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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 3B64FC282EC for ; Tue, 11 Mar 2025 09:43:40 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.907585.1314792 (Exim 4.92) (envelope-from ) id 1trw8s-0004vX-KH; Tue, 11 Mar 2025 09:43:18 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 907585.1314792; Tue, 11 Mar 2025 09:43:18 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1trw8s-0004vQ-Hf; Tue, 11 Mar 2025 09:43:18 +0000 Received: by outflank-mailman (input) for mailman id 907585; Tue, 11 Mar 2025 09:43:17 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1trw8r-0004vI-TA for xen-devel@lists.xenproject.org; Tue, 11 Mar 2025 09:43:17 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.96) (envelope-from ) id 1trw8r-00EU7v-1m; Tue, 11 Mar 2025 09:43:17 +0000 Received: from [2a02:8012:3a1:0:d5e1:ab8b:3d02:5aa4] by xenbits.xenproject.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1trw8r-003fno-0Q; Tue, 11 Mar 2025 09:43:17 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID; bh=uRkFwsIkJpRqp/tGMVml8fG0APWEeRFzwwMeHmBqz6o=; b=w4L9EvK3kHrW9UIOucx7NKNyH5 rQrk6qZ/ksuVTIm05FeXqhiaKwiVyB6MDxwOvK1gBTtVNSM5kn92bXLBpZygcnywQvii/CYdWJyM3 lrVctdjTcowCSSM/Yu5xZu5Jq0x3QP0VlO0iR25cbhc1sR7BrVwWXrEXxLMIG9FJGHCU=; Message-ID: <526952a6-eb7a-4055-bd3f-eae1af203f80@xen.org> Date: Tue, 11 Mar 2025 09:43:14 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 7/9] docs: update xenstore migration stream definition Content-Language: en-GB To: Juergen Gross , xen-devel@lists.xenproject.org Cc: Andrew Cooper , Anthony PERARD , Michal Orzel , Jan Beulich , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Stefano Stabellini References: <20250204113407.16839-1-jgross@suse.com> <20250204113407.16839-8-jgross@suse.com> From: Julien Grall In-Reply-To: <20250204113407.16839-8-jgross@suse.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Juergen, On 04/02/2025 11:34, Juergen Gross wrote: > In order to close a race window for Xenstore live update when using > the new unique_id of domains, the migration stream needs to contain > this unique_id for each domain known by Xenstore. > > Signed-off-by: Juergen Gross > --- > V8: > - new patch > --- > docs/designs/xenstore-migration.md | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/docs/designs/xenstore-migration.md b/docs/designs/xenstore-migration.md > index 082314bf72..fba691ee0d 100644 > --- a/docs/designs/xenstore-migration.md > +++ b/docs/designs/xenstore-migration.md > @@ -156,7 +156,7 @@ the domain being migrated. > ``` > 0 1 2 3 4 5 6 7 octet > +-------+-------+-------+-------+-------+-------+-------+-------+ > -| conn-id | conn-type | | > +| conn-id | conn-type | uniq-id-off | > +-------------------------------+---------------+---------------+ > | conn-spec> ... > @@ -165,6 +165,9 @@ the domain being migrated. > +---------------+---------------+-------------------------------+ > | data > ... > ++---------------------------------------------------------------+ > +| unique-id | > ++---------------------------------------------------------------+ > ``` > > > @@ -178,6 +181,12 @@ the domain being migrated. > | | 0x0001: socket | > | | 0x0002 - 0xFFFF: reserved for future use | > | | | > +| `uniq-id-off` | The offset (in octets) of the `unique-id` | > +| | field from the start of the record body. | > +| | If 0, no `unique-id` field is present. | > +| | Only needed for `shared ring` connection in | > +| | live update streams. | > +| | | Looking at the rest of the record, the unique ID would be past the in-data (length is 2-byte) and the out-data (length is 4-byte). So technically the offset would need 5-bytes. But here you are using 2-bytes. Can you explain why? Cheers, -- Julien Grall