From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 4093E31064A for ; Mon, 5 Jan 2026 08:22:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767601380; cv=none; b=B+XFRMAUWSYKncr9XlujyPczdKEwDam5ah1MnJKZ/51PyBa+qGS2J1LvIrLGV5lC0OI8KPjsMeQVmsD1f8fCLkzEalgzA6mae/TrUGn1o7Fu1kyL3myBXqpGblO4Q+lEZnn3yiJelu7Dz44u56lI4nXzq/Y3aVcs+HdVpdvf+pk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767601380; c=relaxed/simple; bh=1rF+5o+RxfvaZWaK/37ivP7Ic43xgdCjtd7a083Lyfc=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=Nas3WRBmyvApbTyNTfcvqwNcjj/s/jNgDQg2Er2IfS4IADgT09IhIBpECK7L2/GUX6mycGZljF77iNwpZ+UMorNnAKE5cA81PQJJEH9ianWB0BoglWHkb8A9dW2BgoVwfqdwh0yCroEdG9Qhis3o3ei87X9SWouXR8GlHwpNdEs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=OVpQPRID; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=aFnAwaAK; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OVpQPRID"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="aFnAwaAK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767601377; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=++MSvPbbaixtOH+VkhbpdT2tKuVIlO7zEYO24bBcB2o=; b=OVpQPRIDj5fXqBg9A/hP4xVzLw8MYfD0RyVh4Bk3mpjidMcWQVlxb6UWCkDP88f6dbWF3F SvhRQ9LrJEXf8a4sePL5O5s/gicfHgSC7GHHwSCZoSo54sbVX2pEdbD1EQjHEf1CDNwLaQ fzhYe/ROFifr2sDRbPyDY0j+oMXFN/U= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-689-6fr_u6vYPc-1pOvApwUVvQ-1; Mon, 05 Jan 2026 03:22:55 -0500 X-MC-Unique: 6fr_u6vYPc-1pOvApwUVvQ-1 X-Mimecast-MFC-AGG-ID: 6fr_u6vYPc-1pOvApwUVvQ_1767601375 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-477b8a667bcso184528695e9.2 for ; Mon, 05 Jan 2026 00:22:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1767601374; x=1768206174; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=++MSvPbbaixtOH+VkhbpdT2tKuVIlO7zEYO24bBcB2o=; b=aFnAwaAKLu7zAhMf+1ZJkNmIT145xhfGYevQ+uwx4Dua/sOWHk6GFH5sAFW7CCCMFZ 0cya9z65tmnNTyvX8ggutiwfatl5uHID38vuE/UmtJgcJ4jlVipRomZHHhHg4cIFInDR 6fxzl+4UMlWcfjaV+B80TtPV4bNU/SlsWfmvdpHWeonjuIye9gFLQHa5ezv0cGiFYn1M uPIv55VhcCeX+mAns+hZrOKdH37ATwCzhEooCCd6oH/t8AoUlfs90mZBEvbeNgJbXLLq GSSl7PCZXbESwGZq0n141aAGd5Eg/NVjFtyyDdOp5ijpOTk8+jF8eE6VPD6Wf6vrFLzF aNPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767601374; x=1768206174; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=++MSvPbbaixtOH+VkhbpdT2tKuVIlO7zEYO24bBcB2o=; b=wIDpSP23iOjJrT3nTltxNlxhS3b/HkYJXipUc4V9I+AZFHdY6w0Ppob+QMDaZ3ULE2 9bVslgo4tsbemnfHUZaLx26kCHUhspoKqZMBRRZRB3Apj8SyZyEYKKtH3Vc0uXrZWCQV aqA51VifSdLumcHg8Ed/4nrbH2nEEBWT3ZLs8eHXhqF6PyEywelj3nIJ8JLh/eqjhJcg qo7YTuXVcKRvVYTkjwpT++7rtCSf8smAicnev8kKGe3Bmkz8FtviUSpfs9u0/g2p/HhC Xe+Xz0I3TNkk0lYPMvk3rDvFXS0hP1TXyipwXPT5JDZMp93/QLpHjy5aGPit3hEGSAs0 0pDg== X-Forwarded-Encrypted: i=1; AJvYcCWE6+djqBXXzsRCOc6Uwevw2JUfQhoBFCCgs8BXGDziXHVh4zD6fdfxgGNE4N2FWEB3/iU=@vger.kernel.org X-Gm-Message-State: AOJu0YxcVIbzXXPYUIfsD5RnfXFA0ibUEdrnfejQWnmE17dK6hFo6sfq vDRpNE0wLCr5tQvFp7GQf39ZQPCIpiz0CEvdOQgfmon1tfD4pJ1SbOZSxIRD/Q9ft+7ckN7UrJ+ hRbns9tTcyMq26ddIu+1i3mDHiKjxrEAMOqqpHjSs+WBBqeZSj7gO0A== X-Gm-Gg: AY/fxX4RRgFpWa/uymTOQ6kII+6BGvlPUTPSW05ZNu01hExcVYg0qQj2bHVz49JO90J KSR/XIp45REOgsyFtEl7am0lFAREfd6ulQ9LCybPtcS25otjljKNh2Lsn39f0yWaRREoRoWF//8 F4WHNeKeI3qLe7+w5ary3WX+2EeY9++KJtmh6KEn3pmHijIxUtpEjIJSrSIkL/0lMH67OZRiJhi QFGY7sjh86cVz6LyhaY/O+oBtSmjC/hQh72KqitoqgM4ZNH+EWhbcpqbb+pz8Ofq3qrvnYjL5ld