From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout-b8-smtp.messagingengine.com (fout-b8-smtp.messagingengine.com [202.12.124.151]) (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 8E2C7261B9E for ; Tue, 6 Oct 2026 00:51:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791247884; cv=none; b=UvT/KpwAEG03Mgaq4Cox20ymxcjOe11joPkROmHFHN/wD0wkdxCtsRqFhMDoow5YDy5VAr4QwWLBM1Ig+H6MhwAoZw4/WsB72JNvDJaj6c7cmqmqEJzctVqlcl+2HIzVSNq3f1Q8bZ4+trIDC8a6trZtVk7+BVaT3T0WOn5oMBs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791247884; c=relaxed/simple; bh=DbE2ljPHR9RLBxRiQC0D1Il93+Qii2jUhAcHu4S2aWA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Kua7sjtAGr8drcLCQtEle/8Arv7Nly50fbcGq0kTOvaNDdqqQYk9upegqcLBHwi/YDPlGIHWhgq2rrXcX3A2SBUk75x6vrgiWtSPGkEGf1nFb10MhGYRpSB9PJOnt+4ZiHvIxJow9p1ZA5EE1736nXCDVd8PkT3aG/wsWCBQil4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=invisiblethingslab.com; spf=pass smtp.mailfrom=invisiblethingslab.com; dkim=pass (2048-bit key) header.d=invisiblethingslab.com header.i=@invisiblethingslab.com header.b=OxLZv8Tz; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=PM4JXWyL; arc=none smtp.client-ip=202.12.124.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=invisiblethingslab.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=invisiblethingslab.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=invisiblethingslab.com header.i=@invisiblethingslab.com header.b="OxLZv8Tz"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="PM4JXWyL" Received: from phl-compute-02.internal (phl-compute-02.internal [10.202.2.42]) by mailfout.stl.internal (Postfix) with ESMTP id E9C341D00097 for ; Mon, 5 Oct 2026 20:51:21 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-02.internal (MEProxy); Mon, 05 Oct 2026 20:51:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= invisiblethingslab.com; h=cc:cc:content-transfer-encoding :content-type:date:date:from:from:in-reply-to:message-id :mime-version:reply-to:subject:subject:to:to; s=fm1; t= 1791247880; x=1791334280; bh=tRmGBPddwRXIEIkuPN35f35fGROq9M41+zS XYOhRKVM=; b=OxLZv8TzQnJsApYqfcRLiFoDtaZz7z3fuC4g0PvVjV0PXoeUa37 lGccsQdmpd/IrAb/8Cc8w0Oi5tG8NPPQQQdSrh2O/NexetpRZLGf/T4Ueg2+xlpa SesEjf48ilsGa5ggjjniRNq3boeJa8l803Ff5TTLnxoGNzRfRCsuGyFf2tGG30zM jUwsBjq5EXBGGzB2wTy2oBZfFc5UBd/XC1o0jug6LqjydDFWrSsgVJXSTytWPcoI IvTStnK/IVXJhXiiplee8uiu/70qj7bwqi/B/UrDrqHxkmWbBmeEakojZJn8z0m0 Q+LvvUtr7rzdA3sZ5YPlyRxPKFrfIuJ53vQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:message-id:mime-version:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1791247880; x=1791334280; bh=tRmGBPddwRXIEIkuPN35f35fGROq9M41+zS XYOhRKVM=; b=PM4JXWyLOgavv4Ys8VgoNmdCyNG8yv99fshlaCPDiDwsyPTzQqC TxwsqY8XkUUYYFrWYIDZ26nvhM5TD1dw2o2dd4zdNoGf6xZkr1f8RclAV+8Lyeqa rEH+5bbnw3Bb8/rpgqbn1ZkehX9JNonU67hPrRnSJXQytJORHjwc2m/SvVMk920e 1rEl0CnPPufiV8CE47UUo6md9tHlJVbiB1YVVIrGizUlyjOJdKn7Nc+uHOr92IQh Uo5Wt62TEoJpHRGmw+8VphYrVZVV8qbOhldGNy6Q+CGmqXGsI9V0rZY+jYdci0m6 4HTBiYHYx4/pNkQ2GJyRF8Hsnl3KY/1Eldw== X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-09-30; sw=lmtpprox; action=sign d=invisiblethingslab.com a=rsa-sha256; DKIM2-Signature: