From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5C11678B5C for ; Tue, 30 Jan 2024 18:35:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706639754; cv=none; b=oX+acHiFuCtuN7MzzB1UcI223HAREYcpkuh/cIKyAwh8n8bPVk7yc1PxFPatUz6GTOpPtxxqptIIosyC3qVdQJbvDWXZso/KM0AeF3P/JF5sRn+BZqm+JBGFCAGUeANGHH5cwLXmM8POKH97I5FSxowRffpf9vPkCzquK9z+lys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706639754; c=relaxed/simple; bh=NuMYWAxwqeNbqERKu7z/ZwgR5K09xc1UznlMLRamtZo=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=hNMCCxnZq8b4HwJHh35gUSgovXM0Gks7BNR2LrIsUmF6y+LPtlUhbWwOLpLFJLH5QL8ivh8pUUvD9bNVHZwj12mDPPzhMS2kAcnfr/Ggr9j78bIXy5aws02lUX9r7SnBlWL4o7Smk37kXhxWhUEDC8HjV4k+5prSgBeFJJBpP2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=BakQh+UC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="BakQh+UC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B44FAC43394 for ; Tue, 30 Jan 2024 18:35:53 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="BakQh+UC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1706639749; 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=NuMYWAxwqeNbqERKu7z/ZwgR5K09xc1UznlMLRamtZo=; b=BakQh+UCfaj1zpm4b5gUspdyrLDHcS/dcFK8tGb6OSAu/ygcaX9PR1brtswGOOu0IBd8MI mycaWwEMdBZaHrg53Rc1orNFGGfhFCZ16TwAICdym9Bmk1N75O92OBXC3AyCvjs35h4IM/ s8C3UFxOwhPA9BaX0ILVzCWmMb0o8u0= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 97d42684 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Tue, 30 Jan 2024 18:35:48 +0000 (UTC) Received: by mail-yw1-f174.google.com with SMTP id 00721157ae682-5ffcb478512so860067b3.0 for ; Tue, 30 Jan 2024 10:35:48 -0800 (PST) X-Gm-Message-State: AOJu0YxiXmpbOWIpb7xcUy4x6szPbeuBpr2HL4aJ+PVTokLssRos2Ahr I65j/x5e+VBXScUDsqwnNg5VfhUFpLoAlUGCgPUcg4vOPLvnNoA7SOVTziECK6qPmqsN3+Jexxk LWcz/GPrxXuHT53zdAM+hvFimPms= X-Google-Smtp-Source: AGHT+IHMdn33Y7X7wOCyIM6bq/75Q3LozeaSggSqml0kxX+dPbbqD2gOU75ezhMfyw3lAYvr0JMTiKonEZ20IXLI3lE= X-Received: by 2002:a81:84cc:0:b0:5ff:9390:26d9 with SMTP id u195-20020a8184cc000000b005ff939026d9mr1435511ywf.20.1706639747037; Tue, 30 Jan 2024 10:35:47 -0800 (PST) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240130083007.1876787-1-kirill.shutemov@linux.intel.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Tue, 30 Jan 2024 19:35:36 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/2] x86/random: Retry on RDSEED failure To: "Reshetova, Elena" Cc: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "x86@kernel.org" , "Theodore Ts'o" , Kuppuswamy Sathyanarayanan , "Nakajima, Jun" , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "linux-coco@lists.linux.dev" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Elena, On Tue, Jan 30, 2024 at 3:06=E2=80=AFPM Jason A. Donenfeld wrote: > 2) Can a malicious host *actually* create a fully deterministic > environment? One that'll produce the same timing for the jitter > entropy creation, and all the other timers and interrupts and things? > I imagine the attestation part of CoCo means these VMs need to run on > real Intel silicon and so it can't be single stepped in TCG or > something, right? So is this problem actually a real one? And to what > degree? Any good experimental research on this? I'd like to re-up this question. It seems like assessing the reality of the concern would be worthwhile. Jason