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 D9A8E2E8B97 for ; Tue, 30 Dec 2025 10:16:41 +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=1767089803; cv=none; b=D4rPDN3pNODK1pO0BtS1cBXMGROTMSuPK+y5tBIVQGVpLCXZPqt+F0qTH8XwxVZxhU2dahhO1upb+A4w7r+hh176lvQVRmq4Whz6K+zwgeIbpIUr49T24NS4KY0wUvPItxMidjjHyhhqIrbHl6LScRuH/QhbvnTXL5E2DLYn18Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767089803; c=relaxed/simple; bh=RzxSFhz+bpkLtGdr/5qvrDQOf7DHug0oDxHEj4NfN04=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uZscYjrCgef2TxF435b8o9Q/Gp57nMc64gm1kk3dNDyUIXDK7hbrDMGU2DdzkxvnML9IPCG9ik+L/hPInJQMYWt0f4qyQq5ISmBH4E4EGCXbdrnriV4dZ6vXaKBECnmcuC08lFQwFxOm4aOE7KsuRuqymTiZd235iPwHpA+R2CE= 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=gp+/QrIb; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=A/hkwEx4; 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="gp+/QrIb"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="A/hkwEx4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767089800; 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: in-reply-to:in-reply-to:references:references; bh=qjCbMizY1BaJF5yBWOLXV7DyUl9vbunxYIEFqfWmhYA=; b=gp+/QrIbF1nc+WyvdgEXty3YI5FINourt6mIKYBAsBIlirZqD3Wv6GDJqWKr+sOkvIVh5s dxF4qPLzJl4rAKwYN2oF5C8IJzaUmBXxK7ZXJ8WfrH56+Q52ofgILo/Kz+PUAPW0lNSNS6 ZdoLeuRp1ebeR+fGPTrAvbpiSTvmlhk= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-483-vCmfTHElMjiIlo5GHtYdzg-1; Tue, 30 Dec 2025 05:16:39 -0500 X-MC-Unique: vCmfTHElMjiIlo5GHtYdzg-1 X-Mimecast-MFC-AGG-ID: vCmfTHElMjiIlo5GHtYdzg_1767089798 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-4775d8428e8so82533175e9.0 for ; Tue, 30 Dec 2025 02:16:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1767089798; x=1767694598; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=qjCbMizY1BaJF5yBWOLXV7DyUl9vbunxYIEFqfWmhYA=; b=A/hkwEx4WZZqbWGO/MKIo5PbfxAPOdcLiTbBHSaSP0SHg8S8cwWpKHuScFjvBz5LtZ dgnv05gLf1QD3b8feoewuk+ryDTDw8j6yHJeDklMZHC8r6zeYdjm81Ir1h7upjeGquqv QUrQerqcKtaD7jdpCwenPlnJLZ4Ca0/zGIsfxbs2cqoul+hR+lmjc8jXK/XKVsd5MdH1 WX2jOAqrnFOZ2EK/DkhSM9CCYzK8dDDTjUha8Re4VFbih2TgwK4j5ZPARaR8idthYOiq YnmhyvNLtrrSxftR6dY5fGO3J/oV9LVG1+NYTKI+FwQtiZn88YIoywesqIICOHIBV1xb ZGdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767089798; x=1767694598; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qjCbMizY1BaJF5yBWOLXV7DyUl9vbunxYIEFqfWmhYA=; b=Uyb7Ltx2tDJHYMBcX4Bj06jUciK/JfS84z/hanUn3bdayASby5Dt/t742OnPP0uWF6 4raZK+W8sQ7cQ6Ww4fnMNuH3eORbZvmg9+fERxk+wDWwR3UveXBydnD4/p+1mMrJp6nN QAe0AS3RjnBs9WlmpG3izGe5PTF8g6Ea9YFvpTH1pGnT9PYCZJLq6kiyLhmnHom9/aD3 69oUpqJ8CswKGvpHrhRqrkoyLU0xdddWfNjq2JEL6hK22HHioHjBTp8dXXR0pdzPqWOd