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 B00F8C83F17 for ; Sun, 13 Jul 2025 11:28:44 +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=waqohNZIdoy78eS+j2mTU3wjMCyw8XXPGbriMgKELNU=; b=xQ3Lf3ZJgY5BoQ3WZ01dJCH1/U /6EcqwRoq+bm1fiqG9c4PUeobLFPJo4j8Y+iI8fSxqNwdFkQ3EkQVKPf2ENzLkQXWh+gMSNSfc5IL x7DN9xL4NXSkCwOMkJV73GmdXnZK2fFEixkkolB64VQcJI9VtGgQZOtCkCTsNBZQC5tYsN20mTctM sVQ0F22bR7IuKNJ6f6OPeAqSW9UNTmrO2ETx/7Tsv2QwpJDZxwd+oKmBsuZwAcKh6LS1/3gc2sz/m IUkHLx/k8GbhTBW0nVDsPMpdC5Um7w+WEJ6LKO3IqKO3/jzHI55mR0K8h4J3ly36Gk0RJwa9aTwg7 L9hjM3tA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uausp-000000006Ft-0mwI; Sun, 13 Jul 2025 11:28:39 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uauqS-000000006Cz-06e8 for linux-arm-kernel@lists.infradead.org; Sun, 13 Jul 2025 11:26:13 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 580355C2BAA; Sun, 13 Jul 2025 11:26:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8F75C4CEE3; Sun, 13 Jul 2025 11:26:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752405971; bh=c3Q8QEGiOg6VqtKooLbYt69TTUZ6bQSCAr/wJwfz/lw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QemZ5N3ij1UawecXNKJxgZVK7pgLRbRPSPE+D1jjtWX6o/7sTrYM8AaA/UP1FZ0nt d/q4KZv7KCLEgAahvbj89D3L7lQytAFlTXfaSrwJT0AlZr6bfMP9SXQjRINPXsbQWw f70hLEwThDFWKHbBo12MsMj7K0M6sgzMMeBoiDt6bJDZ3RjFVV7VoQpGEup6j6QobC 9cQVoflt7qPxyLiGI7y7UH7n3rero7ecIsvgACJOfe4xWF0fcYwOfqZpqs3om8tEQX HQY8W0OYzuA/xySO3GW20m2ruYvuPzubFTgye/UadvBjSLy/+pHZHf3SkGcP95dATa 7/dIv/E69ZMsA== Date: Sun, 13 Jul 2025 12:26:05 +0100 From: Will Deacon To: DaeRo Lee Cc: alexandru.elisei@arm.com, james.morse@arm.com, kernel-team@android.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, maz@kernel.org, oliver.upton@linux.dev, qperret@google.com, sebastianene@google.com, sudeep.holla@arm.com, suzuki.poulose@arm.com, tabba@google.com Subject: Re: [PATCH v3 08/10] KVM: arm64: Handle FFA_MEM_LEND calls from the host Message-ID: References: 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-20250713_042612_108921_A16CB39E X-CRM114-Status: GOOD ( 10.58 ) 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 Sat, Jul 12, 2025 at 10:36:24PM +0900, DaeRo Lee wrote: > > Handle FFA_MEM_LEND calls from the host by treating them identically to > > FFA_MEM_SHARE calls for the purposes of the host stage-2 page-table, but > > forwarding on the original request to EL3. > > I have a question about your patch. > Does treating FFA_MEM_LEND as identical to FFA_MEM_SHARE imply that > the host can still access the memory even after it has been lent? Only if your TZ implementation is broken and relies on the NS hypervisor for isolation. Will