From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from atuin.qyliss.net (localhost [IPv6:::1]) by atuin.qyliss.net (Postfix) with ESMTP id 460D1C243; Sat, 01 Aug 2026 18:40:59 +0000 (UTC) Received: by atuin.qyliss.net (Postfix, from userid 993) id BF7D1C22C; Sat, 01 Aug 2026 18:40:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on atuin.qyliss.net X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,DMARC_PASS,RCVD_IN_DNSWL_LOW,RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL,SPF_HELO_PASS autolearn=unavailable autolearn_force=no version=4.0.1 Received: from mail-4399.protonmail.ch (mail-4399.protonmail.ch [185.70.43.99]) by atuin.qyliss.net (Postfix) with ESMTPS id 7A976C22B for ; Sat, 01 Aug 2026 18:40:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=colbyt.com; s=protonmail; t=1785609654; x=1785868854; bh=n4Vjv7hT2mq7VX3ZkSUCxCvYlgX3CETW6mj/HTwMUi8=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=Qg9tKlabSlk2bknUgs9gI38daOyitzSJxG8GXH3M80i6EReIHR58OVwBRxGlrC3Z8 Btri/egiYWQBXT9l6m53gveM/ywHc/vbixXDQYkQdLbT9dSSgwdsE0H9ow8tCABh4f pTxiI4U076WUDAUDERbRmU3QcQaW23evqJFxhKtvu4+BwVzXUrNj+u2z14m4B8aHGh LcCjxQSitZPo3gM/EVFeqefOjJzC3+hCdXLXzgdNqqiWsDxFT/O15HxHxgrfzZtAE3 UexpTNpQ/VdaM0VRHdpcLiCDJvqjfq3nhon8E44Kk2rFKfcktKs2OMX1aomTSvKHrY ZDERiwHJltCkw== Date: Sat, 01 Aug 2026 18:40:48 +0000 To: Alyssa Ross From: colby@colbyt.com Subject: Re: [PATCH v3] vm: optional 16K-page guest kernel builds Message-ID: In-Reply-To: <877bmb2r2e.fsf@alyssa.is> References: <20260730192035.1900845-1-colby@colbyt.com> <20260730193541.1928150-1-colby@colbyt.com> <877bmb2r2e.fsf@alyssa.is> Feedback-ID: 70977973:user:proton X-Pm-Message-ID: adfb0f8e14071352728098b74f2389f032da8e3f MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-ID-Hash: OLFZ3PLCNYD4W2URZPXFXE6HL34PJIED X-Message-ID-Hash: OLFZ3PLCNYD4W2URZPXFXE6HL34PJIED X-MailFrom: colby@colbyt.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; header-match-devel.spectrum-os.org-0; header-match-devel.spectrum-os.org-1; header-match-devel.spectrum-os.org-2; header-match-devel.spectrum-os.org-3; header-match-devel.spectrum-os.org-4; emergency; member-moderation CC: devel@spectrum-os.org X-Mailman-Version: 3.3.10 Precedence: list List-Id: Patches and low-level development discussion Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Seems fine, I don't have any special perspective on that. Everything I hav= e is 16k. On Friday, July 31st, 2026 at 7:04 AM, Alyssa Ross wrote: > colbyt writes: >=20 > > KVM hosts with a 16K stage-2 granule (Apple Silicon machines running > > upstream kernels, NVIDIA GB10) can only run guests whose kernel is buil= t > > with ARM64_16K_PAGES. Add an optional kernelPageSize argument to the ap= p > > and net VM kernel builds; the default is unchanged. A 16K-page guest > > Image built this way has booted to a full session under a 16K host here > > since June without issues on my side. > > --- > > v3/v2: no code change =E2=80=94 drop a stray in-body From line that wou= ld have > > misattributed authorship when applied. > > > > Following up on the offer in my July 7 mail, as a standalone patch now > > that the nixpkgs update brings Linux 7.1. The config delta is five > > lines; the edit (an argument defaulting to today's behavior) is a > > proposal =E2=80=94 happy to rework it if you'd rather structure it diff= erently, > > e.g. hang it off a single shared helper instead of two arguments. >=20 > My instinct is that we should just always use a 16K page kernel on > aarch64 hosts. AIUI the main reason most Linux distributions don't is > to retain compatibility with binaries that may assume only 4K alignment > is needed, but on the Spectrum host we should never be running binaries > we didn't build ourselves. >