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 27854C5AD4E for ; Mon, 10 Aug 2026 09:13:53 +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:References:Content-Type: Content-Transfer-Encoding:In-Reply-To:From:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9F2+hqEi/pOkUD0Sk5/5UFMk/Jt0LKrILlP4x/Pr3As=; b=J8XVIjJ8w37XDHJ28anb4CuPep 0vbyWef5YmKLB2SW88q7ZZeM4HndTUBh3mKk9X/2VHP+inhyP0Da7lO/F5NjDJHi/2gJ15oTyDeP/ HCjNl1e0iqJL/qnCC3DpYb5n99qDUFGpyXf/dLv0/v11ZS7+DRBKVOPsFH0YJSULT33QO/n+vPY6H LVtGTjwUn3nOAKrnGWPv+NAsZv8ty14XdypygKA5RBNhIE7q3bqnsaYo6B8xFeho2F/re7zdugnsf BBgryJSPL9o19qjKqSlSNsUD9Z1UVw9rCw3a0JpFUawNm+cF2YSQHHb0oz1B1+lSDGrZTVHgcNJVZ kFIE4ihw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtM4j-0000000BNEF-2hV3; Mon, 10 Aug 2026 09:13:41 +0000 Received: from mailout2.w1.samsung.com ([210.118.77.12]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtM4g-0000000BNDG-0kH9 for linux-arm-kernel@lists.infradead.org; Mon, 10 Aug 2026 09:13:40 +0000 Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20260810091334euoutp02b90f2f488c302ac4039b7efbd8aebb04~KZsi7HVtz1748917489euoutp02C; Mon, 10 Aug 2026 09:13:34 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20260810091334euoutp02b90f2f488c302ac4039b7efbd8aebb04~KZsi7HVtz1748917489euoutp02C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1786353214; bh=9F2+hqEi/pOkUD0Sk5/5UFMk/Jt0LKrILlP4x/Pr3As=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=lxfWDNt4pgEBF2hGBprplDfS9ZiG8PU4QIWr1XTy3IRJQST0jDMlcjb6C2xQflNho aen+A3Jx31spZzgUNGO+k3HbMv/jTGuHy0D1yuJ14RYPvP7BOanhJPtyIa25CHs0U6 5w3PfE1mfJVMAAg5BOlPbbbLVO96I2Sq0ySYnDFw= Received: from eusmtip2.samsung.com (unknown [203.254.199.222]) by eucas1p1.samsung.com (KnoxPortal) with ESMTPA id 20260810091334eucas1p1e0ed221ce5794cf7bd02a4bed868a380~KZsiumB1n1295212952eucas1p1G; Mon, 10 Aug 2026 09:13:34 +0000 (GMT) Received: from [106.120.50.46] (unknown [106.120.50.46]) by eusmtip2.samsung.com (KnoxPortal) with ESMTPA id 20260810091332eusmtip28966b93d0c29582d58567c792b4bd9ba~KZshKoKkG2582625826eusmtip2O; Mon, 10 Aug 2026 09:13:32 +0000 (GMT) Message-ID: <7d22482f-d5fd-4cf4-9d32-6a54e02f2fbb@samsung.com> Date: Mon, 10 Aug 2026 11:13:32 +0200 MIME-Version: 1.0 User-Agent: Betterbird (Windows) Subject: Re: [PATCH] arm64: swiotlb: Keep the default size for protected guests To: Jason Gunthorpe , Mostafa Saleh Cc: Will Deacon , "Aneesh Kumar K.V" , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, Robin Murphy , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , 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 , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20260807182017.GH200537@ziepe.ca> Content-Transfer-Encoding: 7bit X-CMS-MailID: 20260810091334eucas1p1e0ed221ce5794cf7bd02a4bed868a380 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20260807182023eucas1p1f653436207b2b00338e99ea1d8f847df X-EPHeader: CA X-CMS-RootMailID: 20260807182023eucas1p1f653436207b2b00338e99ea1d8f847df References: <20260717180442.110954-18-aneesh.kumar@kernel.org> <20260807092612.2202005-1-aneesh.kumar@kernel.org> <20260807135810.GA200537@ziepe.ca> <20260807164734.GE200537@ziepe.ca> <20260807182017.GH200537@ziepe.ca> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260810_021338_811083_3A01A206 X-CRM114-Status: GOOD ( 15.22 ) 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 On 07.08.2026 20:20, Jason Gunthorpe wrote: > On Fri, Aug 07, 2026 at 06:13:49PM +0000, Mostafa Saleh wrote: >> But the whole thing is best effort anyway, the kernel picks >> IO_TLB_DEFAULT_SIZE which does not depend on the system topology or >> how many devices or how much DMA they do. >> SWIOTLB memory is wasted if unused so we should be careful around >> that as it would be the other way around and users would have to >> decrease it manually. > Yeah, it is why the arch code shouldn't really be sizing it directly, > it should be done in common code and, yes, we are probably going to > have to do something alot smarter to have the common code better > auto-tune this for the CC case.. What about the $subject patch? I assume that it is still needed to restore the behavior that was altered by the "[PATCH v8 00/23] dma-mapping: Track shared DMA state through direct, pool and swiotlb paths?" patchset? Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland