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 06075C00140 for ; Thu, 18 Aug 2022 09:57:15 +0000 (UTC) Received: from localhost ([::1]:59760 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oOcH4-00022C-4n for qemu-devel@archiver.kernel.org; Thu, 18 Aug 2022 05:57:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60480) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oOc6M-0006wl-LL for qemu-devel@nongnu.org; Thu, 18 Aug 2022 05:46:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:34266) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oOc6F-0007kk-RH for qemu-devel@nongnu.org; Thu, 18 Aug 2022 05:46:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660815962; 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=KaqLU9Q/d4Yl08LPCBXzQuwyh1m6oGuec9Qs39Mjsbo=; b=Qbxu/kC0PNg+pa5tvlLh8L4E0uMfi0c7mfmfwG7d9spVkArJU3K5TJ2tzU3T9BSjUH7Ot5 0qMyxwh5VHVvm4G1tQjyAAqQLcw/tClIAQt55vP69q2IVgtSjMa37zmFlEFtJhFWXps5f5 7wHvbmqv7CoHW64OWSITb8eF8z7c0A8= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-516-46iUxCcAMaekBIHKbgdpYQ-1; Thu, 18 Aug 2022 05:46:01 -0400 X-MC-Unique: 46iUxCcAMaekBIHKbgdpYQ-1 Received: by mail-wm1-f69.google.com with SMTP id 203-20020a1c02d4000000b003a5f5bce876so2445102wmc.2 for ; Thu, 18 Aug 2022 02:46:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=KaqLU9Q/d4Yl08LPCBXzQuwyh1m6oGuec9Qs39Mjsbo=; b=KnNJwvHsywY2Iip4p/zU0InzsqJYh5s3MDHJDNfTMO5HKJcvFAXAqitZaEyCIy+GDE SRqqkZX5MhQETW4MiQ9OMbLdusELT0YnelZITvWv59DaLul5mKj/mnQux96exiM7KDTT 83JGBW0dBvsQ2XSjxEeQt/MIgUxlXQTLzIVra/ZB4ycA7a6wLgMPr7UFa6n4mciadgXg rlZAQdPu1vOMUXuHrLB4IH4HngAuKhHii46inkzoj76+uIGHApsJoSUfGRI1JEv9jXeU 13HdJ+eSo9UXNhaHmT7Nn4ypWd/7XvHhrxH2N1Dql8hRXXHmGXQa7PyyDvtv3fHpAZGX fDOw== X-Gm-Message-State: ACgBeo2e5CwsHLicRi1NBvttS+3w4wr1Xyh72ZaNdA4cFmoA0SXP8lm1 Hw4kBxfLT/qBQG3UR/Ts+8SKTzlVSFGWWTpAyJtljDqLJ16VvxqnUr6qv05OiJAeLrgaybmVgpP uezPx60h27WK5wFU= X-Received: by 2002:a5d:4ecb:0:b0:225:25f7:191f with SMTP id s11-20020a5d4ecb000000b0022525f7191fmr1086544wrv.205.1660815960338; Thu, 18 Aug 2022 02:46:00 -0700 (PDT) X-Google-Smtp-Source: AA6agR4EquykejJcMtonzW5iuRlNMgOlsPMA3lErdWHg88+2FXGatiRW2Bvbpvi28Y6UfAKMzwzqFg== X-Received: by 2002:a5d:4ecb:0:b0:225:25f7:191f with SMTP id s11-20020a5d4ecb000000b0022525f7191fmr1086525wrv.205.1660815959995; Thu, 18 Aug 2022 02:45:59 -0700 (PDT) Received: from work-vm (cpc109025-salf6-2-0-cust480.10-2.cable.virginm.net. [82.30.61.225]) by smtp.gmail.com with ESMTPSA id r17-20020a05600c425100b003a5bd9448e5sm1454487wmm.28.2022.08.18.02.45.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Aug 2022 02:45:59 -0700 (PDT) Date: Thu, 18 Aug 2022 10:45:57 +0100 From: "Dr. David Alan Gilbert" To: Daniel Henrique Barboza Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, clg@kaod.org, alistair.francis@wdc.com, david@gibson.dropbear.id.au Subject: Re: [PATCH for-7.2 v3 15/20] qmp/hmp, device_tree.c: introduce 'info fdt' command Message-ID: References: <20220816173428.157304-1-danielhb413@gmail.com> <20220816173428.157304-16-danielhb413@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220816173428.157304-16-danielhb413@gmail.com> User-Agent: Mutt/2.2.6 (2022-06-05) Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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" * Daniel Henrique Barboza (danielhb413@gmail.com) wrote: > Reading the FDT requires that the user saves the fdt_blob and then use > 'dtc' to read the contents. Saving the file and using 'dtc' is a strong > use case when we need to compare two FDTs, but it's a lot of steps if > you want to do quick check on a certain node or property. > > 'info fdt' retrieves FDT nodes (and properties, later on) and print it > to the user. This can be used to check the FDT on running machines > without having to save the blob and use 'dtc'. > > The implementation is based on the premise that the machine thas a FDT > created using libfdt and pointed by 'machine->fdt'. As long as this > pre-requisite is met the machine should be able to support it. > > For now we're going to add the required QMP/HMP boilerplate and the > capability of printing the name of the properties of a given node. Next > patches will extend 'info fdt' to be able to print nodes recursively, > and then individual properties. > > This command will always be executed in-band (i.e. holding BQL), > avoiding potential race conditions with machines that might change the > FDT during runtime (e.g. PowerPC 'pseries' machine). > > 'info fdt' is not something that we expect to be used aside from debugging, > so we're implementing it in QMP as 'x-query-fdt'. > > This is an example of 'info fdt' fetching the '/chosen' node of the > pSeries machine: > > (qemu) info fdt /chosen > chosen { > ibm,architecture-vec-5; > rng-seed; > ibm,arch-vec-5-platform-support; > linux,pci-probe-only; > stdout-path; > linux,stdout-path; > qemu,graphic-depth; > qemu,graphic-height; > qemu,graphic-width; > } > > And the same node for the aarch64 'virt' machine: > > (qemu) info fdt /chosen > chosen { > stdout-path; > rng-seed; > kaslr-seed; > } > > Cc: Dr. David Alan Gilbert > Signed-off-by: Daniel Henrique Barboza For HMP: Acked-by: Dr. David Alan Gilbert > --- > hmp-commands-info.hx | 13 ++++++++++ > include/monitor/hmp.h | 1 + > include/sysemu/device_tree.h | 4 +++ > monitor/hmp-cmds.c | 13 ++++++++++ > monitor/qmp-cmds.c | 12 +++++++++ > qapi/machine.json | 19 +++++++++++++++ > softmmu/device_tree.c | 47 ++++++++++++++++++++++++++++++++++++ > 7 files changed, 109 insertions(+) > > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx > index 188d9ece3b..743b48865d 100644 > --- a/hmp-commands-info.hx > +++ b/hmp-commands-info.hx > @@ -921,3 +921,16 @@ SRST > ``stats`` > Show runtime-collected statistics > ERST > + > + { > + .name = "fdt", > + .args_type = "nodepath:s", > + .params = "nodepath", > + .help = "show firmware device tree node given its path", > + .cmd = hmp_info_fdt, > + }, > + > +SRST > + ``info fdt`` > + Show a firmware device tree node given its path. Requires libfdt. > +ERST > diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h > index d7f324da59..c0883dd1e3 100644 > --- a/include/monitor/hmp.h > +++ b/include/monitor/hmp.h > @@ -135,6 +135,7 @@ void hmp_set_vcpu_dirty_limit(Monitor *mon, const QDict *qdict); > void hmp_cancel_vcpu_dirty_limit(Monitor *mon, const QDict *qdict); > void hmp_info_vcpu_dirty_limit(Monitor *mon, const QDict *qdict); > void hmp_dumpdtb(Monitor *mon, const QDict *qdict); > +void hmp_info_fdt(Monitor *mon, const QDict *qdict); > void hmp_human_readable_text_helper(Monitor *mon, > HumanReadableText *(*qmp_handler)(Error **)); > void hmp_info_stats(Monitor *mon, const QDict *qdict); > diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h > index bf7684e4ed..057d13e397 100644 > --- a/include/sysemu/device_tree.h > +++ b/include/sysemu/device_tree.h > @@ -14,6 +14,8 @@ > #ifndef DEVICE_TREE_H > #define DEVICE_TREE_H > > +#include "qapi/qapi-types-common.h" > + > void *create_device_tree(int *sizep); > void *load_device_tree(const char *filename_path, int *sizep); > #ifdef CONFIG_LINUX > @@ -137,6 +139,8 @@ int qemu_fdt_add_path(void *fdt, const char *path); > > void qemu_fdt_dumpdtb(void *fdt, int size); > void qemu_fdt_qmp_dumpdtb(const char *filename, Error **errp); > +HumanReadableText *qemu_fdt_qmp_query_fdt(const char *nodepath, > + Error **errp); > > /** > * qemu_fdt_setprop_sized_cells_from_array: > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c > index d23ec85f9d..accde90380 