KPTlQXiSTVib153hlQzMtWeTP1eq646i4xPljTzNUqAsaKcueSMc1eOi/sJLV5BfBY9WARItLLr pYxfUwdvKKo2qlQegoXHM3Y8SNaRiROlQdQ== X-Received: by 2002:a05:600c:4ed2:b0:475:e067:f23d with SMTP id 5b1f17b1804b1-47d1959eaaemr640737525e9.25.1767601374456; Mon, 05 Jan 2026 00:22:54 -0800 (PST) X-Google-Smtp-Source: AGHT+IEXw2Pw2EoWGIJB0fy/EdgimCoNIlh1q5tf6OTMnGxG74FiSYxf17YyIIU15mHj+ck3a5eDtg== X-Received: by 2002:a05:600c:4ed2:b0:475:e067:f23d with SMTP id 5b1f17b1804b1-47d1959eaaemr640737005e9.25.1767601373905; Mon, 05 Jan 2026 00:22:53 -0800 (PST) Received: from redhat.com (IGLD-80-230-31-118.inter.net.il. [80.230.31.118]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47d6ba30531sm56554215e9.1.2026.01.05.00.22.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jan 2026 00:22:53 -0800 (PST) Date: Mon, 5 Jan 2026 03:22:50 -0500 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Cong Wang , Jonathan Corbet , Olivia Mackall , Herbert Xu , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Eugenio =?utf-8?B?UMOpcmV6?= , "James E.J. Bottomley" , "Martin K. Petersen" , Gerd Hoffmann , Xuan Zhuo , Marek Szyprowski , Robin Murphy , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Petr Tesarik , Leon Romanovsky , Jason Gunthorpe , Bartosz Golaszewski , linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, virtualization@lists.linux.dev, linux-scsi@vger.kernel.org, iommu@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2 00/15] fix DMA aligment issues around virtio Message-ID: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Cong Wang reported dma debug warnings with virtio-vsock and proposed a patch, see: https://lore.kernel.org/all/20251228015451.1253271-1-xiyou.wangcong@gmail.com/ however, the issue is more widespread. This is an attempt to fix it systematically. Note: i2c and gio might also be affected, I am still looking into it. Help from maintainers welcome. Lightly tested. Cursor/claude used liberally, mostly for refactoring/API updates/English. DMA maintainers, could you please confirm the DMA core changes are ok with you? Thanks! Michael S. Tsirkin (15): dma-mapping: add __dma_from_device_group_begin()/end() docs: dma-api: document __dma_from_device_group_begin()/end() dma-mapping: add DMA_ATTR_CPU_CACHE_CLEAN docs: dma-api: document DMA_ATTR_CPU_CACHE_CLEAN dma-debug: track cache clean flag in entries virtio: add virtqueue_add_inbuf_cache_clean API vsock/virtio: fix DMA alignment for event_list vsock/virtio: use virtqueue_add_inbuf_cache_clean for events virtio_input: fix DMA alignment for evts virtio_scsi: fix DMA cacheline issues for events virtio-rng: fix DMA alignment for data buffer virtio_input: use virtqueue_add_inbuf_cache_clean for events vsock/virtio: reorder fields to reduce padding gpio: virtio: fix DMA alignment gpio: virtio: reorder fields to reduce struct padding Documentation/core-api/dma-api-howto.rst | 52 ++++++++++++++ Documentation/core-api/dma-attributes.rst | 9 +++ drivers/char/hw_random/virtio-rng.c | 3 + drivers/gpio/gpio-virtio.c | 15 ++-- drivers/scsi/virtio_scsi.c | 17 +++-- drivers/virtio/virtio_input.c | 5 +- drivers/virtio/virtio_ring.c | 83 ++++++++++++++++------- include/linux/dma-mapping.h | 20 ++++++ include/linux/virtio.h | 5 ++ kernel/dma/debug.c | 28 ++++++-- net/vmw_vsock/virtio_transport.c | 8 ++- 11 files changed, 205 insertions(+), 40 deletions(-) -- MST