Received: by 2002:a25:8b12:0:0:0:0:0 with SMTP id i18csp2312604ybl; Thu, 29 Aug 2019 06:38:54 -0700 (PDT) X-Google-Smtp-Source: APXvYqxIo21JyGNHns0dKV1FLDM1S7FkpKcrMMHESJnKDIxfuKZ6rMHUoSCeHDcm4Ojx6dyE5P/I X-Received: by 2002:a65:6415:: with SMTP id a21mr7961578pgv.98.1567085934560; Thu, 29 Aug 2019 06:38:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1567085934; cv=none; d=google.com; s=arc-20160816; b=kLDSFR7KRvuXVWn5o6zYAW8j3sll5kSeoHkCClmKlKUK1N8xOomeWaQBSg59/MSfYl OVsUbkEbq9fFcYg+jPxScqNTfRWWzwx4Rc+XfTkKrH9b4GSQY1XejIwsYp3sc2uQytxV TlqQxwRe7uiSV0lGq+ljRXuON2DrJvminD/BiOdFXS+ego7Qb0Z+WLgqEPmymczgktlW JV6UrfYgUlM9RBsOhcUNxxEmPhyer+AR1VVaXN22J53+BdkJJsGpajWN4KOOVExGj53Y 1jC22BQCOozgZU6jiGQ+vo7ulC2L+ljBI7zGkUaY1fFeVbxOK9w/EAokFenpTHZ7Xgca 9P7g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:date:to:from:subject:message-id; bh=iubg6Af2lh+/Z3H7DyaFWXO3XK9T0iG6qd8zYGSMYfI=; b=gqBu59OFx81WO0JbbDElVE/4WFwB1NcvyJEQ5ejjq1Oa2HCwp9a8SESI8DQUd5064u 4GagNUjW+7mI+fLx1yJ7zlO13e7RQO9DQhzOvoCoMTTzZTzq+uMQ/wLQCJu1VF0AgIf6 Vs5WZXoPjDkFQTCfTjIEUMSM1aTsnt/+bnq2f+GJQEpZv+HMF0jyg8SgEezU34az39XW dAPYFpT7/7GTTsP/dfKGw+MQ8JV81v/FDit/YU5aZhlY1Dha2PKb4CbyKS6lrtuir5pG xYUB5PNdYa0lelhLNDzcu9BzFsYHNt1G/O/QqRj8LYkxyEd6LVdp7Oi0H5jxOoAzBoDQ SgyA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id c22si1832180plo.375.2019.08.29.06.38.38; Thu, 29 Aug 2019 06:38:54 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727435AbfH2Nhm (ORCPT + 99 others); Thu, 29 Aug 2019 09:37:42 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:35770 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726985AbfH2Nhm (ORCPT ); Thu, 29 Aug 2019 09:37:42 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.92.1) (envelope-from ) id 1i3KcH-000130-QZ; Thu, 29 Aug 2019 15:37:33 +0200 Message-ID: <696734afb27182d7a1a9218dd3cfa01f47a76093.camel@sipsolutions.net> Subject: Re: [PATCH] um: Rewrite host RNG driver. From: Johannes Berg To: Alexander Neville , Richard Weinberger , Anton Ivanov , linux-um@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 29 Aug 2019 15:37:32 +0200 In-Reply-To: <20190828204609.02a7ff70@TheDarkness> References: <20190828204609.02a7ff70@TheDarkness> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-08-28 at 21:44 -0400, Alexander Neville wrote: > The old driver had a bug that would cause it to outright stop working if > the host's /dev/random were to block. Instead of trying to track down > the cause of said bug, rewriting it from scratch turned out to be a much > better option as it came with a few benefits: > > - The new driver properly registers itself as an hardware RNG. > > - The code is simpler and therefore easier to maintain. > > - It serves as a minimal example of writing a hardware RNG driver. > > I also edited the Kconfig symbol to bring it up to more modern > standards. I realize that it's still easier to use, but theoretically you could just use the virtio implementation, and use that driver with a suitable small vhost device implementation. :-) johannes