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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7539BC10DCE for ; Thu, 12 Mar 2020 08:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 39ED6206EB for ; Thu, 12 Mar 2020 08:25:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GPNOC3KZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726539AbgCLIZW (ORCPT ); Thu, 12 Mar 2020 04:25:22 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:43209 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725980AbgCLIZV (ORCPT ); Thu, 12 Mar 2020 04:25:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584001520; 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=UqiBqBozQZrKbpqb6fps1Ub+53xZKmdnmK5P35tZZ6M=; b=GPNOC3KZYX+dQA+xo+kQ3kVzVJRcmjBGJVvjOXTwJkwzbwbENM1uEqDQCIPlC3OYdz5D4X d0QpjIrHkj2zJaRlDfKvlIk0AJXlN88e6EhbCo4VOkaJp9u81Vqxzp/9KaPDCfaJx/XCTh tWKg6T3HGBPMyhWIv4RS5rkD0o1ZjBY= Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-309-sQ-8U3lqMDe8_rckyUSW5g-1; Thu, 12 Mar 2020 04:25:15 -0400 X-MC-Unique: sQ-8U3lqMDe8_rckyUSW5g-1 Received: by mail-qt1-f199.google.com with SMTP id k20so2967764qtm.11 for ; Thu, 12 Mar 2020 01:25:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=UqiBqBozQZrKbpqb6fps1Ub+53xZKmdnmK5P35tZZ6M=; b=TYzNiMCjCirMY/xgGCZmvMRNX85mr2K0hIQkuYJ1qfQeD7u9cETw0jVrriYVG1s6ua uQwTGgdW0cmG4+N+6elA3rMNuJqXYT4EfFcjROsT3h1BWMm0AAqNJKdQNeJENFRmO77v Gqzhon/ZgWO0PbFmpsVPJ10LAKwkUFvsE2acC/KtKIZBMyiC1y8mVHQwVd++qSSJBSKe NQmjDe6OJz4/8AD1i+KPrqKTy7vstymsNZq7BNZOK2o+72qPFAYcFCcvL2HZ2Ho9ObBl SbDYtfHf7/B7tBm8tdGmwatH3iLZk31Q62M23HN5iGP+f8aiV+fyNxN86oT0uBynB7FT 67Ng== X-Gm-Message-State: ANhLgQ0NVN45pPo+BMWBY8uiQdDs4mLo0jjr/OAK6yjhYgI72qMr3nr/ 71KxDwsMnOcBiZyXYlu99ST0MLXNSuBRc13a2D0nKURMTsay0PvxNRmZ95YXFfvMQ7HwFL4JN6i l5kfTuwiHK5smfm/ASJNQjFXW X-Received: by 2002:a37:6215:: with SMTP id w21mr6548595qkb.149.1584001514432; Thu, 12 Mar 2020 01:25:14 -0700 (PDT) X-Google-Smtp-Source: ADFU+vunTOq0UJjwugXSegnRqEyiS9dlQvVqcZDLsJQHR9PIHKEvp8WKkpEby0VCBTZybNkeotxyBA== X-Received: by 2002:a37:6215:: with SMTP id w21mr6548575qkb.149.1584001514073; Thu, 12 Mar 2020 01:25:14 -0700 (PDT) Received: from redhat.com (bzq-79-178-2-19.red.bezeqint.net. [79.178.2.19]) by smtp.gmail.com with ESMTPSA id 82sm10496917qkd.62.2020.03.12.01.25.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2020 01:25:13 -0700 (PDT) Date: Thu, 12 Mar 2020 04:25:07 -0400 From: "Michael S. Tsirkin" To: Hui Zhu Cc: jasowang@redhat.com, akpm@linux-foundation.org, pagupta@redhat.com, mojha@codeaurora.org, david@redhat.com, namit@vmware.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Hui Zhu Subject: Re: [RFC for QEMU] virtio-balloon: Add option thp-order to set VIRTIO_BALLOON_F_THP_ORDER Message-ID: <20200312042340-mutt-send-email-mst@kernel.org> References: <1583999395-9131-1-git-send-email-teawater@gmail.com> <1583999395-9131-2-git-send-email-teawater@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1583999395-9131-2-git-send-email-teawater@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 03:49:55PM +0800, Hui Zhu wrote: > If the guest kernel has many fragmentation pages, use virtio_balloon > will split THP of QEMU when it calls MADV_DONTNEED madvise to release > the balloon pages. > Set option thp-order to on will open flags VIRTIO_BALLOON_F_THP_ORDER. > It will set balloon size to THP size to handle the THP split issue. > > Signed-off-by: Hui Zhu What's wrong with just using the PartiallyBalloonedPage machinery instead? That would make it guest transparent. > --- > hw/virtio/virtio-balloon.c | 67 ++++++++++++++++--------- > include/standard-headers/linux/virtio_balloon.h | 4 ++ > 2 files changed, 47 insertions(+), 24 deletions(-) > > diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c > index a4729f7..cfe86b0 100644 > --- a/hw/virtio/virtio-balloon.c > +++ b/hw/virtio/virtio-balloon.c > @@ -340,37 +340,49 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) > while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) { > unsigned int p = virtio_ldl_p(vdev, &pfn); > hwaddr pa; > + size_t handle_size = BALLOON_PAGE_SIZE; > > pa = (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT; > offset += 4; > > - section = memory_region_find(get_system_memory(), pa, > - BALLOON_PAGE_SIZE); > - if (!section.mr) { > - trace_virtio_balloon_bad_addr(pa); > - continue; > - } > - if (!memory_region_is_ram(section.mr) || > - memory_region_is_rom(section.mr) || > - memory_region_is_romd(section.mr)) { > - trace_virtio_balloon_bad_addr(pa); > - memory_region_unref(section.mr); > - continue; > - } > + if (virtio_has_feature(s->host_features, > + VIRTIO_BALLOON_F_THP_ORDER)) > + handle_size = BALLOON_PAGE_SIZE << VIRTIO_BALLOON_THP_ORDER; > + > + while (handle_size > 0) { > + section = memory_region_find(get_system_memory(), pa, > + BALLOON_PAGE_SIZE); > + if (!section.mr) { > + trace_virtio_balloon_bad_addr(pa); > + continue; > + } > + if (!memory_region_is_ram(section.mr) || > + memory_region_is_rom(section.mr) || > + memory_region_is_romd(section.mr)) { > + trace_virtio_balloon_bad_addr(pa); > + memory_region_unref(section.mr); > + continue; > + } > > - trace_virtio_balloon_handle_output(memory_region_name(section.mr), > - pa); > - if (!qemu_balloon_is_inhibited()) { > - if (vq == s->ivq) { > - balloon_inflate_page(s, section.mr, > - section.offset_within_region, &pbp); > - } else if (vq == s->dvq) { > - balloon_deflate_page(s, section.mr, section.offset_within_region); > - } else { > - g_assert_not_reached(); > + trace_virtio_balloon_handle_output(memory_region_name(section.mr), > + pa); > + if (!qemu_balloon_is_inhibited()) { > + if (vq == s->ivq) { > + balloon_inflate_page(s, section.mr, > + section.offset_within_region, > + &pbp); > + } else if (vq == s->dvq) { > + balloon_deflate_page(s, section.mr, > + section.offset_within_region); > + } else { > + g_assert_not_reached(); > + } > } > + memory_region_unref(section.mr); > + > + pa += BALLOON_PAGE_SIZE; > + handle_size -= BALLOON_PAGE_SIZE; > } > - memory_region_unref(section.mr); > } > > virtqueue_push(vq, elem, offset); > @@ -693,6 +705,8 @@ static void virtio_balloon_set_config(VirtIODevice *vdev, > > memcpy(&config, config_data, virtio_balloon_config_size(dev)); > dev->actual = le32_to_cpu(config.actual); > + if (virtio_has_feature(vdev->host_features, VIRTIO_BALLOON_F_THP_ORDER)) > + dev->actual <<= VIRTIO_BALLOON_THP_ORDER; > if (dev->actual != oldactual) { > qapi_event_send_balloon_change(vm_ram_size - > ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT)); > @@ -728,6 +742,9 @@ static void virtio_balloon_to_target(void *opaque, ram_addr_t target) > } > if (target) { > dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; > + if (virtio_has_feature(dev->host_features, > + VIRTIO_BALLOON_F_THP_ORDER)) > + dev->num_pages >>= VIRTIO_BALLOON_THP_ORDER; > virtio_notify_config(vdev); > } > trace_virtio_balloon_to_target(target, dev->num_pages); > @@ -916,6 +933,8 @@ static Property virtio_balloon_properties[] = { > VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false), > DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features, > VIRTIO_BALLOON_F_FREE_PAGE_HINT, false), > + DEFINE_PROP_BIT("thp-order", VirtIOBalloon, host_features, > + VIRTIO_BALLOON_F_THP_ORDER, false), > /* QEMU 4.0 accidentally changed the config size even when free-page-hint > * is disabled, resulting in QEMU 3.1 migration incompatibility. This > * property retains this quirk for QEMU 4.1 machine types. > diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h > index 9375ca2..f54d613 100644 > --- a/include/standard-headers/linux/virtio_balloon.h > +++ b/include/standard-headers/linux/virtio_balloon.h > @@ -36,10 +36,14 @@ > #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ > #define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */ > #define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */ > +#define VIRTIO_BALLOON_F_THP_ORDER 5 /* Set balloon page order to thp order */ > > /* Size of a PFN in the balloon interface. */ > #define VIRTIO_BALLOON_PFN_SHIFT 12 > > +/* The order of the balloon page */ > +#define VIRTIO_BALLOON_THP_ORDER 9 > + > #define VIRTIO_BALLOON_CMD_ID_STOP 0 > #define VIRTIO_BALLOON_CMD_ID_DONE 1 > struct virtio_balloon_config { > -- > 2.7.4