From nobody Tue Nov 26 17:41:04 2024 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 62A1C1DED56; Thu, 17 Oct 2024 13:15:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729170919; cv=none; b=uKQNl4nejnhjkAAg2QWSqeSSTlzYVVQfwJ3ybZ8wJE1KOea6l70FYirnrQpS1rR0rFYRbS9dctDuk/3HR7vs/Ggw53vKZ6NdeQsVmSeysiZFibw8yslu5z+BZ3b31/sMM6feWX0Bv9uWB0O8s9jeJaJe+no1FVFS3dIjgaNeY7c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729170919; c=relaxed/simple; bh=YCDwYlF/ESxK0pk7bzv3GjtnsbtXQunn8pRpwWc/sbA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cjpNB6j6PMq8p1bQQBrvJNEpdmsysFT9pjK+xDXCa+kYKFUyn62kXBc9trpuhcVObIjUPSqmk1+9lXxxTpK8XWiOINsAQMB8jHV/Luq59rLHVh+aTto6OldxDLTia39zVmvA+p7V28puWmd1O3VXjuqtn1CDvAdYHipM7nqlgKk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 89C6ADA7; Thu, 17 Oct 2024 06:15:45 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.62]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 380EF3F71E; Thu, 17 Oct 2024 06:15:12 -0700 (PDT) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" Subject: [PATCH v7 07/11] arm64: Enforce bounce buffers for realm DMA Date: Thu, 17 Oct 2024 14:14:30 +0100 Message-Id: <20241017131434.40935-8-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241017131434.40935-1-steven.price@arm.com> References: <20241017131434.40935-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Within a realm guest it's not possible for a device emulated by the VMM to access arbitrary guest memory. So force the use of bounce buffers to ensure that the memory the emulated devices are accessing is in memory which is explicitly shared with the host. This adds a call to swiotlb_update_mem_attributes() which calls set_memory_decrypted() to ensure the bounce buffer memory is shared with the host. For non-realm guests or hosts this is a no-op. Reviewed-by: Catalin Marinas Reviewed-by: Gavin Shan Co-developed-by: Suzuki K Poulose Signed-off-by: Suzuki K Poulose Signed-off-by: Steven Price --- v3: Simplify mem_init() by using a 'flags' variable. --- arch/arm64/kernel/rsi.c | 1 + arch/arm64/mm/init.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c index 3e0c83e2296f..a23c0a7154d2 100644 --- a/arch/arm64/kernel/rsi.c +++ b/arch/arm64/kernel/rsi.c @@ -6,6 +6,7 @@ #include #include #include +#include =20 #include #include diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 27a32ff15412..d21f67d67cf5 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -366,8 +367,14 @@ void __init bootmem_init(void) */ void __init mem_init(void) { + unsigned int flags =3D SWIOTLB_VERBOSE; bool swiotlb =3D max_pfn > PFN_DOWN(arm64_dma_phys_limit); =20 + if (is_realm_world()) { + swiotlb =3D true; + flags |=3D SWIOTLB_FORCE; + } + if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb) { /* * If no bouncing needed for ZONE_DMA, reduce the swiotlb @@ -379,7 +386,8 @@ void __init mem_init(void) swiotlb =3D true; } =20 - swiotlb_init(swiotlb, SWIOTLB_VERBOSE); + swiotlb_init(swiotlb, flags); + swiotlb_update_mem_attributes(); =20 /* this will put all unused low memory onto the freelists */ memblock_free_all(); --=20 2.34.1