From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.mixaill.net (mail.mixaill.net [144.76.234.135]) (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 C7AE64A01 for ; Wed, 12 Mar 2025 13:17:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=144.76.234.135 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741785480; cv=none; b=N62QYXFNgvEQWUSDchwkM8O1I7dw1DXMzwmF/SxIMlqYFl1xIiR9bQZFeuTKcl5qbeS8NWdFlulDhZv6yPJ9ToKXNzMHFA5kPPiWJFezi5i0eSaSZi4y6g6FvZytkciOkbEt92LzBbQytkyTD8bf/ADGzAucTWr3iX/PpW4fr94= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741785480; c=relaxed/simple; bh=7z/nrmh5N+ZhnoVRQxxrFg29kWXCe5+G836Gz43HkV0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UCe+EAkh6pJCzpl9OT7lpt+HFiAwpGmzQ1E+/nqgupR14RYVwQarrFvodQliHpHooIzq6P2mqbBz75dxX9L6cGoY4SslS5pF4Y2jw8oM/LbC7Ql6KbS9dkowkzxx0+fFwlFknmLbu9z0/bpigLLboYqavjiHOZixApuCkhZGDaw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mixaill.net; spf=pass smtp.mailfrom=mixaill.net; dkim=pass (2048-bit key) header.d=mixaill.net header.i=@mixaill.net header.b=Jfvn6vb0; arc=none smtp.client-ip=144.76.234.135 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mixaill.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mixaill.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mixaill.net header.i=@mixaill.net header.b="Jfvn6vb0" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 089EE618C6; Wed, 12 Mar 2025 13:17:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mixaill.net; s=dkim; t=1741785476; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:content-language:in-reply-to:references; bh=uApGfAkwTNuZ/0f/uziF7SShu01cdICgTAzmtr/PVtc=; b=Jfvn6vb0f4UmjlyAPM8y1aR6pvL0oQdMXGrzY2kTxiREmbG2e+MH8iKkqDB/h9lUqJqSj+ hv5V1mWWADGbgR347Wo0/kViPCDE3dKbieWgvY+iLN11GUFx4EHS2aL75PIovOVJtfj5DQ wt5fIFTs+N9UmyQU5WROcsYh5fuATMgz8eCGxCCAyb+8q0zadhuLJtGGTYvCTGMwfcEoxh Cgc4kC5teSdfXoy+qgUV03BsoAXrwumYUYIt9VZ7zwKR5dEBrzNgKz40gO8K8TrLLlSqCS VyH2lrNceDhEs7rxr7nUPsLnp9v6eY7JP6H/dBBikBHfZZYzfSZHZoVIk7Wb4Q== Message-ID: <10f010ca-b79f-4886-ba18-3013560905b2@mixaill.net> Date: Wed, 12 Mar 2025 16:17:52 +0300 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 0/2] x86/rdrand: implement sanity check for RDSEED To: Borislav Petkov Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, Mario Limonciello References: <20250312123130.8290-1-me@mixaill.net> <20250312124006.GCZ9GApgQQ49dO_BMW@fat_crate.local> Content-Language: en-US From: Mikhail Paulyshka In-Reply-To: <20250312124006.GCZ9GApgQQ49dO_BMW@fat_crate.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 On 3/12/25 3:40 PM, Borislav Petkov wrote: > On Wed, Mar 12, 2025 at 03:31:28PM +0300, Mikhail Paulyshka wrote: >> On the AMD Cyan Skillfish (Family 0x17 Model 0x47 Stepping 0x0), which >> is a Zen2-based APU found on the AMD BC-250 board, there is a situation >> where RDRAND works fine, but RDSEED generates FF. This leads to some >> applications that use RDSEED to generate random numbers (such as >> Qt and KDE) into a nearly unusable state. >> >> Although AMD has fixed the Zen2 RDRAND issues in 2019 with a microcode update, >> no such update has been released for the Family 0x17 Model 0x47 core. > What's the microcode level on that machine? > dmesg | grep -i microcode [ 0.059689] [ T0] Zenbleed: please update your microcode for the most optimal fix [ 0.663746] [ T1] microcode: Current revision: 0x08407007 > Also, send > > cpuid -r https://paste.debian.net/1362645