AORwUuqSApPvgBup8oUR8Y5rk/52kS84+EIRIwfdZCW02wqIxsgpU4aQyYvrkeAqDcE1 g38w== X-Gm-Message-State: AOJu0Ywz/6k6DOjeIHEo2EYF4gFyXKgVFM0TS2EGMOsuUiM9bGd92Po5 euHZdldNEThN2IbRMdXLmuC2aZ7W8KlgM69FT5liigv/JSe2AfPKQecUBkX1vXpCggNVY7kB933 QtDVzz6Vod4jwH/iAJmQQbVeV/5n27jahLV+0g0ATrTGrdAWyc3SBzMhZMJh9CeccNHWeqvp33w ub0SHMzFT37N3mRgo/LiMoHt9FMuL3HoR5rOdXroAlkuc= X-Gm-Gg: AY/fxX6EW3BcHFD+PKX1NZI38aPIl4ZdHjFknBiBgsbyaoBygsJx0i6Fjook7J/W941 3pTR7ZO0QnX7Yps7Iq+X0P27n48s5vHCKlu4Ce0FLv839EkiWYa3vBY1NQFYYqeMLawp81cgiux 7tlTGh8tSvBRhvSpCJAmcqbdQCllNXnmaFy+MDc9KkcFNMrSmUA6QxI0VtbJDo+qo6SJojG5RX3 LwRGx8gjhXzOYqfz6C7RljiL3Gk24sPiosAO75xYvijEXbrDa7dmoLItyjDBtN8nY6v3LwC+G2g 0reQ80ZiAq7z3zoZKZ/r6Hb2bVRoHkO5M6Jw61/+RDC7GJLfXKNh613VfBbl5SPI1BuCn2/REc6 wAXoH/f9gTUgM7RoAwvRCTVYiTwhliFPv9Q== X-Received: by 2002:a05:600c:620d:b0:47b:da85:b9ef with SMTP id 5b1f17b1804b1-47d19569c23mr469752835e9.16.1767089798022; Tue, 30 Dec 2025 02:16:38 -0800 (PST) X-Google-Smtp-Source: AGHT+IHj3WKIKEzUGPKu3zdwQlyOBMeOTgJhitK/YOLHPeOIUg2zxiErnT0jngxXmWGMEmg7Rb+0jg== X-Received: by 2002:a05:600c:620d:b0:47b:da85:b9ef with SMTP id 5b1f17b1804b1-47d19569c23mr469752175e9.16.1767089797499; Tue, 30 Dec 2025 02:16:37 -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 5b1f17b1804b1-47be279c5f8sm610551235e9.9.2025.12.30.02.16.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Dec 2025 02:16:37 -0800 (PST) Date: Tue, 30 Dec 2025 05:16:33 -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 , 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 RFC 09/13] virtio_input: fix DMA cacheline alignment for evts Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent On non-cache-coherent platforms, when a structure contains a buffer used for DMA alongside fields that the CPU writes to, cacheline sharing can cause data corruption. The evts array is used for DMA_FROM_DEVICE operations via virtqueue_add_inbuf(). The adjacent lock and ready fields are written by the CPU during normal operation. If these share cachelines with evts, CPU writes can corrupt DMA data. Add __dma_from_device_aligned_begin/end annotations to ensure evts is isolated in its own cachelines. Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_input.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c index d0728285b6ce..774494754a99 100644 --- a/drivers/virtio/virtio_input.c +++ b/drivers/virtio/virtio_input.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include @@ -16,7 +17,9 @@ struct virtio_input { char serial[64]; char phys[64]; struct virtqueue *evt, *sts; + __dma_from_device_aligned_begin struct virtio_input_event evts[64]; + __dma_from_device_aligned_end spinlock_t lock; bool ready; }; -- MST