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 655ADC07E9D for ; Tue, 27 Sep 2022 18:21:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231143AbiI0SVQ (ORCPT ); Tue, 27 Sep 2022 14:21:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231804AbiI0SVL (ORCPT ); Tue, 27 Sep 2022 14:21:11 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51903F5097 for ; Tue, 27 Sep 2022 11:21:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664302866; 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=QY/wexCISEH5Yn9ulasiSSxdGASp9NhnFDcBt09AGSE=; b=FSiWTXLyBKR4+rHrpsZ6BEgnS7Clas3WxECMiVgnbL02lCbvKbGRHXhTx3aojQY6hrkT4u s6zU+IS8qD9gAuYpAywrMoFGbNxaHMivkthzdKB88CycgQpmwBkFUqs9an/3WyDzm9oKl0 dIzz1dLTu928NRsmt+NM9WdbSJLUn98= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-171-bjd58P5UPnew1IbPYs0Jqw-1; Tue, 27 Sep 2022 14:21:05 -0400 X-MC-Unique: bjd58P5UPnew1IbPYs0Jqw-1 Received: by mail-qt1-f197.google.com with SMTP id fx6-20020a05622a4ac600b0035a70ba1cbcso7430900qtb.21 for ; Tue, 27 Sep 2022 11:21:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=QY/wexCISEH5Yn9ulasiSSxdGASp9NhnFDcBt09AGSE=; b=op0bcsLMSfctpSa/O1KtjppybJrxcVwnPBxJfgr3Cysj5P+dq84Ej8V3ewQ2KlTTYA TfQgAdILwohbj+s8zflkffvmrbv524HvZNQVZTzNLHkodjBmIZS0o2m/LAXGzb2GqJ4Q 9qEmTzvc1c0OEny1ihVyWkv6aiZOzmxP+FEZbJWSJk0wxkvaaA//yrTFih80MO8AJmX6 VISPTWUmVJtKHErZj/ir/eoEUxCV6StA4/aMKsSR3rcsjeripEvPRroAGQnxKCIJFBeI PwenWIPOHfl8w65FpZAipJdI8sDWb9wdmf5jjqqIzEhC9K6sZRzN2PSpgx56WFdjJrWc +log== X-Gm-Message-State: ACrzQf14+a7lY2gZ/HexFdQH5nkGm/zg/cRWK9497Un/P9IXP+MS9FWu oJWa0oESyEW14SeoYjupmvdhFRRI4EPDgGiAEUqKUEyU37roFE3rZIGyNK+H1skY5S5wMw8mUCQ ir0EvhMhMB8zv X-Received: by 2002:a05:620a:1929:b0:6ce:f8b0:6de0 with SMTP id bj41-20020a05620a192900b006cef8b06de0mr19149808qkb.489.1664302864488; Tue, 27 Sep 2022 11:21:04 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6tmXzpi6e6VsMU3bm+k4T40OUsVM/7nTV5fmstSLxyFluQ1CU5YAxtcJF6kpYrDafr4b9odw== X-Received: by 2002:a05:620a:1929:b0:6ce:f8b0:6de0 with SMTP id bj41-20020a05620a192900b006cef8b06de0mr19149790qkb.489.1664302864293; Tue, 27 Sep 2022 11:21:04 -0700 (PDT) Received: from x1n (bras-base-aurron9127w-grc-46-70-31-27-79.dsl.bell.ca. [70.31.27.79]) by smtp.gmail.com with ESMTPSA id a2-20020ac81082000000b0035d1f846b91sm1214262qtj.64.2022.09.27.11.21.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Sep 2022 11:21:03 -0700 (PDT) Date: Tue, 27 Sep 2022 14:21:00 -0400 From: Peter Xu To: Marc Zyngier Cc: Gavin Shan , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, catalin.marinas@arm.com, bgardon@google.com, shuah@kernel.org, andrew.jones@linux.dev, will@kernel.org, dmatlack@google.com, pbonzini@redhat.com, zhenyzha@redhat.com, shan.gavin@gmail.com, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, oliver.upton@linux.dev Subject: Re: [PATCH v4 3/6] KVM: arm64: Enable ring-based dirty memory tracking Message-ID: References: <20220927005439.21130-1-gshan@redhat.com> <20220927005439.21130-4-gshan@redhat.com> <86sfkc7mg8.wl-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <86sfkc7mg8.wl-maz@kernel.org> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Sep 27, 2022 at 01:32:07PM -0400, Marc Zyngier wrote: > On Tue, 27 Sep 2022 12:02:52 -0400, > Peter Xu wrote: > > > > On Tue, Sep 27, 2022 at 08:54:36AM +0800, Gavin Shan wrote: > > > Enable ring-based dirty memory tracking on arm64 by selecting > > > CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL and providing the ring buffer's > > > physical page offset (KVM_DIRTY_LOG_PAGE_OFFSET). > > > > > > Signed-off-by: Gavin Shan > > > > Gavin, > > > > Any decision made on how to tackle with the GIC status dirty bits? > > Which dirty bits? Are you talking of the per-RD pending bits? Gavin found that some dirty pfn path may not have vcpu context for aarch64 offlist. Borrowing Gavin's trace dump: el0t_64_sync el0t_64_sync_handler el0_svc do_el0_svc __arm64_sys_ioctl kvm_device_ioctl vgic_its_set_attr vgic_its_save_tables_v0 kvm_write_guest __kvm_write_guest_page mark_page_dirty_in_slot With current code it'll trigger the warning in mark_page_dirty_in_slot. An userspace approach is doable by setting these pages as always dirty in userspace (QEMU), but even if so IIUC we'll need to drop the warning message in mark_page_dirty_in_slot() then we take no-vcpu dirty as no-op and expected. I'll leave the details to Gavin. Thanks, -- Peter Xu