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 30294C43458 for ; Mon, 6 Jul 2026 06:05:39 +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:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2mDRZjsUoooCKSx6+cGErtBppIOM6woSiVm/h9NK9rw=; b=oxkC4X3RqQNpLzVHLThfCThn6g kZVgGG6vI5RALzHuIHOLQGTQr/eV61LJW/Lab13SSuub8DDTdKAqcuZqBR+o13/LP6JVSDXa2EiXk fg0thHP/h63j4CH3H/n0QJEvJGtMvJubc6jlqE7XbDDzTeifLhF0uLPGK8DXxc47KYEn6jZaS0ahm xuLIw2PRbvbMTp1aeejVkpvc9G1zKGqKjo5zrzVGD0Z4WTww+qlPfLvKixZHOskUXcBpAtk1BcgRf +pvDlLudpptGAuMnFhcS+VV8E1RIRO0ClTk2rIM7BPZqnAc3KmjDPSs/Mi8ty0rmF19xfXTMpHABQ OVxxZugA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgcSS-0000000BZLI-0uvg; Mon, 06 Jul 2026 06:05:32 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgcSR-0000000BZKk-07Pc for linux-arm-kernel@lists.infradead.org; Mon, 06 Jul 2026 06:05:31 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 7922F60018; Mon, 6 Jul 2026 06:05:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14D011F000E9; Mon, 6 Jul 2026 06:05:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783317930; bh=2mDRZjsUoooCKSx6+cGErtBppIOM6woSiVm/h9NK9rw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mLdnhD1kG8xgRaq7xeKn+0Jdkzs3dhgyB9D6ZWISaKFEAjULs9ky4Wg1vFAJPeu5Q NG67xdOLMrKAaRb6VOAcys684HHW3a01occrLAafreV+9XqK9iXtg9aoZhuKOLkWkd StTEZtqTz3zGzUFEJnAUgOoG5Ff2scGN5lvUf5zpWNq9OIYYT1wxRKm8cyNrQZjlrn Pi9XVtWAqSSSkhlwyJvd9lnHHRgNP/cAG3ORvmkbghTTPek3BPQ1qqmWCiOHiHiW/Z vZ7gGgp8NkG3rOHWHjPVgKzL+l6slZez3B/WhGSJbztUaKWDwTe1pHNg8U9HOIu3R9 YrIQoaI6WI/6w== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Catalin Marinas , Jason Gunthorpe , Marc Zyngier , Marek Szyprowski , Robin Murphy , Steven Price , Suzuki K Poulose , Thomas Gleixner , Will Deacon Subject: [PATCH v5 06/10] swiotlb: Reject misaligned restricted DMA pools for CoCo guests Date: Mon, 6 Jul 2026 11:34:28 +0530 Message-ID: <20260706060432.1375570-7-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260706060432.1375570-1-aneesh.kumar@kernel.org> References: <20260706060432.1375570-1-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Restricted DMA pools are described by firmware reserved-memory nodes and are not resized or realigned by the kernel. For confidential-computing guests, such pools can only be shared safely when both the base address and size are aligned to the shared-granule size. Reject restricted DMA pools that are not aligned to mem_cc_shared_granule_size() when guest memory encryption is active. Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/swiotlb.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1d77746b6f31..ad8a1ccf3977 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -2002,6 +2002,20 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, * if platform supports memory encryption, * restricted mem pool is shared by default */ + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) { + size_t cc_shared_granule_size = mem_cc_shared_granule_size(); + + if (!IS_ALIGNED(rmem->base, cc_shared_granule_size) || + !IS_ALIGNED(rmem->size, cc_shared_granule_size)) { + dev_err(dev, "Restricted DMA pool must be aligned to %#zx bytes for memory encryption\n", + cc_shared_granule_size); + kfree(pool->areas); + kfree(pool->slots); + kfree(mem); + return -EINVAL; + } + } + if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) { int ret; -- 2.43.0