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 EE826C48BEB for ; Wed, 21 Feb 2024 15:46:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rcoaH-0007Ii-WC; Wed, 21 Feb 2024 10:32:34 -0500 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 1rcoSD-0003RC-4n for qemu-devel@nongnu.org; Wed, 21 Feb 2024 10:24:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rcijE-0001Ro-BS for qemu-devel@nongnu.org; Wed, 21 Feb 2024 04:17:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708507043; 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=hKemNzyEDxMR9dRSjFinPfyeeGDMuqmVo7SqJ7xLIK0=; b=fmdgtgXgseihgFDYh51jOLAzl7S4b1pcNWF8J+4/5ltIBCmg+xstIPbhN09JPiYc6/cT5P UAfsrLCVjG97tuvBWEMrvUdT3wkB9ZNYFYX78IoZM0hjXJ92yQH4eIQzt9RKnWNNZInKTc F3Dc5KT4pCi/VBTbMN2PM8xnUv2Rly4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-584-tStC8PaQO3uvM17QAyOpXw-1; Wed, 21 Feb 2024 04:17:18 -0500 X-MC-Unique: tStC8PaQO3uvM17QAyOpXw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9EB148630C6; Wed, 21 Feb 2024 09:17:18 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7C54D2022AAA; Wed, 21 Feb 2024 09:17:18 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 64CE121E6740; Wed, 21 Feb 2024 10:17:14 +0100 (CET) From: Markus Armbruster To: Fabiano Rosas Cc: qemu-devel@nongnu.org, berrange@redhat.com, Peter Xu , Claudio Fontana , Eric Blake Subject: Re: [PATCH v4 27/34] migration: Add direct-io parameter In-Reply-To: <20240220224138.24759-28-farosas@suse.de> (Fabiano Rosas's message of "Tue, 20 Feb 2024 19:41:31 -0300") References: <20240220224138.24759-1-farosas@suse.de> <20240220224138.24759-28-farosas@suse.de> Date: Wed, 21 Feb 2024 10:17:14 +0100 Message-ID: <87h6i2xjl1.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 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@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=-0.05, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 Fabiano Rosas writes: > Add the direct-io migration parameter that tells the migration code to > use O_DIRECT when opening the migration stream file whenever possible. > > This is currently only used with the fixed-ram migration that has a > clear window guaranteed to perform aligned writes. > > Signed-off-by: Fabiano Rosas [...] > diff --git a/qapi/migration.json b/qapi/migration.json > index 3fce5fe53e..41241a2178 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -878,6 +878,9 @@ > # @mode: Migration mode. See description in @MigMode. Default is 'normal'. > # (Since 8.2) > # > +# @direct-io: Open migration files with O_DIRECT when possible. This > +# requires that the 'fixed-ram' capability is enabled. (since 9.0) 'fixed-ram' is a cross-reference to MigrationCapability member fixed-ram. For local members, @name is better than 'name', because @name carries meaning, while 'name' could be anything. Currently, @name is merely shorthand for ``name``, which is an reST "inline literal", commonly used for short code snippets. Rendered in fixed-width font, unlike 'name'. Making @name generating a link to the description would be a nice improvement. For non-local members, we can't make @name a link without also specifying the thing it's a member of. Let's stick to @name for member names, even non-local ones, so we get the same font for all of them. > +# > # Features: > # > # @deprecated: Member @block-incremental is deprecated. Use > @@ -911,7 +914,8 @@ > 'block-bitmap-mapping', > { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] }, > 'vcpu-dirty-limit', > - 'mode'] } > + 'mode', > + 'direct-io'] } > > ## > # @MigrateSetParameters: > @@ -1070,6 +1074,9 @@ > # @mode: Migration mode. See description in @MigMode. Default is 'normal'. > # (Since 8.2) > # > +# @direct-io: Open migration files with O_DIRECT when possible. This > +# requires that the 'fixed-ram' capability is enabled. (since 9.0) > +# > # Features: > # > # @deprecated: Member @block-incremental is deprecated. Use > @@ -1123,7 +1130,8 @@ > '*x-vcpu-dirty-limit-period': { 'type': 'uint64', > 'features': [ 'unstable' ] }, > '*vcpu-dirty-limit': 'uint64', > - '*mode': 'MigMode'} } > + '*mode': 'MigMode', > + '*direct-io': 'bool' } } > > ## > # @migrate-set-parameters: > @@ -1298,6 +1306,9 @@ > # @mode: Migration mode. See description in @MigMode. Default is 'normal'. > # (Since 8.2) > # > +# @direct-io: Open migration files with O_DIRECT when possible. This > +# requires that the 'fixed-ram' capability is enabled. (since 9.0) > +# > # Features: > # > # @deprecated: Member @block-incremental is deprecated. Use > @@ -1348,7 +1359,8 @@ > '*x-vcpu-dirty-limit-period': { 'type': 'uint64', > 'features': [ 'unstable' ] }, > '*vcpu-dirty-limit': 'uint64', > - '*mode': 'MigMode'} } > + '*mode': 'MigMode', > + '*direct-io': 'bool' } } > > ## > # @query-migrate-parameters: Other than that, QAPI schema Acked-by: Markus Armbruster