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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18026CDB474 for ; Tue, 17 Oct 2023 21:25:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344277AbjJQVZ4 (ORCPT ); Tue, 17 Oct 2023 17:25:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344398AbjJQVZQ (ORCPT ); Tue, 17 Oct 2023 17:25:16 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55FD019BA for ; Tue, 17 Oct 2023 14:24:06 -0700 (PDT) Message-ID: <20231017211723.632681010@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1697577845; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=QjcerSYtQUE8Lx8f8JosHi9f4nt1WbYnOT38iwWvnnc=; b=p1msP50Atm24FvpHP62M2qSOfw2vX1H24wsJIUbg2sA00W/wxWBoXZ4yyATt6XAp/Xb0V5 kmrRcWDBLxbeijgu0X1QwLHt2Tfe3KNR5ag4q0BlwSJ1wIEuaJHJ9w8aeRiyUDP7PmdCDJ l250IeosqCJJH4mPVh5Bg6n+gftrcxbQHLG5cU1f4A5Do9pCitrkH4LRJMjXIULlPJ8KA9 SZQa+CzC9eBXmk30m3lZQmI21PfUnsn3SCkMnT188kImbThkjmQMJogVWpM0ujKNFiZn2g +fSJRBinKgujSGLTLN8h8r/8vpVSlpJ8a7NOK+ZFlWpxmr2Dvy77XNx7kxS7pQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1697577845; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=QjcerSYtQUE8Lx8f8JosHi9f4nt1WbYnOT38iwWvnnc=; b=p/EWCrJO7nlfRm2zqjZe6c91DGTSlJ4H1+3eg0YdYho5ReBb99TPeyLd/i09Q9bxGEVqEx fcHC/VNHefZyGpCQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Borislav Petkov Subject: [patch V5 30/39] x86/microcode: Add per CPU result state References: <20231017200758.877560658@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Tue, 17 Oct 2023 23:24:05 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner The microcode rendezvous is purely acting on global state, which does not allow to analyze fails in a coherent way. Introduce per CPU state where the results are written into, which allows to analyze the return codes of the individual CPUs. Initialize the state when walking the cpu_present_mask in the online check to avoid another for_each_cpu() loop. Enhance the result print out with that. The structure is intentionally named ucode_ctrl as it will gain control fields in subsequent changes. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/microcode/core.c | 112 ++++++++++++++++++------------- arch/x86/kernel/cpu/microcode/internal.h | 1 2 files changed, 67 insertions(+), 46 deletions(-) --- --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -252,6 +252,11 @@ static struct platform_device *microcode * requirement can be relaxed in the future. Right now, this is conservative * and good. */ +struct microcode_ctrl { + enum ucode_state result; +}; + +static DEFINE_PER_CPU(struct microcode_ctrl, ucode_ctrl); static atomic_t late_cpus_in, late_cpus_out; static bool wait_for_cpus(atomic_t *cnt) @@ -274,23 +279,19 @@ static bool wait_for_cpus(atomic_t *cnt) return false; } -/* - * Returns: - * < 0 - on error - * 0 - success (no update done or microcode was updated) - */ -static int __reload_late(void *info) +static int load_cpus_stopped(void *unused) { int cpu = smp_processor_id(); - enum ucode_state err; - int ret = 0; + enum ucode_state ret; /* * Wait for all CPUs to arrive. A load will not be attempted unless all * CPUs show up. * */ - if (!wait_for_cpus(&late_cpus_in)) - return -1; + if (!wait_for_cpus(&late_cpus_in)) { + this_cpu_write(ucode_ctrl.result, UCODE_TIMEOUT); + return 0; + } /* * On an SMT system, it suffices to load the microcode on one sibling of @@ -299,17 +300,11 @@ static int __reload_late(void *info) * loading attempts happen on multiple threads of an SMT core. See * below. */ - if (cpumask_first(topology_sibling_cpumask(cpu)) == cpu) - err = microcode_ops->apply_microcode(cpu); - else + if (cpumask_first(topology_sibling_cpumask(cpu)) != cpu) goto wait_for_siblings; - if (err >= UCODE_NFOUND) { - if (err == UCODE_ERROR) { - pr_warn("Error reloading microcode on CPU %d\n", cpu); - ret = -1; - } - } + ret = microcode_ops->apply_microcode(cpu); + this_cpu_write(ucode_ctrl.result, ret); wait_for_siblings: if (!wait_for_cpus(&late_cpus_out)) @@ -321,19 +316,18 @@ static int __reload_late(void *info) * per-cpu cpuinfo can be updated with