i=1; m=1; t=1791247880; d=invisiblethingslab.com; mf=PHZhbEBpbnZpc2libGV0aGluZ3NsYWIuY29tPg==; rt=PGxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmc+; s=fm1:rsa-sha256:So3m5pat1M53SmCIQVtFO/J/qByHSIsLNsBkqfLvlsyMU9q PiE8/zdvqLtYx657LK/vosBFSGpAdlOJ+aLmwLRcnEkNfrpdyddAC6er6Tg0xkJM Y1r19atzn2SOlod3Sm5zeHMMz3RzpFSbKBWaGHzYuh95Kvk0f3T1AdpE7r9dENTX W3oPNboq+2fFm43GFZrCUpAWYmP9G5tOBs/SCwzWy+GdwWk2fxL/mYKfFi52VceD zj+jCs5qf7i2pbJxXei6WQ/QwZCS4vZMjXAMXmGIFdEwOH4+gq8TWcpDuF3o6Urj /O1dpgATJvSgXXR1gFxg0JAg85ogm9NWYnP62fQ==; X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-09-30; sw=lmtpprox; action=mi-m=1; hc=9; hn=cc,content-transfer-encoding,date,feedback-id,from, message-id,mime-version,subject,to; Message-Instance: m=1; h=sha256:2bupfxoc7c/W78shAkUTwaYLOwOELTJM7wttvyVs7wM=:DbE2ljPHR9RLBxRiQC0D1Il93+Qii2jUhAcHu4S2aWA=; X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTGDeGecfuOBqBR+BQhzcXn/vNYPPEmBB26O+qh7FZR7AUWqdQtYPjhC6dsLaDuBea IeTTQ8cmgK80NNnBDqKATqjtVF4/aX3CSonUXyU8NmWyhcyIhTs/9zvqYDF0sB+7+ZIQdM 9BowT4dTsQLooVUdU9xViDIHD23gTeHkjfPMGpOvGX4nslU+OWiL1aI8E3CWpnfnx3JzSv 2Mfm2NUZXTHi96BFZEOZzjtluW7L83Db8YedS+pGUpiqrYrNSUgOfmbo7kLzifDvFwePml 3SyuoIORcUukCr/0RuDX7tj9pdkGzDL4n/3wFyh0IdxaaedWq8etqdwyR9PF8lKHDgYuP0 JqX6/erQXDHZNY28l0+SxIWThsa633lKoUdWDbeHfliIx4PBhJX553VLMcZ6QjnySIWH9f MCctceavToVfBDwR80C7wEAbrqgadx4IShdfXGfXppcC7rsUE/caKhn8OD4fa7LLwMPKxV cPGtmqHqosDZw4eaBKVIjyYhxJE3YniwbA9HJcsZcOrUPwYph25aVe0K7qEDZzF4l2RoMP c/NMssbwZInDhFt38or4vj7DMByUMWp4m/lsO8flGPn8JAC+I7U/fcc/pF5zUqgJS5AnfK 5bOV+BI5cxaEor1igM/TmaO5VNjIA61w/g2QIlboIVeR6vdR6cswUpgKyd0A X-ME-Proxy: Feedback-ID: i001e48d0:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 5 Oct 2026 20:51:17 -0400 (EDT) From: Val Packett To: Gerd Hoffmann , Vivek Kasireddy , Sumit Semwal , =?UTF-8?q?Christian=20K=C3=B6nig?= , Philipp Stanner Cc: Val Packett , dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH] udmabuf: Disable the list length limit by default Date: Mon, 5 Oct 2026 21:48:53 -0300 Message-ID: <20261006005053.2245156-1-val@invisiblethingslab.com> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Shared memory buffers for software-rendered GUI applications are often large and highly fragmented in memory. To get a shareable handle to such a buffer from a guest VM, a virtio-gpu device backend can use the UDMABUF_CREATE_LIST ioctl with the memfds backing guest RAM and the list of guest physical pages sent by the guest driver. That list reaches 80K entries for a maximized window on a 4K display! Like 44e9eb5a7621 ("dma-buf/udmabuf: Disable the size limit by default") did for the size limit, change the default to INT_MAX since the amount of protection provided by this limit seems dubious. Signed-off-by: Val Packett --- drivers/dma-buf/udmabuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index df6dd0046242..589031133588 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -16,9 +16,9 @@ #include #include -static int list_limit = 1024; +static int list_limit = INT_MAX; module_param(list_limit, int, 0644); -MODULE_PARM_DESC(list_limit, "udmabuf_create_list->count limit. Default is 1024."); +MODULE_PARM_DESC(list_limit, "udmabuf_create_list->count limit. Default is INT_MAX."); static int size_limit_mb = INT_MAX; module_param(size_limit_mb, int, 0644); -- 2.55.0