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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AEE4C677F1 for ; Tue, 17 Jan 2023 20:39:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229490AbjAQUiT (ORCPT ); Tue, 17 Jan 2023 15:38:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235248AbjAQUfv (ORCPT ); Tue, 17 Jan 2023 15:35:51 -0500 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE28233451 for ; Tue, 17 Jan 2023 11:21:00 -0800 (PST) Received: by mail-io1-xd2b.google.com with SMTP id q130so2397647iod.4 for ; Tue, 17 Jan 2023 11:21:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:from:user-agent:mime-version:date:message-id:from:to :cc:subject:date:message-id:reply-to; bh=fqyWeWuyc2jRA+5UQYAEtNEii+X4xnVBaHeZrCTvJ0E=; b=WOZiCO0nwdx0/J8RBZ6fUPgASslwTEHjMpdR/SRXtTppO1orXLf+wGpPFAGLkaYr1x OXLmo4L7yLAGA/t16oMCARlsfHU9udsdYYFEWSEPfBAu2jAAhX/3BmhFlbT03H3ElQ3f z2YeV4v8PshtbvM8VhbsyOBdNp/0iFw2tBVfXD0fS955lXZ6AhUOb/t8S3KjJWmIcAyz dWAdwJQro88EBSHB+tSQQqs6DWMWmYU7UFfyEC/EA4d7GdhjRYyjryeAfKTjoJZb+igk JIvT4TOCREnVJp7LIXkVZP/mU8LOw0s/VbrPvNgHeayr12eYVspqEVx5/+zbgbNXXPhq PVGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:from:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=fqyWeWuyc2jRA+5UQYAEtNEii+X4xnVBaHeZrCTvJ0E=; b=Fzcf3WQxQdRStDKa/WsHFUtnOPGcVLxj4jyNK4KaCjaWSHA7tvFBg617CRu6dh/7Is mTeylglGOSLgNMVXqO0zjvdbxcOxI2/0tjeeWX6H5EoiotZaxaxi2WtIK2t7MwR7BQWN 9gLeGZ0Mltuf6jvjZyi0+yxQ2m0BVjcq5GAode2t9X6+nEKoGE8QwFj/hAJMaQEwuxBC K5EF6yv2q0a7CBkV8CZFlAmQpHdk7PXrvHHzxgDf6+kqxB28cWa3g8V9pZZONUu6Jcc3 dKUYgH5g9W/l7BVnOH0aeOK1xCo9bLApmOXhX7vFwVJ/6cx5Dtc7gp1iqdliLHlVqGV3 z2OA== X-Gm-Message-State: AFqh2koboYuw4mpfuEXJZIgPRlSdNNWoVDBxb1untX+sBrnHFgEceunq xoLRH5c9H7+ULea2UuyVhnM2CA== X-Google-Smtp-Source: AMrXdXuk5GmCedTTwYstxz043kwWiO1txPjdUTef03V7SzkRyplINEz+OO3rRduwblja8AQXWLIq1w== X-Received: by 2002:a6b:14c2:0:b0:6eb:68a1:78c with SMTP id 185-20020a6b14c2000000b006eb68a1078cmr3273688iou.10.1673983260051; Tue, 17 Jan 2023 11:21:00 -0800 (PST) Received: from [172.22.22.4] ([98.61.227.136]) by smtp.googlemail.com with ESMTPSA id e10-20020a026d4a000000b0038ac4923addsm9518035jaf.53.2023.01.17.11.20.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 17 Jan 2023 11:20:59 -0800 (PST) Message-ID: Date: Tue, 17 Jan 2023 13:20:58 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 From: Alex Elder Subject: Re: [PATCH v8 05/28] virt: gunyah: Add hypercalls to identify Gunyah To: Elliot Berman , Alex Elder , Bjorn Andersson , Catalin Marinas , Will Deacon , Murali Nalajala Cc: Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Prakruthi Deepak Heragu , Arnd Bergmann , Greg Kroah-Hartman , Rob Herring , Krzysztof Kozlowski , Jonathan Corbet , Bagas Sanjaya , Jassi Brar , Sudeep Holla , Mark Rutland , Lorenzo Pieralisi , Dmitry Baryshkov , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org References: <20221219225850.2397345-1-quic_eberman@quicinc.com> <20221219225850.2397345-6-quic_eberman@quicinc.com> <63bbc640-9b0c-95af-3d35-291da0323db3@linaro.org> <4e8a7fdf-8c91-cf2f-d369-c67b7584f580@quicinc.com> Content-Language: en-US In-Reply-To: <4e8a7fdf-8c91-cf2f-d369-c67b7584f580@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 1/10/23 11:56 AM, Elliot Berman wrote: >>> There are two calls to help identify Gunyah: >>> >>> 1. gh_hypercall_get_uid() returns a UID when running under a Gunyah >>>     hypervisor. >>> 2. gh_hypercall_hyp_identify() returns build information and a set of >>>     feature flags that are supported by Gunyah. >> >> The first is a "service", while the second is a "hypercall". >> Can you explain the distinction?  The sentence at the top >> refers to both as "hypercalls". >> > > I learned more details about this to answer your question. "get_uid()" > is a standardized call that is ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID > defined in include/arm-smccc.h. I'll use that. You didn't really explain the distinction between hypercall and service in Gunyah. Both are encoded as "vendor specific hypervisor service calls" according to the SVCCC specification. I haven't found where ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID gets handled, but I accept your answer that it's basically a standard call. The "get UID" is the only one that's defined as a Gunyah "service"; the rest are hypercalls. It's not a big deal, I just noticed the difference and was curious about it. -Alex