From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92D7C3BED71; Mon, 6 Jul 2026 06:05:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783317931; cv=none; b=cTS5IQcep1is+QikDUHWf81I7aMjTosVBhxhk3Eu+ICy8LPF5YaOD817ryPt/Ai+t1F58j+HInl9fmLnKKbhO80lvhg8/jxcmWfTDyPjy43WwhVi2DNObeRjStpgVAAvZdCv52ObreDGFd4zjOnFlVg9siFasXbX3aCYy7vGEYI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783317931; c=relaxed/simple; bh=msuVWLCHNHW1vdQC7on4XrTXAPjCt498LXK1+AvqECA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PANA0OKAWWo4ZOM9LGPNZxH6O4qDgrsEzU2Hba+tjM74v6mUO86BQ5dqOSSgoT/yMY9kHya0vPmNfSOLGG60c6tGh8GjGFCiAsASQCq4ulS9qzgLNw/AigGGACiaumZeM7TzS6czXW+p0sYEE1FW+tEJbbF9wJaFY6VqsM8Oc2M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mLdnhD1k; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mLdnhD1k" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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