From patchwork Tue Feb 11 22:51:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11377073 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4475813A4 for ; Tue, 11 Feb 2020 22:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 197A52082F for ; Tue, 11 Feb 2020 22:51:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RWg0DHYs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727811AbgBKWvp (ORCPT ); Tue, 11 Feb 2020 17:51:45 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:37048 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727646AbgBKWvp (ORCPT ); Tue, 11 Feb 2020 17:51:45 -0500 Received: by mail-wr1-f66.google.com with SMTP id w15so14627155wru.4; Tue, 11 Feb 2020 14:51:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=gbRBokZUeADxG1Js0n3CcSXLvNNKI4dY2r2GfqE2RsE=; b=RWg0DHYshDumqM8KMtdD8WzZEBRBdtcqeptU7cfM++emlBM0larEOBvFM99t8D9+IF f+yjlO17jmr2gdU6vRzDtyc6jwPXblwrne+kIvat6vJnJIGf9MR51g2wmcuMUTcI+8uY oPy/m7ue6+e0HA7536dalkZxz/vAaSTsyrOY7xBgdR6VokqoBmxGaBIt2yCOg+5kkzrl GxdidR52st8cameycVetD0lo8nHhVmMrHBklSFA1l/bBTEBqSzDngjidW1S0TngyWLgS XqMi9DzkafK93/r9NhbP7IhbmwGuE6fUM3t5jdOepH9eqfHCf8CnmJ4/DKYeGxesaCtu 4WOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=gbRBokZUeADxG1Js0n3CcSXLvNNKI4dY2r2GfqE2RsE=; b=gAh/YIkN8eHEF+s3sNXVEDXJcsigFiytW7fHKritA+SCphTZ2okOHkPIsg6f9Nnf9B 8fIs45EFC97OSxheh/uFmT4GlRGyqqcD3iwQay/WisWToqJoJd5xOxp3/upIagTbFkUL QK3Jjo/YNpbTXEsfkYrL4sOg0Oo86Dk+Dgh1DS6lhW+ng8xyGPQOHPrFHEyF/26PQE3W skzHDFubZIX53kC5MayVI8n8C8iYeHsz4et182QuwsHixpCRiaI0hY9WckZmqE/fcakC mAZj8JF7R4sPe3PBYD4tt5hlmb6mdwLpJVDtlg9Ve8KFTw1TToG+bH4omHn7fZ126xM7 100g== X-Gm-Message-State: APjAAAXOPMIvkpaa1NJgv40RD6iInNP/HIWrKLFTg+vJ35F1muQOK7Vf Mz+ziTG4cDbIIODXIvjNd8I= X-Google-Smtp-Source: APXvYqzkuhT8IIjfBmSkf1LMLzuqn/V5z54dpY3u54czC6sPEmwWmluvmOO2tESqZZOptp3wLYYUJQ== X-Received: by 2002:adf:9c8d:: with SMTP id d13mr11670626wre.392.1581461502576; Tue, 11 Feb 2020 14:51:42 -0800 (PST) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id d204sm5547055wmd.30.2020.02.11.14.51.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Feb 2020 14:51:42 -0800 (PST) Subject: [PATCH v17 QEMU 3/3] virtio-balloon: Provide a interface for free page reporting From: Alexander Duyck To: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, mst@redhat.com, david@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Cc: yang.zhang.wz@gmail.com, pagupta@redhat.com, konrad.wilk@oracle.com, nitesh@redhat.com, riel@surriel.com, willy@infradead.org, lcapitulino@redhat.com, dave.hansen@intel.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, mhocko@kernel.org, mgorman@techsingularity.net, alexander.h.duyck@linux.intel.com, vbabka@suse.cz, osalvador@suse.de Date: Tue, 11 Feb 2020 14:51:36 -0800 Message-ID: <20200211225136.30409.19938.stgit@localhost.localdomain> In-Reply-To: <20200211224416.29318.44077.stgit@localhost.localdomain> References: <20200211224416.29318.44077.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Alexander Duyck Add support for what I am referring to as "free page reporting". Basically the idea is to function very similar to how the balloon works in that we basically end up madvising the page as not being used. However we don't really need to bother with any deflate type logic since the page will be faulted back into the guest when it is read or written to. This is meant to be a simplification of the existing balloon interface to use for providing hints to what memory needs to be freed. I am assuming this is safe to do as the deflate logic does