From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [IPv6:2a0f:8001:1:32::40]) by lore.proxmox.com (Postfix) with ESMTPS id 7DDED1FF12C for ; Wed, 05 Aug 2026 11:26:58 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id DFB6921824; Wed, 05 Aug 2026 11:26:57 +0200 (CEST) Message-ID: Date: Wed, 5 Aug 2026 11:26:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC qemu-server 0/4] remote migrate: extract preconditions and add check endpoint To: Erik Fastermann , pve-devel@lists.proxmox.com References: <20260721115827.163442-1-e.fastermann@proxmox.com> <2b01d1e2-56e8-47ef-986f-99f16ea1a93f@proxmox.com> Content-Language: en-US From: Fiona Ebner In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1785921999302 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.148 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) RCVD_IN_DNSWL_LOW -0.7 Sender listed at https://www.dnswl.org/, low trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: LBEZDIZF5VRS3EFKKSWFZAHIW4MWF2UG X-Message-ID-Hash: LBEZDIZF5VRS3EFKKSWFZAHIW4MWF2UG X-MailFrom: f.ebner@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Am 31.07.26 um 3:42 PM schrieb Erik Fastermann: >> Am 21.07.26 um 1:58 PM schrieb Erik Fastermann: >>> - Running the checks over the Tunnel command instead would add a new >>>    command that older endpoints do not understand. Both here and for the >>>    API, a capability/feature endpoint could help: source and/or target >>>    query what each supports for a migration, and older versions fall >>>    back to the current checks. Is that worth introducing now? >> >> The capability negotiation can be done via a new tunnel command, see: >> https://lore.proxmox.com/pve-devel/b072f9d7- >> b0f8-41fc-8c37-7ea90798aa1b@proxmox.com/ >> >> It should be possible to issue the capabilities command to the target >> and detect if the target side understands it (look at the error message >> to see if unknown or failed for other reasons) and otherwise it's too >> old and has no capabilities at all. >> > > That direction makes sense to me. Concretely: > > - Add a capabilities tunnel command, plus a precondition tunnel command > in which the source sends the relevant config and the target runs the > checks it can answer better than the source can. > > - The existing source-side checks stay. They are still the only thing > that runs against a target without the capability, so removing them > would mean no checks at all for new -> old migrations. > > - New checks that need target-side knowledge go through the new command; > new checks that are purely source-config-derived go into the shared > helper this series adds. > > - The new tunnel commands are issued by the precondition endpoint. As well as the actual migration later. > > - That leaves the current series structurally as-is, with your feedback > applied, and the tunnel work follows on top. > > What do you think about this? Sounds good to me :)