Hi, On 1/23/2026 11:45 PM, 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: AER: Errors reported prior to reset > + vfio-pci 0015:01:00.0: PCIe Bus Error: severity=Uncorrectable (Fatal), > type=Transaction Layer, (Receiver ID) > + 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: 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 > > Signed-off-by: Shuai Xue <[email protected]> > ---
LGTM. Few suggestions inline. Reviewed-by: Kuppuswamy Sathyanarayanan <[email protected]> > drivers/pci/pci.h | 4 +++- > drivers/pci/pcie/aer.c | 32 ++++++++++++++++++++++++++++---- > drivers/pci/pcie/dpc.c | 2 +- > drivers/pci/pcie/err.c | 5 +++++ > 4 files changed, 37 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 58640e656897..bd020ba0cef0 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -746,8 +746,10 @@ 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); > +void aer_report_frozen_error(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 e0bcaa896803..4c0a2bbe9197 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -1384,12 +1384,14 @@ 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; > @@ -1420,7 +1422,8 @@ int aer_get_device_error_info(struct aer_err_info > *info, int i) > } 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, > @@ -1447,17 +1450,38 @@ int aer_get_device_error_info(struct aer_err_info > *info, int i) > return 1; > } > > +void aer_report_frozen_error(struct pci_dev *dev) Since this function focuses specifically on printing fatal error details, would aer_print_fatal_error() be a more descriptive name? > +{ > + struct aer_err_info info; > + int type = pci_pcie_type(dev); > + > + if (type != PCI_EXP_TYPE_ENDPOINT && type != PCI_EXP_TYPE_RC_END) > + return; > + > + info.error_dev_num = 0; > + info.severity = AER_FATAL; > + info.level = KERN_ERR; > + add_error_device(&info, dev); > + > + if (aer_get_device_error_info(&info, 0, true)) { > + pci_err(dev, "Errors reported prior to reset\n"); The 'prior to reset' context depends on where this is called. I'd suggest moving this log to the caller or removing it entirely to keep this helper generic. > + aer_print_error(&info, 0); > + } > + > + pci_dev_put(dev); /* pairs with pci_dev_get() in add_error_device() */ > +} > + > static inline void aer_process_err_devices(struct aer_err_info *e_info) > { > int i; > > /* 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..0780ea09478b 100644 > --- a/drivers/pci/pcie/err.c > +++ b/drivers/pci/pcie/err.c > @@ -253,6 +253,11 @@ 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) To align with your comment regarding RCiEPs and EPs, should we explicitly validate the device type here before calling the report function? > + aer_report_frozen_error(dev); > + > } > > if (status == PCI_ERS_RESULT_NEED_RESET) { -- Sathyanarayanan Kuppuswamy Linux Kernel Developer