right microcode * revision. */ - if (cpumask_first(topology_sibling_cpumask(cpu)) != cpu) - err = microcode_ops->apply_microcode(cpu); + if (cpumask_first(topology_sibling_cpumask(cpu)) == cpu) + return 0; - return ret; + ret = microcode_ops->apply_microcode(cpu); + this_cpu_write(ucode_ctrl.result, ret); + return 0; } -/* - * Reload microcode late on all CPUs. Wait for a sec until they - * all gather together. - */ -static int microcode_reload_late(void) +static int load_late_stop_cpus(void) { - int old = boot_cpu_data.microcode, ret; + unsigned int cpu, updated = 0, failed = 0, timedout = 0, siblings = 0; + int old_rev = boot_cpu_data.microcode; struct cpuinfo_x86 prev_info; pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n"); @@ -348,26 +342,47 @@ static int microcode_reload_late(void) */ store_cpu_caps(&prev_info); - ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask); + stop_machine_cpuslocked(load_cpus_stopped, NULL, cpu_online_mask); + + /* Analyze the results */ + for_each_cpu_and(cpu, cpu_present_mask, &cpus_booted_once_mask) { + switch (per_cpu(ucode_ctrl.result, cpu)) { + case UCODE_UPDATED: updated++; break; + case UCODE_TIMEOUT: timedout++; break; + case UCODE_OK: siblings++; break; + default: failed++; break; + } + } if (microcode_ops->finalize_late_load) - microcode_ops->finalize_late_load(ret); + microcode_ops->finalize_late_load(!updated); - if (!ret) { - pr_info("Reload succeeded, microcode revision: 0x%x -> 0x%x\n", - old, boot_cpu_data.microcode); - microcode_check(&prev_info); - add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); - } else { - pr_info("Reload failed, current microcode revision: 0x%x\n", - boot_cpu_data.microcode); + if (!updated) { + /* Nothing changed. */ + if (!failed && !timedout) + return 0; + pr_err("update failed: %u CPUs failed %u CPUs timed out\n", + failed, timedout); + return -EIO; } - return ret; + + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + pr_info("load: updated on %u primary CPUs with %u siblings\n", updated, siblings); + if (failed || timedout) { + pr_err("load incomplete. %u CPUs timed out or failed\n", + num_online_cpus() - (updated + siblings)); + } + pr_info("revision: 0x%x -> 0x%x\n", old_rev, boot_cpu_data.microcode); + microcode_check(&prev_info); + + return updated + siblings == num_online_cpus() ? 0 : -EIO; } /* - * Ensure that all required CPUs which are present and have been booted - * once are online. + * This function does two things: + * + * 1) Ensure that all required CPUs which are present and have been booted + * once are online. * * To pass this check, all primary threads must be online. * @@ -378,9 +393,12 @@ static int microcode_reload_late(void) * behaviour is undefined. The default play_dead() implementation on * modern CPUs uses MWAIT, which is also not guaranteed to be safe * against a microcode update which affects MWAIT. + * + * 2) Initialize the per CPU control structure */ -static bool ensure_cpus_are_online(void) +static bool setup_cpus(void) { + struct microcode_ctrl ctrl = { .result = -1, }; unsigned int cpu; for_each_cpu_and(cpu, cpu_present_mask, &cpus_booted_once_mask) { @@ -390,18 +408,20 @@ static bool ensure_cpus_are_online(void) return false; } } + /* Initialize the per CPU state */ + per_cpu(ucode_ctrl, cpu) = ctrl; } return true; } -static int ucode_load_late_locked(void) +static int load_late_locked(void) { - if (!ensure_cpus_are_online()) + if (!setup_cpus()) return -EBUSY; switch (microcode_ops->request_microcode_fw(0, µcode_pdev->dev)) { case UCODE_NEW: - return microcode_reload_late(); + return load_late_stop_cpus(); case UCODE_NFOUND: return -ENOENT; default: @@ -421,7 +441,7 @@ static ssize_t reload_store(struct devic return -EINVAL; cpus_read_lock(); - ret = ucode_load_late_locked(); + ret = load_late_locked(); cpus_read_unlock(); return ret ? : size; --- a/arch/x86/kernel/cpu/microcode/internal.h +++ b/arch/x86/kernel/cpu/microcode/internal.h @@ -16,6 +16,7 @@ enum ucode_state { UCODE_UPDATED, UCODE_NFOUND, UCODE_ERROR, + UCODE_TIMEOUT, }; struct microcode_ops {