100644 > --- a/monitor/hmp-cmds.c > +++ b/monitor/hmp-cmds.c > @@ -2484,3 +2484,16 @@ void hmp_dumpdtb(Monitor *mon, const QDict *qdict) > error_report_err(local_err); > } > } > + > +void hmp_info_fdt(Monitor *mon, const QDict *qdict) > +{ > + const char *nodepath = qdict_get_str(qdict, "nodepath"); > + Error *err = NULL; > + g_autoptr(HumanReadableText) info = qmp_x_query_fdt(nodepath, &err); > + > + if (hmp_handle_error(mon, err)) { > + return; > + } > + > + monitor_printf(mon, "%s", info->human_readable_text); > +} > diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c > index 8415aca08c..db2c6aa7da 100644 > --- a/monitor/qmp-cmds.c > +++ b/monitor/qmp-cmds.c > @@ -603,9 +603,21 @@ void qmp_dumpdtb(const char *filename, Error **errp) > { > return qemu_fdt_qmp_dumpdtb(filename, errp); > } > + > +HumanReadableText *qmp_x_query_fdt(const char *nodepath, Error **errp) > +{ > + return qemu_fdt_qmp_query_fdt(nodepath, errp); > +} > #else > void qmp_dumpdtb(const char *filename, Error **errp) > { > error_setg(errp, "dumpdtb requires libfdt"); > } > + > +HumanReadableText *qmp_x_query_fdt(const char *nodepath, Error **errp) > +{ > + error_setg(errp, "this command requires libfdt"); > + > + return NULL; > +} > #endif > diff --git a/qapi/machine.json b/qapi/machine.json > index aeb013f3dd..96cff541ca 100644 > --- a/qapi/machine.json > +++ b/qapi/machine.json > @@ -1681,3 +1681,22 @@ > ## > { 'command': 'dumpdtb', > 'data': { 'filename': 'str' } } > + > +## > +# @x-query-fdt: > +# > +# Query for FDT element (node or property). Requires 'libfdt'. > +# > +# @nodepath: the path of the FDT node to be retrieved > +# > +# Features: > +# @unstable: This command is meant for debugging. > +# > +# Returns: FDT node > +# > +# Since: 7.2 > +## > +{ 'command': 'x-query-fdt', > + 'data': { 'nodepath': 'str' }, > + 'returns': 'HumanReadableText', > + 'features': [ 'unstable' ] } > diff --git a/softmmu/device_tree.c b/softmmu/device_tree.c > index cd487ddd4d..3fb07b537f 100644 > --- a/softmmu/device_tree.c > +++ b/softmmu/device_tree.c > @@ -18,6 +18,7 @@ > #endif > > #include "qapi/error.h" > +#include "qapi/type-helpers.h" > #include "qemu/error-report.h" > #include "qemu/option.h" > #include "qemu/bswap.h" > @@ -661,3 +662,49 @@ void qemu_fdt_qmp_dumpdtb(const char *filename, Error **errp) > > error_setg(errp, "Error when saving machine FDT to file %s", filename); > } > + > +static void fdt_format_node(GString *buf, int node, int depth) > +{ > + const struct fdt_property *prop = NULL; > + const char *propname = NULL; > + void *fdt = current_machine->fdt; > + int padding = depth * 4; > + int property = 0; > + int prop_size; > + > + g_string_append_printf(buf, "%*s%s {\n", padding, "", > + fdt_get_name(fdt, node, NULL)); > + > + padding += 4; > + > + fdt_for_each_property_offset(property, fdt, node) { > + prop = fdt_get_property_by_offset(fdt, property, &prop_size); > + propname = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); > + > + g_string_append_printf(buf, "%*s%s;\n", padding, "", propname); > + } > + > + padding -= 4; > + g_string_append_printf(buf, "%*s}\n", padding, ""); > +} > + > +HumanReadableText *qemu_fdt_qmp_query_fdt(const char *nodepath, Error **errp) > +{ > + g_autoptr(GString) buf = g_string_new(""); > + int node; > + > + if (!current_machine->fdt) { > + error_setg(errp, "Unable to find the machine FDT"); > + return NULL; > + } > + > + node = fdt_path_offset(current_machine->fdt, nodepath); > + if (node < 0) { > + error_setg(errp, "node '%s' not found in FDT", nodepath); > + return NULL; > + } > + > + fdt_format_node(buf, node, 0); > + > + return human_readable_text_from_str(buf); > +} > -- > 2.37.2 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK