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 7AEFCC36014 for ; Tue, 1 Apr 2025 13:02:36 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=U3u5KPB8g1UKvvqA8vB6epeTkayE9kNOIoRw4sBjIkk=; b=1G2SD/3g99JC9yQ7O4K/3ws4qc slQiUzTgbTdmp/PFxRhTTTME18kuAuo94jMK0eMrA2cVzmIrbaYMYrG5qkM93mtjEn951GfeJFHi1 dY+73lL29JT7I3ii+Veis8JNxwKJfxPmY3Tjrx6kgz8yZZKD09ppyf52+X9kXQDFtNV7mTsTK/cKI qrFy3VBzffYbuxHV6Lan+Qmq18gOc9aXIFihp54W266imRWvEqVl9TPKTcMIVLacacw2d/a/rIEaG KUJo7HAvjh57AhhYBmE3fXQ6zCvUmZQRKKpEJhNts6oEngRku06G7xmmVwyt4Bb+ZG4RiWQKj3NN3 URPNNkuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzbG4-00000003NkK-3kCV; Tue, 01 Apr 2025 13:02:24 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzb9l-00000003Mbj-3ldZ for linux-arm-kernel@lists.infradead.org; Tue, 01 Apr 2025 12:55:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B52AD150C; Tue, 1 Apr 2025 05:55:54 -0700 (PDT) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 409373F694; Tue, 1 Apr 2025 05:55:48 -0700 (PDT) Date: Tue, 1 Apr 2025 13:55:45 +0100 From: Sudeep Holla To: Quentin Perret Cc: Sebastian Ene , catalin.marinas@arm.com, joey.gouly@arm.com, maz@kernel.org, oliver.upton@linux.dev, Sudeep Holla , snehalreddy@google.com, suzuki.poulose@arm.com, vdonnefort@google.com, will@kernel.org, yuzenghui@huawei.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com, Andrei Homescu Subject: Re: [PATCH v4 3/3] KVM: arm64: Release the ownership of the hyp rx buffer to Trustzone Message-ID: <20250401-innocent-outrageous-deer-0946c5@sudeepholla> References: <20250326113901.3308804-1-sebastianene@google.com> <20250326113901.3308804-4-sebastianene@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250401_055553_986036_65AD8F35 X-CRM114-Status: GOOD ( 18.50 ) 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 Tue, Apr 01, 2025 at 12:00:38PM +0000, Quentin Perret wrote: > On Friday 28 Mar 2025 at 14:18:55 (+0000), Sebastian Ene wrote: > > > > If we apply what I suggested earlier we won't have an issue with the > > semantic for this call but it would make the code a mess. I don't think > > for this particular call keeping semantics really makes a difference. > > Right, if we implemented the release call properly in pKVM I'd be happy > with this patch, but I just don't think we should only do one half. We > either do it properly in pKVM or leave it with to the host -- the latter > feels simpler to me, but no strong opinions. > FYI: As part of the earlier discussion with respect to clarification on this from the FF-A spec, I found even the driver was not handling this correctly. I have posted the fix since and plan to get it merged as fix for v6.15 -- Regards, Sudeep [1] https://lore.kernel.org/r/20250321115700.3525197-1-sudeep.holla@arm.com