From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 1C682155A59 for ; Mon, 29 Jan 2024 16:37:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706546272; cv=none; b=sypqyFWfkO7NTuEAq/d1vyPGxE7b7dmixXGnO3zNJRy6k/x0BZLH74ZVwQqOUxlEhivqT4Ewkxt5rEz0zRZTCjw3d8ludZoik/XnPTp9bblgqlq9191k37r0Kt5CJM9KRZZgf33sr7uJKnqB+nn4UpDmRcyEQwBKcQlfaTZQVWI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706546272; c=relaxed/simple; bh=Vv0bghzWikF0hRqV3J+Zqtj67Ynj9bVIOzXQeSr1MR0=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=qBEnFDjZht8ia0xTxbhqA2yNAhIZuuvHOzX3pm2Cqh+/0ffCWSnyC/HjDBvpNg1ccfhpsjR1KnNANy+P3FdNTKym6cLycDi8lUIen02QWHWoFio4nBp/cv55FB8IpSPTDWznsSpD+mBRhKE0nGz9ArCcsVIXkvoyY46xYi8Q6jc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=fail (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=lnbTimrl reason="signature verification failed"; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="lnbTimrl" Received: from [127.0.0.1] ([76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 40TGbI5I2234742 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Mon, 29 Jan 2024 08:37:18 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 40TGbI5I2234742 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024011201; t=1706546240; bh=jnhiHc2vJcf7shopPtxezoFGdpgQ4x3ykCkhtXB1nVg=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=lnbTimrlMHWAIptNbJLJlsWk/ZzejlJYo7i0NhbqKX9pzTjQwc1sC18gGk04/K1Vx ZQoNUJVCAsPQDcfuiVOMC+hHMvmcHNR4gV30x3Reh/GArk3M0GuqP9J7HFMXw8ROrW WDJIE4tPLzANlznjDrUZzesM7aG8dCKOk0avC3eQJesc3AZesr8FOoh+aWpeuRcF1R 1uwPPJQbs0aMUuaROMcO1xBvlD4dWvMjvHjWxiUQFBzRZem/0i5tZSs2ZZbjC2jfzw ksMDFTp1rRWnnYhS0c3AA3Q408uLhT9kulckKPMW65ZJZefIQtXt37V/3hxCR9c/fw pHH7xjAennTcw== Date: Mon, 29 Jan 2024 08:37:15 -0800 From: "H. Peter Anvin" To: Dave Hansen , "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Theodore Ts'o" , "Jason A. Donenfeld" CC: Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [RFC] Randomness on confidential computing platforms User-Agent: K-9 Mail for Android In-Reply-To: <276aaeee-cb01-47d3-a3bf-f8fa2e59016c@intel.com> References: <20240126134230.1166943-1-kirill.shutemov@linux.intel.com> <276aaeee-cb01-47d3-a3bf-f8fa2e59016c@intel.com> Message-ID: <82842879-FD34-4652-9714-AEE1F237EFF4@zytor.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On January 29, 2024 8:30:11 AM PST, Dave Hansen = wrote: >On 1/26/24 05:42, Kirill A=2E Shutemov wrote: >> 3=2E Panic after enough re-tries of RDRAND/RDSEED instructions fail=2E >> Another DoS variant against the Guest=2E > >I think Sean was going down the same path, but I really dislike the idea >of having TDX-specific (or CoCo-specific) policy here=2E > >How about we WARN_ON() RDRAND/RDSEED going bonkers? The paranoid folks >can turn on panic_on_warn, if they haven't already=2E That would be good anyway=2E