From patchwork Thu Nov 7 12:21:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Cooper X-Patchwork-Id: 13866331 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 50076D43359 for ; Thu, 7 Nov 2024 12:21:40 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.831766.1247143 (Exim 4.92) (envelope-from ) id 1t91Vv-0003jv-My; Thu, 07 Nov 2024 12:21:27 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 831766.1247143; Thu, 07 Nov 2024 12:21:27 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1t91Vv-0003jo-JX; Thu, 07 Nov 2024 12:21:27 +0000 Received: by outflank-mailman (input) for mailman id 831766; Thu, 07 Nov 2024 12:21:26 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1t91Vu-0003Uc-8N for xen-devel@lists.xenproject.org; Thu, 07 Nov 2024 12:21:26 +0000 Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [2a00:1450:4864:20::62e]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id cdc17699-9d02-11ef-a0c6-8be0dac302b0; Thu, 07 Nov 2024 13:21:24 +0100 (CET) Received: by mail-ej1-x62e.google.com with SMTP id a640c23a62f3a-a9ee097a478so39568066b.2 for ; Thu, 07 Nov 2024 04:21:24 -0800 (PST) Received: from andrewcoop.eng.citrite.net ([185.25.67.249]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5cf03b5c91esm727688a12.4.2024.11.07.04.21.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Nov 2024 04:21:22 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: cdc17699-9d02-11ef-a0c6-8be0dac302b0 X-Custom-Connection: eyJyZW1vdGVpcCI6IjJhMDA6MTQ1MDo0ODY0OjIwOjo2MmUiLCJoZWxvIjoibWFpbC1lajEteDYyZS5nb29nbGUuY29tIn0= X-Custom-Transaction: eyJpZCI6ImNkYzE3Njk5LTlkMDItMTFlZi1hMGM2LThiZTBkYWMzMDJiMCIsInRzIjoxNzMwOTgyMDg0LjA4NzUzOSwic2VuZGVyIjoiYW5kcmV3LmNvb3BlckBjbG91ZC5jb20iLCJyZWNpcGllbnQiOiJ4ZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcifQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1730982083; x=1731586883; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=dhkaHQoFIRa55JOrJcaTnvyo182cpXRAkClX9uwWjpI=; b=sO82k5t5Q6dEIqdNrAUES0PJxkdj5oCkKdoq+GZElFsTYIjdjyXjW+6ONieJ12Qcuh gFc7xGMRhhRh7dzqKC+z4wsj94V7xUlY/8hOkSfMhXMlBCq2Q/ygWST+1LRS5YXR1Qmh c1MmweaBw8GZRH94LOhcHkjy9PMFSlX8Bx9Rs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730982083; x=1731586883; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=dhkaHQoFIRa55JOrJcaTnvyo182cpXRAkClX9uwWjpI=; b=pm4GiG+qeObyx5U0QNQ28ePF8BlR6D03pCta05ItCreKSikHPzejjzcPY+iQ2gZb2l F/SQ5aZPRb0u5KYLAUGJrPEtvHnx7fwZjaTFul/m9QDbDsWlcxmxlYVX5dAzrM4Edp2m PrvOiErm+Hh27Y/P/TZBtj527cGTXIbG+lq4nXVlsQU6HrD/DETwdWITLQ1wUC2szVZh 5KA4lfjpRrKuN+40a0Y+hi+O3ptWnkhnMS8S2VmHO63bZYMcLLNa9j+mZUaHqvuPgS/q RnpfQIpzvK+iIsDQaltI9ip6AAhfP7SMa0sFCkBLY+LqGRBK7jqbkbCzCJz8zYSCyM7V bTxQ== X-Gm-Message-State: AOJu0YxkCgBkyc3lXBb/5UjXE/D06Yr/SII6nY9nZsz+gQmWAIDVtAdm p49xaukRrSlTsm3DZR2PHiWDH9xKy49YJYqt8zHKsPNTZBjSCtVkgTkznhHQ8gkXC5nQ4XtpDqZ l X-Google-Smtp-Source: AGHT+IFYCiJbEL/d67ECmyal5RqaBxk7eAqjmISW2oKfrekMRSrrUF/GI3CDJgtpBs1SzNPvU+rF9Q== X-Received: by 2002:a05:6402:d05:b0:5c9:5745:de9a with SMTP id 4fb4d7f45d1cf-5ceb926152emr19520279a12.9.1730982082892; Thu, 07 Nov 2024 04:21:22 -0800 (PST) From: Andrew Cooper To: Xen-devel Cc: Andrew Cooper , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Subject: [PATCH 3/3] x86/ucode: Remove the collect_cpu_info() call from parse_blob() Date: Thu, 7 Nov 2024 12:21:17 +0000 Message-Id: <20241107122117.4073266-4-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20241107122117.4073266-1-andrew.cooper3@citrix.com> References: <20241107122117.4073266-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 With the tangle of logic starting to come under control, it is now plain to see that parse_blob()'s side effect of re-gathering the signature/revision is pointless. The cpu_request_microcode() hooks need the signature only. The BSP gathers this in early_microcode_init(), the APs and S3 in microcode_update_cpu(). For good measure, the apply_microcode() hooks also keep the revision correct as load attempts are made. This finally gets us down to a single call per CPU on boot / S3 resume, and no calls during late-load hypercalls. No functional change. Signed-off-by: Andrew Cooper --- CC: Jan Beulich CC: Roger Pau Monné Slightly RFC. Just before posting, I've realised that cpu_request_microcode() does actually use the current CPU revision, and it's buggy, and it's the cause of `xen-ucode --force` not working as expected. I'm tempted to do another series cleaning that up in isolation, such that this patch becomes true in this form. --- xen/arch/x86/cpu/microcode/core.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index fd4b08b45388..5897ec54032a 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -189,8 +189,6 @@ static struct patch_with_flags nmi_patch = */ static struct microcode_patch *parse_blob(const char *buf, size_t len) { - alternative_vcall(ucode_ops.collect_cpu_info); - return alternative_call(ucode_ops.cpu_request_microcode, buf, len, true); }