From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4167DC433E7 for ; Fri, 9 Oct 2020 08:20:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA56522247 for ; Fri, 9 Oct 2020 08:20:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732570AbgJIIUe (ORCPT ); Fri, 9 Oct 2020 04:20:34 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:15199 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732547AbgJIIUe (ORCPT ); Fri, 9 Oct 2020 04:20:34 -0400 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 1AED2D3E59D5D3204E6D; Fri, 9 Oct 2020 16:20:31 +0800 (CST) Received: from [127.0.0.1] (10.74.185.4) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Fri, 9 Oct 2020 16:20:25 +0800 Subject: Re: [PATCH v3] ACPI / APEI: do memory failure on the physical address reported by ARM processor error section To: James Morse References: <1601258560-6658-1-git-send-email-tanxiaofei@huawei.com> <06ebead0-ffa5-5003-f0a7-0b38fcb0e702@arm.com> CC: , , , , , , , , , , From: Xiaofei Tan Message-ID: <5F801D49.302@huawei.com> Date: Fri, 9 Oct 2020 16:20:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <06ebead0-ffa5-5003-f0a7-0b38fcb0e702@arm.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.74.185.4] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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