From patchwork Tue Jul 19 11:53:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 12922408 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 01F08C43334 for ; Tue, 19 Jul 2022 11:54:11 +0000 (UTC) Received: from localhost ([::1]:60128 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oDlnm-0001Me-Kq for qemu-devel@archiver.kernel.org; Tue, 19 Jul 2022 07:54:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47378) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDlmy-0000gd-LE for qemu-devel@nongnu.org; Tue, 19 Jul 2022 07:53:20 -0400 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]:55934) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDlmv-0007CG-1G for qemu-devel@nongnu.org; Tue, 19 Jul 2022 07:53:20 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8B75D61632; Tue, 19 Jul 2022 11:53:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59742C341C6; Tue, 19 Jul 2022 11:53:12 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="YKXb9BW/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1658231590; 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=h2GwklyOc9qjpGkitr89pHTy6aoWg2VQ2JJFWxG5JNo=; b=YKXb9BW/VcGY3nMlcB8/WurmAy7kQo4MLqQ2J2PNz8zCDDKAmnHHK2XvCs+gEv1a5X9eYS 03TPJFCxArIr9Bn1Lg1HFlOUdsOcJd+xQxNrpJONJJgCtfKC8SazoZp1m2K3PsWSnPMgf1 jTq7F0NDIIqsjfF6FT9RQSxFhaJci1s= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 9cacd7bd (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Tue, 19 Jul 2022 11:53:10 +0000 (UTC) From: "Jason A. Donenfeld" To: qemu-devel@nongnu.org Cc: "Jason A. Donenfeld" , "Michael S . Tsirkin" , Marcel Apfelbaum , Paolo Bonzini , Richard Henderson , Eduardo Habkost , Peter Maydell , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , Laurent Vivier Subject: [PATCH resend v3] hw/i386: pass RNG seed via setup_data entry Date: Tue, 19 Jul 2022 13:53:00 +0200 Message-Id: <20220719115300.104095-1-Jason@zx2c4.com> In-Reply-To: <20220711145432.56704-1-Jason@zx2c4.com> References: <20220711145432.56704-1-Jason@zx2c4.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2604:1380:4641:c500::1; envelope-from=SRS0=TnJG=XY=zx2c4.com=Jason@kernel.org; helo=dfw.source.kernel.org X-Spam_score_int: -67 X-Spam_score: -6.8 X-Spam_bar: ------ X-Spam_report: (-6.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Tiny machines optimized for fast boot time generally don't use EFI, which means a random seed has to be supplied some other way. For this purpose, Linux (≥5.20) supports passing a seed in the setup_data table with SETUP_RNG_SEED, specially intended for hypervisors, kexec, and specialized bootloaders. The linked commit shows the upstream kernel implementation. Link: https://git.kernel.org/tip/tip/c/68b8e9713c8 Cc: Michael S. Tsirkin Cc: Marcel Apfelbaum Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Cc: Peter Maydell Cc: Philippe Mathieu-Daudé Cc: Laurent Vivier Signed-off-by: Jason A. Donenfeld --- I'm resending this because apparently I didn't CC the right group of recipients before. hw/i386/x86.c | 19 ++++++++++++++----- include/standard-headers/asm-x86/bootparam.h | 1 + 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/hw/i386/x86.c b/hw/i386/x86.c index 6003b4b2df..0724759eec 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -26,6 +26,7 @@ #include "qemu/cutils.h" #include "qemu/units.h" #include "qemu/datadir.h" +#include "qemu/guest-random.h" #include "qapi/error.h" #include "qapi/qmp/qerror.h" #include "qapi/qapi-visit-common.h" @@ -1045,6 +1046,16 @@ void x86_load_linux(X86MachineState *x86ms, } fclose(f); + setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16); + kernel_size = setup_data_offset + sizeof(struct setup_data) + 32; + kernel = g_realloc(kernel, kernel_size); + stq_p(header + 0x250, prot_addr + setup_data_offset); + setup_data = (struct setup_data *)(kernel + setup_data_offset); + setup_data->next = 0; + setup_data->type = cpu_to_le32(SETUP_RNG_SEED); + setup_data->len = cpu_to_le32(32); + qemu_guest_getrandom_nofail(setup_data->data, 32); + /* append dtb to kernel */ if (dtb_filename) { if (protocol < 0x209) { @@ -1059,13 +1070,11 @@ void x86_load_linux(X86MachineState *x86ms, exit(1); } - setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16); - kernel_size = setup_data_offset + sizeof(struct setup_data) + dtb_size; + kernel_size += sizeof(struct setup_data) + dtb_size; kernel = g_realloc(kernel, kernel_size); - stq_p(header + 0x250, prot_addr + setup_data_offset); - - setup_data = (struct setup_data *)(kernel + setup_data_offset); + setup_data->next = prot_addr + setup_data_offset + sizeof(*setup_data) + setup_data->len; + ++setup_data; setup_data->next = 0; setup_data->type = cpu_to_le32(SETUP_DTB); setup_data->len = cpu_to_le32(dtb_size); diff --git a/include/standard-headers/asm-x86/bootparam.h b/include/standard-headers/asm-x86/bootparam.h index 072e2ed546..b2aaad10e5 100644 --- a/include/standard-headers/asm-x86/bootparam.h +++ b/include/standard-headers/asm-x86/bootparam.h @@ -10,6 +10,7 @@ #define SETUP_EFI 4 #define SETUP_APPLE_PROPERTIES 5 #define SETUP_JAILHOUSE 6 +#define SETUP_RNG_SEED 9 #define SETUP_INDIRECT (1<<31)