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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75989C433F5 for ; Tue, 22 Feb 2022 08:05:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229458AbiBVIGN (ORCPT ); Tue, 22 Feb 2022 03:06:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiBVIGM (ORCPT ); Tue, 22 Feb 2022 03:06:12 -0500 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 542D9148929; Tue, 22 Feb 2022 00:05:48 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id B968768AA6; Tue, 22 Feb 2022 09:05:43 +0100 (CET) Date: Tue, 22 Feb 2022 09:05:43 +0100 From: Christoph Hellwig To: Tianyu Lan Cc: Christoph Hellwig , kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, hch@infradead.org, m.szyprowski@samsung.com, robin.murphy@arm.com, michael.h.kelley@microsoft.com, Tianyu Lan , iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, vkuznets@redhat.com, brijesh.singh@amd.com, konrad.wilk@oracle.com, parri.andrea@gmail.com, thomas.lendacky@amd.com Subject: Re: [PATCH V2 1/2] Swiotlb: Add swiotlb_alloc_from_low_pages switch Message-ID: <20220222080543.GA5412@lst.de> References: <20220209122302.213882-1-ltykernel@gmail.com> <20220209122302.213882-2-ltykernel@gmail.com> <20220214081919.GA18337@lst.de> <4f433f07-05be-f81f-43e8-55c3f1af23b3@gmail.com> <20220214135834.GA30150@lst.de> <8d052867-ccff-f00f-7c89-cc26a4bfa347@gmail.com> <23f4a64d-5977-1816-8faa-fe7691ace2ff@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <23f4a64d-5977-1816-8faa-fe7691ace2ff@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Mon, Feb 21, 2022 at 11:14:58PM +0800, Tianyu Lan wrote: > Sorry. The boot failure is not related with these patches and the issue > has been fixed in the latest upstream code. > > There is a performance bottleneck due to io tlb mem's spin lock during > performance test. All devices'io queues uses same io tlb mem entry > and the spin lock of io tlb mem introduce overheads. There is a fix patch > from Andi Kleen in the github. Could you have a look? > > https://github.com/intel/tdx/commit/4529b5784c141782c72ec9bd9a92df2b68cb7d45 Please post these things to the list. But I suspect the right answer for the "secure" hypervisor case is to use the per-device swiotlb regions that we've recently added.