From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 255081DB92A for ; Tue, 1 Apr 2025 12:55:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743512153; cv=none; b=R33PdLDTi7NGgkYd+Fq+9L0NFwLEWZaLIfU+9KvqqWO9gw7YoioiW2Lo5NY/nJsOHw0FCj5GvtNHPnlBD9AgxVSGcyWv9V2/wm9ObM4FOs2RLKfk2AKVbmZQP5X9NHuLjbng7BRBdgv1V0hpK2YfMwdpnBxlC/4gbpjGYz50H4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743512153; c=relaxed/simple; bh=uqyToMqi0crBXol5MsKWo/VFUHfdKEBnUBxBzM5yeYk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dmyb5c8n2LNFTbpmfLDCmEEKAh4pPCgkMcH4bHZq3ePKltV4RkCO4zLhLHQKdRtcJ7bzSRHlVKU3K/P/qro4ST46cHmpv5elqEIyTL3wTc5IJYHqUGsx12cpibVddPlyOJHhj9iHjSzBgcd6hiND3ryzsAbjbgOJeuYT0H7lAVQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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