On Mon, 19 May 2025, Bjorn Helgaas wrote: > From: Jon Pan-Doh <pan...@google.com> > > Allow userspace to read/write log ratelimits per device (including > enable/disable). Create aer/ sysfs directory to store them and any > future aer configs. > > Update AER sysfs ABI filename to reflect the broader scope of AER sysfs > attributes (e.g. stats and ratelimits). > > Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats -> > sysfs-bus-pci-devices-aer > > Tested using aer-inject[1]. Configured correctable log ratelimit to 5. > Sent 6 AER errors. Observed 5 errors logged while AER stats > (cat /sys/bus/pci/devices/<dev>/aer_dev_correctable) shows 6. > > Disabled ratelimiting and sent 6 more AER errors. Observed all 6 errors > logged and accounted in AER stats (12 total errors). > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git > > Signed-off-by: Karolina Stolarek <karolina.stola...@oracle.com> > Signed-off-by: Jon Pan-Doh <pan...@google.com> > Signed-off-by: Bjorn Helgaas <bhelg...@google.com> > Acked-by: Paul E. McKenney <paul...@kernel.org> > --- > ...es-aer_stats => sysfs-bus-pci-devices-aer} | 34 +++++++ > Documentation/PCI/pcieaer-howto.rst | 5 +- > drivers/pci/pci-sysfs.c | 1 + > drivers/pci/pci.h | 1 + > drivers/pci/pcie/aer.c | 99 +++++++++++++++++++ > 5 files changed, 139 insertions(+), 1 deletion(-) > rename Documentation/ABI/testing/{sysfs-bus-pci-devices-aer_stats => > sysfs-bus-pci-devices-aer} (77%) > > diff --git a/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats > b/Documentation/ABI/testing/sysfs-bus-pci-devices-aer > similarity index 77% > rename from Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats > rename to Documentation/ABI/testing/sysfs-bus-pci-devices-aer > index d1f67bb81d5d..771204197b71 100644 > --- a/Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats > +++ b/Documentation/ABI/testing/sysfs-bus-pci-devices-aer > @@ -117,3 +117,37 @@ Date: July 2018 > KernelVersion: 4.19.0 > Contact: linux-...@vger.kernel.org, raja...@google.com > Description: Total number of ERR_NONFATAL messages reported to rootport. > + > +PCIe AER ratelimits > +------------------- > + > +These attributes show up under all the devices that are AER capable. > +They represent configurable ratelimits of logs per error type. > + > +See Documentation/PCI/pcieaer-howto.rst for more info on ratelimits. > + > +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_log_enable > +Date: March 2025 > +KernelVersion: 6.15.0
This ship has sailed. > +Contact: linux-...@vger.kernel.org, pan...@google.com > +Description: Writing 1/0 enables/disables AER log ratelimiting. Reading > + gets whether or not AER is currently enabled. AER or AER ratelimiting is enabled? > + Enabled by > + default. > + > +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_burst_cor_log > +Date: March 2025 > +KernelVersion: 6.15.0 > +Contact: linux-...@vger.kernel.org, pan...@google.com > +Description: Ratelimit burst for correctable error logs. Writing a value > + changes the number of errors (burst) allowed per interval > + (5 second window) before ratelimiting. Reading gets the > + current ratelimit burst. > + > +What: /sys/bus/pci/devices/<dev>/aer/ratelimit_burst_uncor_log > +Date: March 2025 > +KernelVersion: 6.15.0 > +Contact: linux-...@vger.kernel.org, pan...@google.com > +Description: Ratelimit burst for uncorrectable error logs. Writing a > + value changes the number of errors (burst) allowed per > + interval (5 second window) before ratelimiting. Reading > + gets the current ratelimit burst. > diff --git a/Documentation/PCI/pcieaer-howto.rst > b/Documentation/PCI/pcieaer-howto.rst > index 896d2a232a90..043cdb3194be 100644 > --- a/Documentation/PCI/pcieaer-howto.rst > +++ b/Documentation/PCI/pcieaer-howto.rst > @@ -96,12 +96,15 @@ type (correctable vs. uncorrectable). > AER uses the default ratelimit of DEFAULT_RATELIMIT_BURST (10 events) over > DEFAULT_RATELIMIT_INTERVAL (5 seconds). > > +Ratelimits are exposed in the form of sysfs attributes and configurable. > +See