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 C6393CD5BAF for ; Fri, 22 May 2026 04:30:39 +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=yz/sGqfqBvDBAnbbNxVoDgt2HJ5Km5y5+l03PeTOpg0=; b=m7vmIQp1uDeE6M5mY54yEZq7A5 W+SPtxu/7ap9iyhArgJIsUq+ktLwUK3xyKwCxx2R8Dec2g++J+lWuIRbt0xbPxCy6Fg2U/66MPmQk pRsJsv/yN7wZ/1h4Ww/jeaAFxkUS+rNk3cvIEC3H8dCc13PGiJOyGR/nNORNDtd9tpcRw7lkTNar+ LOm+pJc7exm0e4EQJhBN7eNZBr18Ws4HTmTpjlR0ZEDu8Uivv2HuJNqSqms15aICid/U3XKGtl/kg xTmRn0WcJWQP5LVdHw77r5dP5KZMFGGJiFsLNLOEJtvrfYGzuibJe8mtbzGne/nxOPPtAsd4GUYBW 2RT3YoaQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQHWr-00000009kK7-3UBy; Fri, 22 May 2026 04:30:33 +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 1wQHWq-00000009kJM-2aaJ for linux-arm-kernel@lists.infradead.org; Fri, 22 May 2026 04:30:32 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 10E4360172; Fri, 22 May 2026 04:30:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A8D31F000E9; Fri, 22 May 2026 04:30:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779424231; bh=yz/sGqfqBvDBAnbbNxVoDgt2HJ5Km5y5+l03PeTOpg0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KQjop4pcYeqjmueQHL6P2mhQEsUyfDraldU4rC+JGeFegMHBg4OMorAFtxGgqLE2n Nohd/Gbt0+rx2uoWWj10KHilY7YqucmZZXGzveHLXyw1pBrFaggMKdiAY8yY1srMu7 ooV9OIFMhZg6QTxhWR8jcPB5g5pAf8mUStqNwT5js+Ayc1OzB/1yrylTUfQSgkMRM2 p4n0RF5xbk8KBT633zY2em/290EhYI35ytUCo0aSb5/6Q8gmtz7RWklKsRqauwayFA yi2WTuWw/ssg0IXD1Zp9r1cE0vlGja+2f5fRu9n4wwXO4NyCbQ4Wikc/CqNrobMtn/ h8OXSqaO7fCRw== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org, Jiri Pirko Subject: [PATCH v5 10/20] dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHARED Date: Fri, 22 May 2026 09:58:05 +0530 Message-ID: <20260522042815.370873-11-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260522042815.370873-1-aneesh.kumar@kernel.org> References: <20260522042815.370873-1-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 Teach dma_direct_map_phys() to select the DMA address encoding based on DMA_ATTR_CC_SHARED. Use phys_to_dma_unencrypted() for decrypted mappings and phys_to_dma_encrypted() otherwise. If a device requires unencrypted DMA but the source physical address is still encrypted, force the mapping through swiotlb so the DMA address and backing memory attributes remain consistent. Update the arm64, x86, s390 and powerpc secure-guest setup to not use swiotlb force option Tested-by: Jiri Pirko Signed-off-by: Aneesh Kumar K.V (Arm) --- Changes from v3: * Handle DMA_ATTR_MMIO --- arch/arm64/mm/init.c | 4 +-- arch/powerpc/platforms/pseries/svm.c | 2 +- arch/s390/mm/init.c | 2 +- arch/x86/kernel/pci-dma.c | 4 +-- kernel/dma/direct.c | 4 ++- kernel/dma/direct.h | 45 +++++++++++++++------------- 6 files changed, 31 insertions(+), 30 deletions(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index c1b223e7cc8e..a087ac5b15f7 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -340,10 +340,8 @@ void __init arch_mm_preinit(void) unsigned int flags = SWIOTLB_VERBOSE; bool swiotlb = max_pfn > PFN_DOWN(arm64_dma_phys_limit); - if (is_realm_world()) { + if (is_realm_world()) swiotlb = true; - flags |= SWIOTLB_FORCE; - } if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb) { /* diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c index 384c9dc1899a..7a403dbd35ee 100644 --- a/arch/powerpc/platforms/pseries/svm.c +++ b/arch/powerpc/platforms/pseries/svm.c @@ -29,7 +29,7 @@ static int __init init_svm(void) * need to use the SWIOTLB buffer for DMA even if dma_capable() says * otherwise. */ - ppc_swiotlb_flags |= SWIOTLB_ANY | SWIOTLB_FORCE; + ppc_swiotlb_flags |= SWIOTLB_ANY; /* Share the SWIOTLB buffer with the host. */ swiotlb_update_mem_attributes(); diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index ad3c6d92b801..581af1483c42 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -163,7 +163,7 @@ static void __init pv_init(void) virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc); /* make sure bounce buffers are shared */ - swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE); + swiotlb_init(true, SWIOTLB_VERBOSE); swiotlb_update_mem_attributes(); } diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 6267363e0189..75cf8f6ae8cd 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -59,10 +59,8 @@ static void __init pci_swiotlb_detect(void) * bounce buffers as the hypervisor can't access arbitrary VM memory * that is not explicitly shared with it. */ - if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) { + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) x86_swiotlb_enable = true; - x86_swiotlb_flags |= SWIOTLB_FORCE; - } } #else static inline void __init pci_swiotlb_detect(void) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 429791b2599a..9e65c8432b6e 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -702,8 +702,10 @@ size_t dma_direct_max_mapping_size(struct device *dev) { /* If SWIOTLB is active, use its maximum mapping size */ if (is_swiotlb_active(dev) && - (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev))) + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev) || + force_dma_unencrypted(dev))) return swiotlb_max_mapping_size(dev); + return SIZE_MAX; } diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index e05dc7649366..f3fc28f352ba 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -88,37 +88,40 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev, { dma_addr_t dma_addr; + /* + * For a device requiring unencrypted DMA, MMIO memory is treated + * as shared by default. + */ + if (force_dma_unencrypted(dev) && (attrs & DMA_ATTR_MMIO)) + attrs |= DMA_ATTR_CC_SHARED; + if (is_swiotlb_force_bounce(dev)) { - if (!(attrs & DMA_ATTR_CC_SHARED)) { - if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) - return DMA_MAPPING_ERROR; + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) + return DMA_MAPPING_ERROR; - return swiotlb_map(dev, phys, size, dir, attrs); - } - } else if (attrs & DMA_ATTR_CC_SHARED) { - return DMA_MAPPING_ERROR; + return swiotlb_map(dev, phys, size, dir, attrs); } - if (attrs & DMA_ATTR_MMIO) { - dma_addr = phys; - if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs))) - goto err_overflow; - } else if (attrs & DMA_ATTR_CC_SHARED) { + if (attrs & DMA_ATTR_CC_SHARED) dma_addr = phys_to_dma_unencrypted(dev, phys); + else + dma_addr = phys_to_dma_encrypted(dev, phys); + + if (attrs & DMA_ATTR_MMIO) { if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs))) goto err_overflow; - } else { - dma_addr = phys_to_dma(dev, phys); - if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs)) || - dma_kmalloc_needs_bounce(dev, size, dir)) { - if (is_swiotlb_active(dev) && - !(attrs & DMA_ATTR_REQUIRE_COHERENT)) - return swiotlb_map(dev, phys, size, dir, attrs); + goto dma_mapped; + } - goto err_overflow; - } + if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs)) || + dma_kmalloc_needs_bounce(dev, size, dir)) { + if (is_swiotlb_active(dev) && + !(attrs & DMA_ATTR_REQUIRE_COHERENT)) + return swiotlb_map(dev, phys, size, dir, attrs); + goto err_overflow; } +dma_mapped: if (!dev_is_dma_coherent(dev) && !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) { arch_sync_dma_for_device(phys, size, dir); -- 2.43.0