Hi James, Thanks for reviewing the patch. On 2020/10/1 21:44, James Morse wrote: > Hi Tanxiaofei, > > (sorry for the late reply) > > On 28/09/2020 03:02, Xiaofei Tan wrote: >> After the commit 8fcc4ae6faf8 ("arm64: acpi: Make apei_claim_sea() >> synchronise with APEI's irq work") applied, do_sea() return directly >> for user-mode if apei_claim_sea() handled any error record. Therefore, >> each error record reported by the user-mode SEA must be effectively >> processed in APEI GHES driver. >> >> Currently, GHES driver only processes Memory Error Section.(Ignore PCIe >> Error Section, as it has nothing to do with SEA). It is not enough. >> Because ARM Processor Error could also be used for SEA in some hardware >> platforms, such as Kunpeng9xx series. We can't ask them to switch to >> use Memory Error Section for two reasons: >> 1)The server was delivered to customers, and it will introduce >> compatibility issue. > >> 2)It make sense to use ARM Processor Error Section. Because either >> cache or memory errors could generate SEA when consumed by a processor. >> >> Do memory failure handling for ARM Processor Error Section just like >> for Memory Error Section. > > >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c >> index 99df00f..ca0aa97 100644 >> --- a/drivers/acpi/apei/ghes. >> +++ b/drivers/acpi/apei/ghes.c >> @@ -441,28 +441,35 @@ static void ghes_kick_task_work(struct callback_head >> *head) > >> +static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, >> int sev) >> +{ >> + struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata); >> + struct cper_arm_err_info *err_info; >> + bool queued = false; >> + int sec_sev, i; >> + >> + log_arm_hw_error(err); >> + >> + sec_sev = ghes_severity(gdata->error_severity); >> + if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE) >> + return false; >> + >> + err_info = (struct cper_arm_err_info *) (err + 1); >> + for (i = 0; i < err->err_info_num; i++, err_info++) { > > err_info has its own length, could we use that in case someone comes up with > a new table > version? (like this, old versions of the kernel will read mis-aligned > structures) >
The length of err_info is hard written in "ARM Processor Error Section", always 32 bytes. If someone comes up with a new table version, must also be this length. It seems no much differences to change to use the fixed 32 bytes here. > >> + if (!(err_info->validation_bits & >> CPER_ARM_INFO_VALID_PHYSICAL_ADDR)) >> + continue; >> + >> + if (err_info->type != CPER_ARM_CACHE_ERROR) { >> + pr_warn_ratelimited(FW_WARN GHES_PFX >> + "Physical address should be invalid for %s\n", > > Should? A bus-error could have a valid physical address. I can't see anything > in the spec > that forbids this. Really? Our platform can't physical address for bus-error. I remember you asked this in earlier version patch, which is why i skipped non-cache error. In general we shouldn't try to validate what firmware is doing. > > >> + err_info->type < ARRAY_SIZE(cper_proc_error_type_strs) ? >> + cper_proc_error_type_strs[err_info->type] : "unknown >> error type"); >> + continue; >> + } > > I think we should warn for the cases this handler doesn't cover, but we > should try to > catch all of them. e.g: > > | bool is_cache = (err_info->type == CPER_ARM_CACHE_ERROR); > | bool has_pa = (err_info->validation_bits & > CPER_ARM_INFO_VALID_PHYSICAL_ADDR) > | > | if (!is_cache || !has_pa) { > | pr_warn_ratelimited(..."Unhandled processor error type %s\n", > ...); > | continue; > | } > OK > > For cache errors, (err_info->error_info & BIT(26)) has its own > corrected/uncorrected flag. > You filter out 'overall corrected' section types earlier, could you check > this error > record before invoking memory_failure()? > Do you mean skip corrected error in a recoverable or fatal error section ? We only use the severity type of section header, and this corrected/uncorrected flag may not be filled correctly in firmware. > (sections may contain a set of errors. I'm not convinced a 'corrected > section' can't > contain latent uncorrected errors, it just means the machine didn't need that > data yet) > If contain uncorrected errors, then the error section should be defined as recoverable. > > >> + if (ghes_do_memory_failure(err_info->physical_fault_addr, 0)) >> + queued = true; > > May as well: > | return ghes_do_memory_failure(...); > We can't return directly from here, as other error info may not have been handled. > >> + } >> + >> + return queued; > > (and make this: > | return false > ) > >> +} > > > > Thanks, > > James > > . > -- thanks tanxiaofei