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 5B006C3ABC0 for ; Thu, 8 May 2025 05:21:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uCtgH-00045v-5p; Thu, 08 May 2025 01:20:25 -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 1uCtgG-00045K-1G for qemu-devel@nongnu.org; Thu, 08 May 2025 01:20:24 -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 1uCtgE-00025U-Gi for qemu-devel@nongnu.org; Thu, 08 May 2025 01:20:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1746681621; 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=jr3NJCU53AwGoYjfRqX+83IhR18S1oPkNFu225Q4L4c=; b=eoOdGZ8o41vvBfKC4fIrGLk4T9D+lWVgunAIHowDm0UNKjZv+PJ9iKBw7gKd3MaW7oR0JH kQYvqLNHI7v4tJyDohfS5ZjWytivzRkceBeKrtoN9WwwBh06EvRVXVF/XrS+gBfIHGBJ4e 8CROy5IH9UyFjXj2szFIKR/RznMwAdU= Received: from mx-prod-mc-06.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-591-UttzWJRsPV-OAlRc_spRkA-1; Thu, 08 May 2025 01:20:17 -0400 X-MC-Unique: UttzWJRsPV-OAlRc_spRkA-1 X-Mimecast-MFC-AGG-ID: UttzWJRsPV-OAlRc_spRkA_1746681616 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3D7C1180034A; Thu, 8 May 2025 05:20:16 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.27]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BDC0D180049D; Thu, 8 May 2025 05:20:15 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 07CD421E66C3; Thu, 08 May 2025 07:20:13 +0200 (CEST) From: Markus Armbruster To: Nir Soffer Cc: qemu-devel@nongnu.org, Eric Blake , qemu-block@nongnu.org, Kevin Wolf , Fam Zheng , Hanna Reitz Subject: Re: [PATCH v2 1/2] block/null: Report DATA if not reading zeroes In-Reply-To: <87wmarelsh.fsf@pond.sub.org> (Markus Armbruster's message of "Thu, 08 May 2025 07:03:42 +0200") References: <20250430203717.16359-1-nirsof@gmail.com> <20250430203717.16359-2-nirsof@gmail.com> <87plgjg1kh.fsf@pond.sub.org> <87wmarelsh.fsf@pond.sub.org> Date: Thu, 08 May 2025 07:20:13 +0200 Message-ID: <87ikmbel0y.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 10.30.177.93 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: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.414, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=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: 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 Markus Armbruster writes: > Markus Armbruster writes: > >> Nir Soffer writes: [...] >>> diff --git a/qapi/block-core.json b/qapi/block-core.json >>> index b1937780e1..7c95c9e36a 100644 >>> --- a/qapi/block-core.json >>> +++ b/qapi/block-core.json >>> @@ -3293,8 +3293,9 @@ ## # @BlockdevOptionsNull: # # Driver specific block device options for the null backend. # # @size: size of the device in bytes. Missing: default value. # # @latency-ns: emulated latency (in nanoseconds) in processing >>> # requests. Default to zero which completes requests immediately. >>> # (Since 2.4) >>> # >>> -# @read-zeroes: if true, reads from the device produce zeroes; if >>> -# false, the buffer is left unchanged. >>> +# @read-zeroes: if true, emulate a sparse image, and reads from the >>> +# device produce zeroes; if false, emulate an allocated image but >>> +# reads from the device leave the buffer unchanged. >>> # (default: false; since: 4.1) >>> # >>> # Since: 2.9 >> >> Possibly dumb question: how is this doc change related to the code fix? >> >> Suggest to split the sentence for easier reading: >> >> # @read-zeroes: If true, emulate a sparse image, and reads from the >> # device produce zeroes. If false, emulate an allocated image, >> # but reads from the device leave the buffer unchanged. > > false is a security hazard, as secure-coding-practices.rst points out. > I think it should be pointed out right here as well. Especially since > "security hazard" is the default! > > I'd do it in a separate patch, but I'm a compulsive patch splitter.