From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 CA19ECA101D for ; Sat, 31 Aug 2024 08:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YmXqT6f83TuYJGLPM/JRU7JUOq3ZPyGm7r8pV4sNdvs=; b=VXhBfoOEzBFXNTuttPVxE9Qe1B XCSqjoLiZ3ZvqJNnNTRRywAQMrE3FeWSNTzcdn/vP2QyA/MOAgqc9bcu86Kr/xD3mZek5kjMO7quw YCOl5umQEVAEw+hobqERRieDl60CMuDR2sH9RhWRsZxmPA/9ZUMnKinNGyHB213S5sCkAxSTPVN+1 e5gphIYfC/2OGtcKcz+3jZnRZ9AaOHLmS8SLV5A6VXNzjV1OIslUyM85zcUJpgNhpUvexh/1TyB1s aWyM9To91P67JqogD1SG2712d0rwKiV9ljlFMlzPiztV3l2lInJkDjLuYZ4yNFwsIIAb1r+1yRVZS svLufEDQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1skJGT-00000008vMu-1Guv; Sat, 31 Aug 2024 08:15:21 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1skJFZ-00000008vI3-3Qyc for linux-arm-kernel@lists.infradead.org; Sat, 31 Aug 2024 08:14:27 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 03F635C1097; Sat, 31 Aug 2024 08:14:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEFA7C4CEC0; Sat, 31 Aug 2024 08:14:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725092063; bh=dC9woE6OiFq0DFYL5jgTE8HMEHaGEFxF7EU9YoSWi08=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Gz4m3+VOTfGPQsRcJ+UVGQ+eae0g6/yUULBTyB65x7lfUuD0KLipbA4oTKNlSzo6F r7odGqqocNQvce2SYMYH6wWiZSbEQ9R96Z+jT03qX6P2eI/MDv8CY7eX13kRmOP2lh zAPhjfXvj3IUzc+DIHnyDFiC0T6+KHP1st2su9fJ6gfSJCuRrgA267lEC8p70a5TTB g5hYsmMW1lbBzUlUUAcy1B7dJS5xM+i32dsutdFFKDVI6H6tzwpQT5vOa0OUYSgBWW r05ASkp1FwhEKzAzSn4zRSPisH7GzcyBtf4S+vix0l1lt2Xh1F3bCLOvThO8STw852 eSwscLlvFNuRg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1skJFV-008Rjk-Eh; Sat, 31 Aug 2024 09:14:21 +0100 Date: Sat, 31 Aug 2024 09:14:20 +0100 Message-ID: <86y14dun1f.wl-maz@kernel.org> From: Marc Zyngier To: Ard Biesheuvel Cc: Tangnianyao , Will Deacon , oliver.upton@linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, "guoyang (C)" Subject: Re: Question on get random long worse in VM than on host In-Reply-To: References: <214e37e9-7aba-1e61-f63f-85cb10c9a878@huawei.com> <86zfotuoio.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: ardb@kernel.org, tangnianyao@huawei.com, will@kernel.org, oliver.upton@linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, guoyang2@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240831_011425_944306_E5B30CDA X-CRM114-Status: GOOD ( 13.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, 31 Aug 2024 08:56:23 +0100, Ard Biesheuvel wrote: > > As for RNDR/RNDRRS vs TRNG: the former is not a raw entropy source, it > is a DRBG (or CSPRNG) which provides cryptographically secure random > numbers whose security strength is limited by the size of the seed. > TRNG does not have this limitation in principle, although non-p KVM > happily seeds it from the kernel's entropy pool, which has the same > limitation in practice. Is that something we should address? I assume that this has an impact on the quality of the provided random numbers? Thanks, M. -- Without deviation from the norm, progress is not possible.