not actually appear to do very much other than tracking what subpages have been released and which ones haven't. Signed-off-by: Alexander Duyck --- hw/virtio/virtio-balloon.c | 46 ++++++++++++++++++++++++++++++++++-- include/hw/virtio/virtio-balloon.h | 2 +- 2 files changed, 45 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 455d85b7082f..5faafd2f62ac 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -321,6 +321,40 @@ static void balloon_stats_set_poll_interval(Object *obj, Visitor *v, balloon_stats_change_timer(s, 0); } +static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq) +{ + VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); + VirtQueueElement *elem; + + while ((elem = virtqueue_pop(vq, sizeof(VirtQueueElement)))) { + unsigned int i; + + for (i = 0; i < elem->in_num; i++) { + void *addr = elem->in_sg[i].iov_base; + size_t size = elem->in_sg[i].iov_len; + ram_addr_t ram_offset; + size_t rb_page_size; + RAMBlock *rb; + + if (qemu_balloon_is_inhibited() || dev->poison_val) + continue; + + rb = qemu_ram_block_from_host(addr, false, &ram_offset); + rb_page_size = qemu_ram_pagesize(rb); + + /* For now we will simply ignore unaligned memory regions */ + if ((ram_offset | size) & (rb_page_size - 1)) + continue; + + ram_block_discard_range(rb, ram_offset, size); + } + + virtqueue_push(vq, elem, 0); + virtio_notify(vdev, vq); + g_free(elem); + } +} + static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBalloon *s = VIRTIO_BALLOON(vdev); @@ -628,7 +662,8 @@ static size_t virtio_balloon_config_size(VirtIOBalloon *s) return sizeof(struct virtio_balloon_config); } if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON) || - virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { + virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT) || + virtio_has_feature(features, VIRTIO_BALLOON_F_REPORTING)) { return sizeof(struct virtio_balloon_config); } return offsetof(struct virtio_balloon_config, free_page_report_cmd_id); @@ -716,7 +751,8 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f, VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); f |= dev->host_features; virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ); - if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { + if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT) || + virtio_has_feature(f, VIRTIO_BALLOON_F_REPORTING)) { virtio_add_feature(&f, VIRTIO_BALLOON_F_PAGE_POISON); } @@ -806,6 +842,10 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats); + if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) { + s->rvq = virtio_add_queue(vdev, 32, virtio_balloon_handle_report); + } + if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE, @@ -939,6 +979,8 @@ static Property virtio_balloon_properties[] = { */ DEFINE_PROP_BOOL("qemu-4-0-config-size", VirtIOBalloon, qemu_4_0_config_size, false), + DEFINE_PROP_BIT("unused-page-reporting", VirtIOBalloon, host_features, + VIRTIO_BALLOON_F_REPORTING, true), DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD, IOThread *), DEFINE_PROP_END_OF_LIST(), diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h index 7fe78e5c14d7..db5bf7127112 100644 --- a/include/hw/virtio/virtio-balloon.h +++ b/include/hw/virtio/virtio-balloon.h @@ -42,7 +42,7 @@ enum virtio_balloon_free_page_report_status { typedef struct VirtIOBalloon { VirtIODevice parent_obj; - VirtQueue *ivq, *dvq, *svq, *free_page_vq; + VirtQueue *ivq, *dvq, *svq, *free_page_vq, *rvq; uint32_t free_page_report_status; uint32_t num_pages; uint32_t actual;