>       struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
>> +    struct aer_err_info info;
>>       /*
>>        * If the error was detected by a Root Port, Downstream Port, RCEC,
>> @@ -253,6 +254,16 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>>               pci_warn(bridge, "subordinate device reset failed\n");
>>               goto failed;
>>           }
>> +
>> +        /* Link recovered, report fatal errors of RCiEP or EP */
>> +        if (state == pci_channel_io_frozen &&
>> +            (type == PCI_EXP_TYPE_ENDPOINT || type == PCI_EXP_TYPE_RC_END)) {
>> +            aer_add_error_device(&info, dev);
>> +            info.severity = AER_FATAL;
> info.level = KERN_ERR ?

Yep, will set level in caller site.

>> +            if (aer_get_device_error_info(&info, 0, true))
>> +                aer_print_error(&info, 0);
>> +            pci_dev_put(dev);
> 
> Like Lukas mentioned, it needs a comment about why you need this.
> 

Sure, will add it.

Thanks.
Shuai