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 X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69B6AC433E6 for ; Mon, 22 Feb 2021 11:58:42 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 9D4AE64E2E for ; Mon, 22 Feb 2021 11:58:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D4AE64E2E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=posteo.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 354BE4B17E; Mon, 22 Feb 2021 06:58:41 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@posteo.net Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hnFirJ7Vy-ls; Mon, 22 Feb 2021 06:58:39 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 320844B18B; Mon, 22 Feb 2021 06:58:34 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CCF5F4B12B for ; Mon, 22 Feb 2021 04:35:34 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8HVPc8tBjF53 for ; Mon, 22 Feb 2021 04:35:32 -0500 (EST) Received: from mout01.posteo.de (mout01.posteo.de [185.67.36.65]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 8532D4B115 for ; Mon, 22 Feb 2021 04:35:32 -0500 (EST) Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id D0E0A16005C for ; Mon, 22 Feb 2021 10:35:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1613986530; bh=VPHrBPyLWdSROwekyI2lxigDlO6mhV3Y1pk0vkdayCs=; h=Date:From:To:Cc:Subject:From; b=qrD0gdkeKCP5FiQbuP5EF4YpxR2sONuHqXB2z2ddKvno1JgWf1VK6LRZ3OHIMPh3a rx7Wuq1Me/AOI1GLIgywjXsjM/rK01Rs/qp772S4+xPc/fgv80mg+j8oJKdhXygqxP likGuez7xHrrPGWshef54ywO7PfVFNkCJ2oy+r8QT514Nzgr7CCTwfkERbbxZrbhCS WY348x0gnOMuwooJ27rrxghsv4n+gDVAF4YyeqhxdrOE+8qVfZnmKunbiGEo0w2UMd WT39ntn0RwwUQ6U0Fp+1kEqOfonrnPN9o6VGo9JWriA+Tt7fIWA5k8GA4SdntTAW1r JDDr/Cm5LKtpw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4DkcVP5xZcz6tml; Mon, 22 Feb 2021 10:35:25 +0100 (CET) Date: Mon, 22 Feb 2021 10:35:25 +0100 From: Jonathan =?utf-8?Q?Neusch=C3=A4fer?= To: Marc Zyngier Subject: Re: [PATCH v7 23/23] [DO NOT MERGE] arm64: Cope with CPUs stuck in VHE mode Message-ID: References: <20210208095732.3267263-1-maz@kernel.org> <20210208095732.3267263-24-maz@kernel.org> MIME-Version: 1.0 In-Reply-To: <20210208095732.3267263-24-maz@kernel.org> X-Mailman-Approved-At: Mon, 22 Feb 2021 06:58:33 -0500 Cc: Srinivas Ramana , Catalin Marinas , Hector Martin , linux-kernel@vger.kernel.org, Ard Biesheuvel , Will Deacon , Ajay Patil , Prasad Sodagudi , kernel-team@android.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============8384262059381688296==" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu --===============8384262059381688296== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="b/B7fiZwBVN17PG/" Content-Disposition: inline --b/B7fiZwBVN17PG/ Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Feb 08, 2021 at 09:57:32AM +0000, Marc Zyngier wrote: > It seems that the CPU known as Apple M1 has the terrible habit > of being stuck with HCR_EL2.E2H=3D=3D1, in violation of the architecture. Minor nitpick from the sideline: The M1 SoC has two kinds of CPU in it (Icestorm and Firestorm), which makes "CPU known as Apple M1" a bit imprecise. In practicality it seems unlikely though, that Icestorm and Firestorm act differently with regards to the code in this patch. Best regards, Jonathan Neusch=C3=A4fer >=20 > Try and work around this deplorable state of affairs by detecting > the stuck bit early and short-circuit the nVHE dance. It is still > unknown whether there are many more such nuggets to be found... >=20 > Reported-by: Hector Martin > Signed-off-by: Marc Zyngier > --- > arch/arm64/kernel/head.S | 33 ++++++++++++++++++++++++++++++--- > arch/arm64/kernel/hyp-stub.S | 28 ++++++++++++++++++++++++---- > 2 files changed, 54 insertions(+), 7 deletions(-) [...] --b/B7fiZwBVN17PG/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEvHAHGBBjQPVy+qvDCDBEmo7zX9sFAmAzet0ACgkQCDBEmo7z X9vfWRAAgmO7sXidDBGjzOX7cP0Tb4rOOlQY06r6tQhTtim1xJkOSpzsGJTepdaD 9hZXErHxdvCEZY/QrxZW0VpZ1W4IEDXZBvGXcfvxL7JPvbbt+mZ4QD9zZa4ue8ZJ 9LKcRSFfjsKh0+Llu+PFyqe09XqAjtRDEv0QWsyC7HYRNHmVy2lMop8IiMLcVrM3 8t3UUsflQpMQr4nFRBqgvOxK5ydrDSP8R1v6HBOVEp3FH4X/FOPO8Mbo/zcXHSMX LOvj0dCmQt9Rnm7wPkp1xbVTTD7MngQO5Df1DRm1o1lx9mxGQcIDerAoI1GRRNiA WHXO3EqxEaZAkMa08bAZzBMGARpVk9YukqQOAwiWVzpH5/YRuSGDqufzV5e2Z37J 00e1wX501ZgcduRiO+MlDD88PBPAF8ok8zm3ZwvXSs5FQr88kLGGmmiGlIe2VMNF MYt0P3j6g/Fnv7bXd8PlXohjIPVd5w0pIUm/AYqBVTmgSchP3he1CfJzQy5ICQlh +svzK/vxqI19FibpUjZ3t8qsiLmlyHoeA1KwQwbueMbxs76QqDMA0ZuvVN6Xt3ot BBAP/EcFvrFw55KxIMEPhxYsPT/OoG78RFhq0hVe7ht/8q0UF6gcFvUFla0T39oK JmKkQSqicoo79PtzMMcKUigpmrkt3NgSgNy4o+70oYnFRVpm2g4= =mdQE -----END PGP SIGNATURE----- --b/B7fiZwBVN17PG/-- --===============8384262059381688296== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm --===============8384262059381688296==--