Documentation/ABI/testing/sysfs-bus-pci-devices-aer. > + > AER Statistics / Counters > ------------------------- > > When PCIe AER errors are captured, the counters / statistics are also exposed > in the form of sysfs attributes which are documented at > -Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats > +Documentation/ABI/testing/sysfs-bus-pci-devices-aer. > > Developer Guide > =============== > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index c6cda56ca52c..278de99b00ce 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -1805,6 +1805,7 @@ const struct attribute_group *pci_dev_attr_groups[] = { > &pcie_dev_attr_group, > #ifdef CONFIG_PCIEAER > &aer_stats_attr_group, > + &aer_attr_group, > #endif > #ifdef CONFIG_PCIEASPM > &aspm_ctrl_attr_group, > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 65c466279ade..a3261e842d6d 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -963,6 +963,7 @@ void pci_no_aer(void); > void pci_aer_init(struct pci_dev *dev); > void pci_aer_exit(struct pci_dev *dev); > extern const struct attribute_group aer_stats_attr_group; > +extern const struct attribute_group aer_attr_group; > void pci_aer_clear_fatal_status(struct pci_dev *dev); > int pci_aer_clear_status(struct pci_dev *dev); > int pci_aer_raw_clear_status(struct pci_dev *dev); > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > index c335e0bb9f51..42df5cb963b3 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -627,6 +627,105 @@ const struct attribute_group aer_stats_attr_group = { > .is_visible = aer_stats_attrs_are_visible, > }; > > +/* > + * Ratelimit enable toggle > + * 0: disabled with ratelimit.interval = 0 > + * 1: enabled with ratelimit.interval = nonzero > + */ > +static ssize_t ratelimit_log_enable_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + bool enabled = pdev->aer_report->cor_log_ratelimit.interval != 0; > + > + return sysfs_emit(buf, "%d\n", enabled); > +} > + > +static ssize_t ratelimit_log_enable_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + bool enable; > + int interval; > + > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > + if (kstrtobool(buf, &enable) < 0) > + return -EINVAL; > + > + if (enable) > + interval = DEFAULT_RATELIMIT_INTERVAL; > + else > + interval = 0; > + > + pdev->aer_report->cor_log_ratelimit.interval = interval; > + pdev->aer_report->uncor_log_ratelimit.interval = interval; > + > + return count; > +} > +static DEVICE_ATTR_RW(ratelimit_log_enable); > + > +#define aer_ratelimit_burst_attr(name, ratelimit) \ > + static ssize_t \ > + name##_show(struct device *dev, struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + struct pci_dev *pdev = to_pci_dev(dev); \ > + \ > + return sysfs_emit(buf, "%d\n", \ > + pdev->aer_report->ratelimit.burst); \ > +} \ > + \ > + static ssize_t \ > + name##_store(struct device *dev, struct device_attribute *attr, \ > + const char *buf, size_t count) \ > +{ \ > + struct pci_dev *pdev = to_pci_dev(dev); \ > + int burst; \ > + \ > + if (!capable(CAP_SYS_ADMIN)) \ > + return -EPERM; \ > + \ > + if (kstrtoint(buf, 0, &burst) < 0) \ > + return -EINVAL; \ > + \ > + pdev->aer_report->ratelimit.burst = burst; \ > + \ > + return count; \ > +} \ > +static DEVICE_ATTR_RW(name) > + > +aer_ratelimit_burst_attr(ratelimit_burst_cor_log, cor_log_ratelimit); > +aer_ratelimit_burst_attr(ratelimit_burst_uncor_log, uncor_log_ratelimit); > + > +static struct attribute *aer_attrs[] = { > + &dev_attr_ratelimit_log_enable.attr, > + &dev_attr_ratelimit_burst_cor_log.attr, > + &dev_attr_ratelimit_burst_uncor_log.attr, > + NULL > +}; > + > +static umode_t aer_attrs_are_visible(struct kobject *kobj, > + struct attribute *a, int n) > +{ > + struct device *dev = kobj_to_dev(kobj); > + struct pci_dev *pdev = to_pci_dev(dev); > + > + if (!pdev->aer_report) > + return 0; > + > + return a->mode; > +} > + > +const struct attribute_group aer_attr_group = { > + .name = "aer", > + .attrs = aer_attrs, > + .is_visible = aer_attrs_are_visible, > +}; > + > static void pci_dev_aer_stats_incr(struct pci_dev *pdev, > struct aer_err_info *info) > { > -- i.