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 C4722445AC6; Fri, 4 Sep 2026 10:35:36 +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=1788518138; cv=none; b=m2bGtFaJVclUoUXgBwah4pQMzxpRMc5YT0DqieCXMB8pY9fOQ5f4/MCw5sNZZrFk+4Lox5bNruH/+yLleBpVDByJHgGgbifR5lZZrOCLVicyvPCyg31efqsTgaRwcysyDehZ1j51NtTW6Kekpz86SS6mA/ecehn84mACgfNZfDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788518138; c=relaxed/simple; bh=ifGW4IhadanzTNkJq0sUWSJNoZHVkSGpNG64Glyf8lk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=clQfFzUJx6sCHK5z5vt3pHpEEZ1TRSY5GTjQQIg2rSjtLHTdWbweZkSlk0h/LelaKZ2Vr8L3XjSQSQvxzFhR8EUNr74HrJwg0/fAcQIkcKSjYP7+DdfWOZqSzhtbG0NNL6cLs69/G6ADizJV7SfE+6WRp0ow58sUGw4H4h09l+s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NtwiJQNm; 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="NtwiJQNm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F5E11F00A3D; Fri, 4 Sep 2026 10:35:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788518136; bh=zdjsjsW7gTao4JGqSdtTZcqDO/daSds2ybCp3eONEAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NtwiJQNmBfj5pcFUU1SRjet42Lr3ykAyOTfvl5s/CFq27c/0PRf0StcdZDxH3Jb66 oMa/1VFXy+THz5WtX9Pv5+h/lZn1yVb1miLtQLueNchM3UqjnE8VK+Lrp9l8AdqKG8 bxVd8V1DQEGLD8bexSfbqdXI6iyLTuIH8wDGSAwK8kwaQ9uKl0OHcZEqWNnogotGfr HkMLklu1eRbRSlU9OD4TNxiqb7nuVI7K4we3NHhhEAXsMr/X0F6r/bG8zokaU052sc nUxUgwa4LAVh8ideLSiv7yVMlmqQKLqib2U2W8a7Yeju2fuk3BXmeyM4Mvo2cuQ5sE 3E2H3TV5eC4Sw== 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 v6 6/9] swiotlb: Reject misaligned restricted DMA pools for CoCo guests Date: Fri, 4 Sep 2026 16:04:49 +0530 Message-ID: <20260904103452.1197239-7-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260904103452.1197239-1-aneesh.kumar@kernel.org> References: <20260904103452.1197239-1-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 f8936b03d942..d1bd06be628d 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -2037,6 +2037,20 @@ 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