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 54C6EC433EF for ; Thu, 24 Feb 2022 10:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0isUn2rob+9w8Q6kUpqfuq/8hA8An+r0oks9xn7sDoQ=; b=nfvuuoO8HUSVC+ gVZVqWBkpP/zROd4xBfllmylnrj/QX1dxcuDSiF5oeYf1H2fEkwLug5MHNLJTdOV67J+UFUF9CNSV c27tW+M04BgJ2EaH7wOGv8+UN++hWPLJdytudmCJEvm5giBL3eh8KM1M/hUzKS46hUQHkzSia651N 90nyHFSV2q9eYCcdBj0T6ftfqz3q4aYmdQDhQPGBIVPPbl9B2/eiAPfmE/hbHGTOTqRTKLXb6p4Fr vQaZUerfFmvA0Kyv3kjh/DXbGLjFEodfuHKEsSehuzZ33lqzjTg2YBBmPOGaQmV8R140D1h+eX9ov EGHmOC+sIOol0M5C0sbA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNBK9-000JgK-9f; Thu, 24 Feb 2022 10:26:13 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNBK4-000Jf7-Sq for linux-arm-kernel@lists.infradead.org; Thu, 24 Feb 2022 10:26:10 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 878EAB82511; Thu, 24 Feb 2022 10:26:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D17CC340E9; Thu, 24 Feb 2022 10:26:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645698365; bh=/Muanj6F0P6ufCvutPrTXUCoq7899wGHsyaNdapLJ/c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UB/f4wtXoXjeoOoprgTWU0+Q6hMuQJevM8Z3J7ySKbAtBir7Co9Cpbd6+z4CU2x6d oTXgr0yanU2PEyYMuB0kJRr8NUezbnfVe6Fz9S8iXAW9gQCPdu7cfm8+jrVWEjid5h FEoN5NIWk2LKmpOOy+vjnSrHFsdXugIUXbpNZ6TXOqJmMJ/R2llShw3tZdubbhOdJp aOXdnKiHiDbQaNo73O23C1os+p7lL1KdVwR1K8tSha5qwbZNf0QzsBlwvWUk1R8G86 7sUTloCGrnAez6efRTZknVkxRQlAfplKjta/QV1y1mTBDttnnAgxM3HB/cRx/4Cw6g i1d3jDcOwbm/Q== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nNBJy-00A9Ij-Pn; Thu, 24 Feb 2022 10:26:02 +0000 Date: Thu, 24 Feb 2022 10:26:02 +0000 Message-ID: <874k4o4l39.wl-maz@kernel.org> From: Marc Zyngier To: Elliot Berman , Mark Rutland Cc: Bjorn Andersson , linux-kernel@vger.kernel.org, Trilok Soni , Murali Nalajala , Srivatsa Vaddagiri , Carl van Schaik , Andy Gross , linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lorenzo Pieralisi , Sudeep Holla Subject: Re: [PATCH 03/11] arm64: gunyah: Add Gunyah hypercalls ABI In-Reply-To: References: <20220223233729.1571114-1-quic_eberman@quicinc.com> <20220223233729.1571114-4-quic_eberman@quicinc.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: quic_eberman@quicinc.com, mark.rutland@arm.com, bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org, quic_tsoni@quicinc.com, quic_mnalajala@quicinc.com, quic_svaddagiri@quicinc.com, quic_cvanscha@quicinc.com, agross@kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220224_022609_315152_13F526CD X-CRM114-Status: GOOD ( 28.31 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Thanks Mark for roping me in. On Thu, 24 Feb 2022 10:10:02 +0000, Mark Rutland wrote: > > Hi, > > As a general thing, this is the *only* patch from this series which has > been Cc'd to linux-arm-kernel, which makes it practically impossible to > understand the context for this, which is somewhat frustrating. > > Looking on lore.kernel.org I see that the entire series was Cc'd to > linux-arm-msm, but most people don't subscribe to that list. If you send > one patch in a series to a list, please send the *entire* series there. > > On Wed, Feb 23, 2022 at 03:37:21PM -0800, Elliot Berman wrote: > > Add initial support to perform Gunyah hypercalls. The arm64 ABI for > > Gunyah hypercalls generally follows the AAPCS64, and can be summarized: > > - Function identifier is passed through the imm operand > > - [r0,r7] are parameter and result registers > > - [r8-r18] are temporary and saved by the caller (VM) > > - [r19-r31] are preserved and saved by the hypervisor > > > > The preprocessor macors for creating the necessary HVC instruction > > roughly follows the SMCCC 1.1 implementation in > > include/linux/arm-smccc.h. > > I've added the SMCCC maintainers (myself, Lorenzo, and SUdeep) to Cc, > and also Marc who was involvedi n prior discussions in this area. Please > Cc us on any future patches adding HVC or SMCC interfaces (SMCCC or > otherwise). In general, please Cc all the interested parties with the whole series. Random patches randomly cc'd out of context are pretty useless and only lead to them being ignored. > > We've previously said NO to any new hypercall mechanisms which do not > follow SMCCC. There is no reason to fragment this space further; please > use SMCCC (which your hypervisor must already implement in part if it > exposes PSCI to a guest). > > NAK to this non-SMCCC interface. Agreed. We pushed back on that for Hyper-V, and I don't see a reason for changing tack on that. The calling convention exists for a reason: portability. If this hypervisor is to be "independent of any high-level OS kernel" (as it is being advertised), then it must already implement SMCCC. What is the issue with properly supporting SMCCC for all interactions with the hypervisor and not reinventing a square wheel? Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel