From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3307431326A for ; Mon, 17 Nov 2025 19:58:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763409517; cv=none; b=KNoJUqH+EoWyyRgcZTkAQzGTyao0eg64MoCMSRkXkD40G5boZA8rSXkSh7xPj1SWY04mnn1T7RToG87wEdar5dhlgi3vt/BbVgzY9cVN51M55GYygElnXRwjmhbSXBqMW8pdU8cWStYUsc6fWnNwnrJAGuN+/M9rmbfLK05FXOs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763409517; c=relaxed/simple; bh=Sd8YoOHUisYwdH08sBQL+dbV7waIqy4Ymb1r1y5wJF4=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=uh1by+Fh0zf4Fbpk6a9fNxWP+D4Bo2iKHcFc+fVLjH6UG3+ggNvIAxYRJurfeVjJ/jpKDsgzAu8ZZ13Gj2TMgJT8FSrHTFqG/C4GX+OMzkcxL8Atkt1LbHVGJfhmElum624cALXEKhYM91iFWSZqYchRzmUCgaEqlynskpzzBvg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=J7TpOpU0; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=kkdtbRgO; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="J7TpOpU0"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="kkdtbRgO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763409515; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IZWYH9y9wW76sENobGLvC7YJFZ2AxOVAfrIMs/9gvck=; b=J7TpOpU0i3fbF/Kg+3bJYxANUz8n/wanSLIdURTgRdpVoI/la6HVR0zBApgi1hb5CogHAm 4S3BlYQhx5EV9SJDzp5UdCHtMWvtp0WqgLqUgcNuMQy+FiOYbvcLSqj9kPQ8AyFguczRZV N3f5YGB61hEVCBQ6MSFoKfVyv0HHl0w= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-297-Jeh7GqOIOlW-WwQoYxEBAg-1; Mon, 17 Nov 2025 14:58:33 -0500 X-MC-Unique: Jeh7GqOIOlW-WwQoYxEBAg-1 X-Mimecast-MFC-AGG-ID: Jeh7GqOIOlW-WwQoYxEBAg_1763409513 Received: by mail-qt1-f198.google.com with SMTP id d75a77b69052e-4e8b33c1d8eso149836241cf.2 for ; Mon, 17 Nov 2025 11:58:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1763409513; x=1764014313; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:from:to :cc:subject:date:message-id:reply-to; bh=IZWYH9y9wW76sENobGLvC7YJFZ2AxOVAfrIMs/9gvck=; b=kkdtbRgOIMxTmvC11PzlqSNWUc0EIIMpSD7xRAgyg0dR9exO7eqCutj4T6Jegblj4v 2duZRAEE9Kr/Oy6FmGs3+HZo3rycuLZhJkfXjRth/RQIFnZjZ1APSW23cTj3jUf3Dxcs W0tV2yJlWT3i4uQJjt/z7c3VqnMc3d9lEAHPpiOIDIrI4dgCCjyaOTGfxQNDQMlwnBIa LOntVmfn5Cu//VFnpvJYkaCpNUaKLk+2LCbepr1KGlNa+iOWM0HfQ9hEI08fttGRlwVz srBhBxmxGEgDDiE3Tb0BTCTOm/qrTckWJVWosudYGc4Bngi7mPuHeR5k9A7e15C8REUH w1aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763409513; x=1764014313; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=IZWYH9y9wW76sENobGLvC7YJFZ2AxOVAfrIMs/9gvck=; b=jHY2/SA2/3f91EBFAQOVCgiRycFo8G3aW1Eah1aUcSq5PnpM1xYo2DhStd5dEaXz5Z DhaqjdRWcAouNse1F/mFh06ehvlJBHlgIMlJXYqt0YR5OzTTBx+zhUFTx/8zm/Sj619Y x88oOh/+8XrA+v2PW+eXbF/fjgMlDVHIoUX9UMhGDNEnSlCsC7YpG/xrSon3yw2Oyo6O Hb/cHz0eLGFtbCWhRF+xdqOLZauw3nX9nT6Xn+r8XPcnMMjDqEGvl0Y3KMEK4Vozil+4 0n3AvMenhGljtUCF/64yibozdHVyGo14FcZioNiWgjb3/XnkdY7ClVQxLB5n9YUcVxOq Uyeg== X-Forwarded-Encrypted: i=1; AJvYcCUIpUPeu3z/h+B3Wy8h9s6HeOQlajyggy6Pm+z9d6oreTKGKqub3/8jZAiVRvOuwrpUcNLGVVJrSVicZrQ=@vger.kernel.org X-Gm-Message-State: AOJu0YwuXyA3ZbOY1vpWVm950rF3eyqvOu6ddZG9v/6rGRmJBIX7PqEu 6G6GiviXFV7Az4KLpBa1JAIhvDahSJURFYNp3RigPTYfJYGBqKhyVe8kZcd6T4KZFyH2wzTbXs5 PWRe+B49QAEI+dvr4XvWyMis6W+EHwIXSCL0TA2vzMdt4QVcF8OYrp571XkCd++f7yg== X-Gm-Gg: ASbGncvyaFsv64Q0WKRAigGZfEZdisfaxZWBTG1AvoWyyh8qAfueqIVfcyk4XNds3h0 