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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 375AAC83F1A for ; Mon, 21 Jul 2025 17:49:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=F0WeBj2bGuuRDUrwwzYEPFuv3oAaANMb0rzB3x/zEGs=; b=3ng/+iwW6V8xPyffchX+rPtT5K o2vTz7To7CrskaPXq1c/UU2bHXkTc2c7dJkPb7/3smUVmIpXLXNQSKWoNNWqClf3sA1TtlKAXfCnq DxOrDmPwCCKQxPXKCLtzbTIP3CjZ9sshSWV5CwiaX+/a5p45kVsgyVkm+0OP4DxVilyCtjrbbIRJr pWiUIv2lgEGKuTOIKuH5f9NAo8pr+AWcychwccBA7NRIYcHLxAze3V82Wix+4Xb/STq+wajnuGA/C SWz2uzoYltPDYG9i0Eb8ZSfRW+Z9RJiQ8as1Sx/clur96SHJEG4laTjfFOXe67SRl3zjGGYlCgvCw Pqyll7NQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ududU-00000000Mcd-0m5S; Mon, 21 Jul 2025 17:49:12 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uduC9-00000000It1-2BEB for linux-arm-kernel@lists.infradead.org; Mon, 21 Jul 2025 17:20:58 +0000 Received: from [10.137.184.60] (unknown [131.107.160.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 82C482115836; Mon, 21 Jul 2025 10:20:54 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 82C482115836 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1753118454; bh=F0WeBj2bGuuRDUrwwzYEPFuv3oAaANMb0rzB3x/zEGs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=M6lAY38nEFF6SPpxTb0jBP9+abnYKMYir5Krk+urbD9Y4Z3t0/8JxNOMoSNX0fUsO FpNzv3YTYyKxz1aNCxTInjwirrXdr/tAAFV9m67PV5iaHZKfIqy5hqXiBd9RY4hSKN QIvH+QrTMRImtRgveFS0jbwSC3/UPzX3dY5iu3vc= Message-ID: <55e5f8d2-2b81-4883-a9ac-ad1a426c4222@linux.microsoft.com> Date: Mon, 21 Jul 2025 10:20:54 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: kvm, smccc: Fix vendor uuid To: Sudeep Holla , Jack Thomson Cc: mark.rutland@arm.com, lpieralisi@kernel.org, arnd@arndb.de, wei.liu@kernel.org, mhklinux@outlook.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, kvmarm@lists.linux.dev, roypat@amazon.com, Jack Thomson References: <20250721130558.50823-1-jackabt.amazon@gmail.com> <20250721-proficient-carrot-cockatoo-393ae1@sudeepholla> Content-Language: en-US From: Roman Kisel In-Reply-To: <20250721-proficient-carrot-cockatoo-393ae1@sudeepholla> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250721_102057_597919_B791E61E X-CRM114-Status: GOOD ( 15.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 7/21/2025 9:15 AM, Sudeep Holla wrote: > (I can't see this original patch in my mailbox, got only Marc's response) > > On Mon, Jul 21, 2025 at 02:05:58PM +0100, Jack Thomson wrote: >> From: Jack Thomson >> >> Commit 13423063c7cb ("arm64: kvm, smccc: Introduce and use API for >> getting hypervisor UUID") replaced the explicit register constants >> with the UUID_INIT macro. However, there is an endian issue, meaning >> the UUID generated and used in the handshake didn't match UUID prior to >> the commit. >> >> The change in UUID causes the SMCCC vendor handshake to fail with older >> guest kernels, meaning devices such as PTP were not available in the >> guest. >> >> This patch updates the parameters to the macro to generate a UUID which >> matches the previous value, and re-establish backwards compatibility >> with older guest kernels. >> > > Nice catch. This is result of classic confusion with UUID and GUID especially > coming from Microsoft who tend to use GUID more. > > Reviewed-by: Sudeep Holla > > This also makes me wonder if the initialisation in arch/arm64/hyperv/mshyperv.c > is also wrong or may be that's correct only MS guys can confirm as I couldn't > find the UUID string for that. MUCH appreciated!! Apologies for that miss in testing of the older kernels. I'll check on our side and will fix what needs fixing. > -- Thank you, Roman