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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14942C3A5A1 for ; Wed, 28 Aug 2019 14:47:15 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DDF4D2077B for ; Wed, 28 Aug 2019 14:47:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDF4D2077B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37202 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2zEA-0003dY-1p for qemu-devel@archiver.kernel.org; Wed, 28 Aug 2019 10:47:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53988) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2ypr-00019F-5O for qemu-devel@nongnu.org; Wed, 28 Aug 2019 10:22:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i2ypl-0007uB-Uw for qemu-devel@nongnu.org; Wed, 28 Aug 2019 10:22:06 -0400 Received: from mail.ispras.ru ([83.149.199.45]:39944) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1i2ypl-0007t5-OH for qemu-devel@nongnu.org; Wed, 28 Aug 2019 10:22:01 -0400 Received: from rainloop.ispras.ru (mail2.ispras.ru [83.149.199.43]) by mail.ispras.ru (Postfix) with ESMTPS id 478FB54006A for ; Wed, 28 Aug 2019 17:21:58 +0300 (MSK) Mime-Version: 1.0 Date: Wed, 28 Aug 2019 14:21:58 +0000 Message-ID: <51deeefdf33168ff11234ffd96ee646d@rainloop.ispras.ru> X-Mailer: RainLoop/1.9.2.343 From: poletaev@ispras.ru To: qemu-devel@nongnu.org X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 83.149.199.45 X-Mailman-Approved-At: Wed, 28 Aug 2019 10:46:19 -0400 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.23 Subject: [Qemu-devel] Can not read SMI handler code with cpu_memory_rw_debug while in SMM X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 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" I am using OVMF2018 (https://github.com/tianocore/tianocore.github.io/wik= i/OVMF) build with smm functionality. Run qemu with "-machine smm=3Don" o= ption.=0AWhen SMI handler starts working,=C2=A0cpu_memory_rw_debug() func= tion reads from tseg_blackhole device mem and function returns ffff... in= stead of actual data.=0ASame situation when using remote gdb debugging, g= uess because=C2=A0cpu_memory_rw_debug() is in use also.=0ABut code of SMI= handler executes normally, so cpu can access actual data and not tseg_bl= ackhole.=0A=0ACan anybody explain please, what is the difference in this = context between, for example,=C2=A0x86_ldub_code() and=C2=A0=C2=A0cpu_mem= ory_rw_debug()?=0AIs such behavior=C2=A0intended? (guess no)=0AWhat is ts= eg at all? I can't find similar terminology in intel manuals.