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 lists1p.gnu.org (lists1p.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 AEF98C88E64 for ; Mon, 14 Sep 2026 09:01:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x62YT-0005tt-Db; Mon, 14 Sep 2026 05:00:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x62YR-0005tW-0j for qemu-devel@nongnu.org; Mon, 14 Sep 2026 05:00:48 -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 1x62YO-0003DC-Qo for qemu-devel@nongnu.org; Mon, 14 Sep 2026 05:00:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789376444; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=C/U5kWaSWBu/lz4gb7OE4mlsf2F1rBZISq9HNZUjyLU=; b=fRcxLpROZHuBxtX3B7Xg/Fl1SOyhjO2CT1upHt3EZ+/JIsotiLVBhsoDk4Wl23GEYxxrFc gs2FWaCZfBmeA8tygSWGGCg6LkkO0we0oTXaSKXOY1JQebiOj9upm20MiqW2B04jcHHon4 gNBL1RH3+MBIrgqnGhEc1JkvQUMoCMU= 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-509-an-6r4r1MGW9x_1iGpZLsQ-1; Mon, 14 Sep 2026 05:00:41 -0400 X-MC-Unique: an-6r4r1MGW9x_1iGpZLsQ-1 X-Mimecast-MFC-AGG-ID: an-6r4r1MGW9x_1iGpZLsQ_1789376440 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 AA7FD1805A11; Mon, 14 Sep 2026 09:00:39 +0000 (UTC) Received: from thuth-p1g4.redhat.corp (headnet03.pony-001.prod.iad2.dc.redhat.com [10.2.32.114]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A5CB4195604D; Mon, 14 Sep 2026 09:00:37 +0000 (UTC) From: Thomas Huth To: Kevin Wolf , qemu-block@nongnu.org Cc: Hanna Reitz , Paolo Bonzini , qemu-devel@nongnu.org Subject: [PATCH v2] block: Print simple help text when calling "-blockdev help" Date: Mon, 14 Sep 2026 11:00:36 +0200 Message-ID: <20260914090036.125300-1-thuth@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H2=-0.01, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 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: qemu development 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 Other command line options like "-chardev", "-netdev" or "-device" already present the user with a list of available parameters, but when running "-blockdev help", there is currently only an error message. There is already the possibility to run "-drive format=help", but it does not seem to be documented, so this is not very useful for the average user. Thus let's improve this situation by providing a proper list of available drivers when running QEMU with "-blockdev help". Signed-off-by: Thomas Huth --- v2: Don't re-use the code from "-drive format=help" and print the help in a better readable way instead include/block/block-common.h | 1 + block.c | 15 +++++++++++++++ system/vl.c | 7 +++++-- 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/include/block/block-common.h b/include/block/block-common.h index 895ea175413..c76a72c1220 100644 --- a/include/block/block-common.h +++ b/include/block/block-common.h @@ -583,5 +583,6 @@ char *path_combine(const char *base_path, const char *filename); char *bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, Error **errp); +void bdrv_show_help(void); #endif /* BLOCK_COMMON_H */ diff --git a/block.c b/block.c index f0a6042e616..895d6db5acf 100644 --- a/block.c +++ b/block.c @@ -524,6 +524,21 @@ bool bdrv_uses_whitelist(void) return use_bdrv_whitelist; } +static void bdrv_help_format_print(void *opaque, const char *name) +{ + if (bdrv_format_is_whitelisted(name, false)) { + printf("%s\n", name); + } else { + printf("%s (read-only)\n", name); + } +} + +void bdrv_show_help(void) +{ + printf("Available blockdev drivers:\n"); + bdrv_iterate_format(bdrv_help_format_print, NULL, true); +} + typedef struct CreateCo { BlockDriver *drv; char *filename; diff --git a/system/vl.c b/system/vl.c index 9bd7664b85c..dc93e8737cb 100644 --- a/system/vl.c +++ b/system/vl.c @@ -2960,7 +2960,10 @@ void qemu_init(int argc, char **argv) HD_OPTS); break; case QEMU_OPTION_blockdev: - { + if (is_help_option(optarg)) { + bdrv_show_help(); + exit(EXIT_SUCCESS); + } else { Visitor *v; BlockdevOptionsQueueEntry *bdo; @@ -2973,8 +2976,8 @@ void qemu_init(int argc, char **argv) visit_free(v); loc_save(&bdo->loc); QSIMPLEQ_INSERT_TAIL(&bdo_queue, bdo, entry); - break; } + break; case QEMU_OPTION_drive: if (!qemu_opts_parse_noisily(qemu_find_opts("drive"), optarg, false)) { -- 2.55.0