From patchwork Fri May 10 10:26:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 1097951 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 450mc218WNz9sD4 for ; Fri, 10 May 2019 20:27:13 +1000 (AEST) Received: from localhost ([127.0.0.1]:40734 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP2kB-0007Tm-EN for incoming@patchwork.ozlabs.org; Fri, 10 May 2019 06:27:11 -0400 Received: from eggs.gnu.org ([209.51.188.92]:56692) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP2jk-0007Tg-JH for qemu-devel@nongnu.org; Fri, 10 May 2019 06:26:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hP2ji-0000Mg-L1 for qemu-devel@nongnu.org; Fri, 10 May 2019 06:26:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36898) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hP2ji-0000K5-Dq for qemu-devel@nongnu.org; Fri, 10 May 2019 06:26:42 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B5B32A4D21; Fri, 10 May 2019 10:26:40 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.40.205.9]) by smtp.corp.redhat.com (Postfix) with ESMTP id 61E1C5D70D; Fri, 10 May 2019 10:26:38 +0000 (UTC) From: Laurent Vivier To: qemu-devel@nongnu.org Date: Fri, 10 May 2019 12:26:37 +0200 Message-Id: <20190510102637.10209-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 10 May 2019 10:26:40 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2] rng-builtin: add an RNG backend that uses qemu_guest_getrandom() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , =?utf-8?q?Daniel_P_=2E_Berrang?= =?utf-8?b?w6k=?= , Kashyap Chamarthy , Amit Shah , Richard Henderson , Markus Armbruster , "Richard W . M . Jones" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add a new RNG backend using QEMU builtin getrandom function. It can be created and used with something like: ... -object rng-builtin,id=rng0 -device virtio-rng,rng=rng0 ... Reviewed-by: Richard Henderson Signed-off-by: Laurent Vivier Reviewed-by: Daniel P. Berrangé --- Notes: This patch applies on top of "[PATCH v5 00/24] Add qemu_getrandom and ARMv8.5-RNG etc" Based-on: 20190510012458.22706-1-richard.henderson@linaro.org v2: Update qemu-options.hx describe the new backend and specify virtio-rng uses the rng-random by default (do we want to change this?) backends/Makefile.objs | 2 +- backends/rng-builtin.c | 56 ++++++++++++++++++++++++++++++++++++++++++ qemu-options.hx | 10 +++++++- 3 files changed, 66 insertions(+), 2 deletions(-) create mode 100644 backends/rng-builtin.c diff --git a/backends/Makefile.objs b/backends/Makefile.objs index ff619d31b461..8da4a508d97b 100644 --- a/backends/Makefile.objs +++ b/backends/Makefile.objs @@ -1,4 +1,4 @@ -common-obj-y += rng.o rng-egd.o +common-obj-y += rng.o rng-egd.o rng-builtin.o common-obj-$(CONFIG_POSIX) += rng-random.o common-obj-$(CONFIG_TPM) += tpm.o diff --git a/backends/rng-builtin.c b/backends/rng-builtin.c new file mode 100644 index 000000000000..b1264b745407 --- /dev/null +++ b/backends/rng-builtin.c @@ -0,0 +1,56 @@ +/* + * QEMU Builtin Random Number Generator Backend + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "sysemu/rng.h" +#include "qapi/error.h" +#include "qapi/qmp/qerror.h" +#include "qemu/main-loop.h" +#include "qemu/guest-random.h" + +#define TYPE_RNG_BUILTIN "rng-builtin" +#define RNG_BUILTIN(obj) OBJECT_CHECK(RngBuiltin, (obj), TYPE_RNG_BUILTIN) + +typedef struct RngBuiltin { + RngBackend parent; +} RngBuiltin; + +static void rng_builtin_request_entropy(RngBackend *b, RngRequest *req) +{ + RngBuiltin *s = RNG_BUILTIN(b); + + while (!QSIMPLEQ_EMPTY(&s->parent.requests)) { + RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests); + + qemu_guest_getrandom_nofail(req->data, req->size); + + req->receive_entropy(req->opaque, req->data, req->size); + + rng_backend_finalize_request(&s->parent, req); + } +} + +static void rng_builtin_class_init(ObjectClass *klass, void *data) +{ + RngBackendClass *rbc = RNG_BACKEND_CLASS(klass); + + rbc->request_entropy = rng_builtin_request_entropy; +} + +static const TypeInfo rng_builtin_info = { + .name = TYPE_RNG_BUILTIN, + .parent = TYPE_RNG_BACKEND, + .instance_size = sizeof(RngBuiltin), + .class_init = rng_builtin_class_init, +}; + +static void register_types(void) +{ + type_register_static(&rng_builtin_info); +} + +type_init(register_types); diff --git a/qemu-options.hx b/qemu-options.hx index 0191ef8b1eb7..3e2a51c691b0 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4280,13 +4280,21 @@ other options. The @option{share} boolean option is @var{on} by default with memfd. +@item -object rng-builtin,id=@var{id} + +Creates a random number generator backend which obtains entropy from +QEMU builtin functions. The @option{id} parameter is a unique ID that +will be used to reference this entropy backend from the @option{virtio-rng} +device. + @item -object rng-random,id=@var{id},filename=@var{/dev/random} Creates a random number generator backend which obtains entropy from a device on the host. The @option{id} parameter is a unique ID that will be used to reference this entropy backend from the @option{virtio-rng} device. The @option{filename} parameter specifies which file to obtain -entropy from and if omitted defaults to @option{/dev/random}. +entropy from and if omitted defaults to @option{/dev/random}. By default, +the @option{virtio-rng} device uses this RNG backend. @item -object rng-egd,id=@var{id},chardev=@var{chardevid}