l2AuDbmNuIqFnvRDXQRPdmncjSJI86sZs5gGaBXO8H30tHyIOz2mMQV+O+Lpep8e1IRjefHMc0p A5+5etrI0tY1E6+aXUEwOCAiVLDaRVrzBs66zuYCzC8qFpuV89ckKGQyNG3WD4frLMO+f0ktNfp PCBKw8PmqHIvzNpAGK7jAiLuhmZK2kl+CP4txpJHriXMmqb4I6mQnk/JSverHAG40eO3zM+11Xu +K4yYg+dMdLIoHYxIAnAcD2z9dBHQErLiduBqbDTRAUPgiGAEERCXU89Rl6z7e9Pw2mHgN6lmNV bW1ra8GCekloJqzYSez4z2RrLKf64QgvHTTldxBOCADyADA== X-Received: by 2002:a05:622a:58c3:b0:4ee:403:7f3e with SMTP id d75a77b69052e-4ee0403a033mr128061911cf.19.1763409512909; Mon, 17 Nov 2025 11:58:32 -0800 (PST) X-Google-Smtp-Source: AGHT+IEpuw8wZd5hHeW6JbYH9CHTTK8j64vtpROS/1eUnoiD/mQULiS05nb+rLs2dfpp0whqpgnoqA== X-Received: by 2002:a05:622a:58c3:b0:4ee:403:7f3e with SMTP id d75a77b69052e-4ee0403a033mr128061591cf.19.1763409512492; Mon, 17 Nov 2025 11:58:32 -0800 (PST) Received: from ?IPV6:2601:188:c102:b180:1f8b:71d0:77b1:1f6e? ([2601:188:c102:b180:1f8b:71d0:77b1:1f6e]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4ee02763778sm59079841cf.32.2025.11.17.11.58.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Nov 2025 11:58:31 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: Date: Mon, 17 Nov 2025 14:58:30 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH tip] x86/microcode/AMD: Read from MSR_AMD64_PATCH_LEVEL to get base_rev if not defined To: Borislav Petkov Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org References: <20251117191527.1487774-1-longman@redhat.com> <20251117193750.GAaRt5jpu9XSHEawSM@fat_crate.local> Content-Language: en-US In-Reply-To: <20251117193750.GAaRt5jpu9XSHEawSM@fat_crate.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 11/17/25 2:37 PM, Borislav Petkov wrote: > On Mon, Nov 17, 2025 at 02:15:27PM -0500, Waiman Long wrote: >> AMD microcode is being handled inconsistenly depending on whether the >> CONFIG_MICROCODE_DBG is on or off. > Did you read the help text to CONFIG_MICROCODE_DBG? > I am fine if "microcode,base_rev=" is specified in the boot command line to force a base_rev for testing purpose. But if that is not specified, get_patch_level() should return the right value. The problem I have on that particular test machine mentioned in the commit is that the kernel is trying to load an incompatible microcode blob causing error like the following when CONFIG_MICROCODE_DBG is on. [    0.000000] unchecked MSR access error: WRMSR to 0xc0010020 (tried to write 0xff11000026d3e740) at rIP: 0xffffffffa72cc63b (__apply_microcode_amd+0x3b/0xb0) [    0.000000] Call Trace: [    0.000000]  [    0.000000]  ? show_trace_log_lvl+0x1b0/0x2f0 [    0.000000]  ? show_trace_log_lvl+0x1b0/0x2f0 [    0.000000]  ? ex_handler_msr.isra.0.cold+0x5b/0x60 [    0.000000]  ? fixup_exception+0x8f/0x380 [    0.000000]  ? early_fixup_exception+0x45/0xb0 [    0.000000]  ? early_idt_handler_common+0x2f/0x3a [    0.000000]  ? __apply_microcode_amd+0x3b/0xb0 [    0.000000]  ? load_ucode_amd_bsp+0x10b/0x140 [    0.000000]  ? x86_64_start_kernel+0x84/0xa0 [    0.000000]  ? common_startup_64+0x13e/0x141 [    0.000000]  [    0.000000] microcode: updated rev: 0xa101148 I can add a boot_cpu_has(X86_FEATURE_HYPERVISOR) check and use native_rdmsr() only if there is no hypervisor running. Do you think that is acceptable? Regards, Longman