From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793810963; b=0cAWIKVcQU3BcH6c7QTjLP8E+J9R7zTIrErh/JHrQxkTESkK0U4YyATXgSLfA+NZVDd8 hf0WFArZnk3H8gKF7uKL2f1kqSZijonP+HreFXe0Qkuz9mhQ37etyCtu5Aj61tTwnPwIi CsP7HIYr1T9h6l4lnapFVWIKQgCwXWvzCY+CdOmwZktk7UeWW0fMYLWlMglC1sMTTDGZr OZcxscJ+ZUn/9CvJky44NXR3e+YH8JqjKDfY402KthIKTqIuL9r6lZZYn9l5ZLoMQO7vW AOfK7NfaY4Lp0tCsYe1u9Ncue3icGrpwE61oh/l44qfml9rgOX3g1gRxMJYSfPNy75g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793810963; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=E/8vjYvtupLf5v8TU9CZJ1WziBquBZCxwcYljZ5lOwY=; b=R/GSEkE1LQg1XMg2FDKbMbqvVC2yzdbQJ9qT5pqWtBb2cEEtlF94bOtR+lwNU+dqm6X5 F3vgKk4EGk+4knLO649ZfZQT23MWjpGd1U9VzWMPL0dgjhSFXBTgVVo5WmDcTIbY5piWt KQXfNmbSoO6ehDALwRjcWre09AroX7f83b3Mw7b/98qbX2rdw/hcAXTZ1ZlqTugrxnPxu 2AUTgg0fb4X8JqaC5L1dEV6aCMhAE23d0V4X1uQFP8rvBzpdmKTLjt6C5mcTNT2xzpHHh 41OTtUsHl+LH4qSwCnAbSTeWN8g5PPSlaRoWPxAlNI278hzdfGfbVpjvfbsrRKV3h1g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ZaU4mJTK; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D26460A261C; Wed, 4 Nov 2026 16:49:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ZaU4mJTK Received: by smtp.kernel.org (Postfix) with ESMTPSA id D93C01F000C1; Wed, 4 Nov 2026 16:49:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793810962; bh=E/8vjYvtupLf5v8TU9CZJ1WziBquBZCxwcYljZ5lOwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZaU4mJTK07JhJXoOkHugFNOLKSBOtcBwxVlKLdiuNzvBXN3LpTwlbBjFzVqSVbTH5 LuzRV8aOWucDBQ1u9vOK0c+4vhcf/3rYEbeq8jcehdhHJ6lF3LgdylELGHFOcisJ7t Fy+EAPnct469u07A8EYfuj2ozRASkB7gtHRUuDSp5vUkpujtSRh3FPhlAjA7Dw+UgF YacoSPx62c9Q2O6xn7F9aYhQ6JDOUxRkw28L8HkO5uZtIP4e4Ox78fAStd0D5p6eth mxnUf4FsSSf4xVn8adZv6TbiNv124uPo6C1aJORBOTSNnHWHbDc7S4c3yUtm0rdH2F Ahf4K0XkiJutQ== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Andrew Morton , Baoquan He , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Catalin Marinas , =?UTF-8?q?Christian=20K=C3=B6nig?= , Jason Gunthorpe , Joerg Roedel , Marc Zyngier , Marek Szyprowski , Robin Murphy , Steven Price , Sumit Semwal , Suzuki K Poulose , Thomas Gleixner , Will Deacon , Russell King , Benjamin Gaignard , Brian Starkey , John Stultz , Mark Rutland , Radu Rendec , "T.J. Mercier" , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Ritesh Harjani , Shrikanth Hegde , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Kiryl Shutsemau , Rick Edgecombe , "K . Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Paolo Bonzini , Vitaly Kuznetsov , Andy Lutomirski , Peter Zijlstra , dri-devel@lists.freedesktop.org, iommu@lists.linux.dev, linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev, patches@lists.linux.dev Subject: [PATCH v9 09/14] swiotlb: Reject misaligned restricted DMA pools for CoCo guests Date: Wed, 4 Nov 2026 22:15:50 +0530 Message-ID: <20261104164555.3555725-10-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261104164555.3555725-1-aneesh.kumar@kernel.org> References: <20261104164555.3555725-1-aneesh.kumar@kernel.org> X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A restricted DMA pool is a firmware-described ownership boundary. Unlike a pool allocated by SWIOTLB itself, its base cannot be moved and its size cannot be rounded without claiming memory outside the reserved region. Confidential-computing guests may require private/shared state changes to cover units larger than PAGE_SIZE. Passing a misaligned restricted region to set_memory_decrypted() can therefore fail. Validate both the physical base and the complete reserved size with the common CoCo shared-range helper before allocating SWIOTLB metadata or performing a state transition. Perform the transition through cc_make_shared(). Cc: Marek Szyprowski Cc: Robin Murphy Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/swiotlb.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 36fbec2241e4..a3fc33c54cec 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -2011,6 +2011,14 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, return -EINVAL; } + if (cc_platform_has(CC_ATTR_MEM_ENCRYPT) && + !cc_shared_range_valid(rmem->base, rmem->size)) { + dev_err(dev, + "Restricted DMA pool must be aligned to %#zx bytes for memory encryption\n", + cc_shared_granule_size()); + return -EINVAL; + } + /* * Since multiple devices can share the same pool, the private data, * io_tlb_mem struct, will be initialized by the first device attached @@ -2044,8 +2052,8 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, int ret; mem->cc_shared = true; - ret = set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), - rmem->size >> PAGE_SHIFT); + ret = cc_make_shared(phys_to_virt(rmem->base), + rmem->size); if (ret) { dev_err(dev, "Failed to decrypt restricted DMA pool\n"); kfree(pool->areas); -- 2.43.0