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 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 A2C2DCAC5BB for ; Wed, 8 Oct 2025 06:33:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v6NjK-0003Ka-BU; Wed, 08 Oct 2025 02:32:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v6NjJ-0003KP-8D for qemu-devel@nongnu.org; Wed, 08 Oct 2025 02:32:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v6NjG-00043k-OT for qemu-devel@nongnu.org; Wed, 08 Oct 2025 02:32:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1759905168; 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: in-reply-to:in-reply-to:references:references; bh=bnXhYHxiYf28m/vX97R0O4Dj/PyL1DkrfnBkN+mEfZw=; b=bSGpamuSZQkxaJylyvJgHRJxDY94gJeT9mRp3ITp+UT6uLUK129RYuCFp1izAZR+lm0TbA fS1KcG061P5D0CjkLJATLhpEIlaa0PybB1GFSo388vlsAeqQmLno70RiP88lmhpKuOQ9ul wJXmYgumUi+Fj3bV8kV3iPc+ADXB6/c= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-135-kfqQl5o1NQqxmSVqFGnXsQ-1; Wed, 08 Oct 2025 02:32:45 -0400 X-MC-Unique: kfqQl5o1NQqxmSVqFGnXsQ-1 X-Mimecast-MFC-AGG-ID: kfqQl5o1NQqxmSVqFGnXsQ_1759905163 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DEEC7180034A; Wed, 8 Oct 2025 06:32:42 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.6]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CEA3F1800576; Wed, 8 Oct 2025 06:32:41 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5BFAD21E6A27; Wed, 08 Oct 2025 08:32:39 +0200 (CEST) From: Markus Armbruster To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Laurent Vivier , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud?= =?utf-8?Q?=C3=A9?= , Yanan Wang , Paolo Bonzini , "Dr. David Alan Gilbert" , Fabiano Rosas , Eric Blake , Eduardo Habkost , Zhao Liu Subject: Re: [PATCH v2] hw/uefi: add "info ovmf-log" + "query-ovmf-log" monitor commands In-Reply-To: <20251007135216.1687648-1-kraxel@redhat.com> (Gerd Hoffmann's message of "Tue, 7 Oct 2025 15:52:16 +0200") References: <20251007135216.1687648-1-kraxel@redhat.com> Date: Wed, 08 Oct 2025 08:32:39 +0200 Message-ID: <87347toqd4.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.422, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org Gerd Hoffmann writes: > Starting with the edk2-stable202508 tag OVMF (and ArmVirt too) have > optional support for logging to a memory buffer. There is guest side > support -- for example in linux kernels v6.17+ -- to read that buffer. > But that might not helpful if your guest stops booting early enough that > guest tooling can not be used yet. So host side support to read that > log buffer is a useful thing to have. > > This patch implements both qmp and hmp monitor commands to read the > firmware log. > > Signed-off-by: Gerd Hoffmann [...] > diff --git a/tests/qtest/qmp-cmd-test.c b/tests/qtest/qmp-cmd-test.c > index cf718761861d..ffdb7e979e0f 100644 > --- a/tests/qtest/qmp-cmd-test.c > +++ b/tests/qtest/qmp-cmd-test.c > @@ -52,6 +52,8 @@ static int query_error_class(const char *cmd) > /* Only valid with accel=tcg */ > { "x-query-jit", ERROR_CLASS_GENERIC_ERROR }, > { "xen-event-list", ERROR_CLASS_GENERIC_ERROR }, > + /* requires firmware with memory buffer logging support */ > + { "query-ovmf-log", ERROR_CLASS_GENERIC_ERROR }, > { NULL, -1 } > }; > int i; Makes sense. > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx > index 6142f60e7b16..eca0614903d1 100644 > --- a/hmp-commands-info.hx > +++ b/hmp-commands-info.hx > @@ -977,3 +977,16 @@ SRST > ``info cryptodev`` > Show the crypto devices. > ERST > + > + { > + .name = "ovmf-log", > + .args_type = "", > + .params = "", > + .help = "show the ovmf debug log", > + .cmd_info_hrt = qmp_query_ovmf_log, > + }, > + > +SRST > + ``info ovmf-log`` > + Show the ovmf debug log. > +ERST > diff --git a/hw/uefi/meson.build b/hw/uefi/meson.build > index 91eb95f89e6d..c8f38dfae247 100644 > --- a/hw/uefi/meson.build > +++ b/hw/uefi/meson.build > @@ -1,4 +1,4 @@ > -system_ss.add(files('hardware-info.c')) > +system_ss.add(files('hardware-info.c', 'ovmf-log.c')) > > uefi_vars_ss = ss.source_set() > if (config_all_devices.has_key('CONFIG_UEFI_VARS')) > diff --git a/qapi/machine.json b/qapi/machine.json > index 038eab281c78..329034035029 100644 > --- a/qapi/machine.json > +++ b/qapi/machine.json > @@ -1839,6 +1839,16 @@ > 'returns': 'HumanReadableText', > 'features': [ 'unstable' ]} > > +## > +# @query-ovmf-log: > +# > +# Find firmware memory log buffer in guest memory, return content. > +# > +# Since: 10.2 > +## > +{ 'command': 'query-ovmf-log', > + 'returns': 'HumanReadableText' } All other commands returning HumanReadableText are unstable. Does this one need to be stable? If yes, why? > + > ## > # @dump-skeys: > #