From patchwork Wed Aug 21 15:00:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11107261 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 1BDEF1399 for ; Wed, 21 Aug 2019 15:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E475322DD3 for ; Wed, 21 Aug 2019 15:00:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tkfoMKNl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729696AbfHUPAq (ORCPT ); Wed, 21 Aug 2019 11:00:46 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:33271 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728437AbfHUPAp (ORCPT ); Wed, 21 Aug 2019 11:00:45 -0400 Received: by mail-pl1-f195.google.com with SMTP id go14so1483077plb.0; Wed, 21 Aug 2019 08:00:45 -0700 (PDT) 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=R9EIePxtKgh7rutMNGBvqWvR/nyIQIv1yBQVlI6lc80=; b=tkfoMKNl6R00u1CGr4goVFrz53AHxoV7hFxDcGeUp0tOZUCo+74t/zt8j+2QopIgxI EZ3M3c24Jl9SrsJM+dTZwK8SGp7tO2O/0yx89/oESAn4+Y33U06VmjCAJUF8WYGRwZeO eKjbkMOiSUf3GOoqrhSS+vgoRMpgqZeesnV5hVjONU4VcpdOzOxTu/6+rYJJelofQ2l3 KrIWCI8aXlUCizR5/hSFEMJ0SFD0wRsscqpCzcEa6q+HWASFrKQeuvC0VTIT8+HbR6/e kIbuzlNFr7cnr7aQG0JZ89EPMqXTXef7jzZr4LRARx074pduHcDo0oZ2TTBh+XMIA1it tJhw== 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=R9EIePxtKgh7rutMNGBvqWvR/nyIQIv1yBQVlI6lc80=; b=N8uG4VLyAj2C8zZPu4NrH8iGwhXcdjEiiN5HJmGYr+sm3PFBf/Pyzwt7HlAussmJX5 uuh2KCr/NVRpy/FCOi4MwQd/OjeyaG2OR1Prv6rNAAk3VCQa6B55H+LD3STNIPCi1otN ykB7gkK/YLqjz7ob2TZDlZU7vWNgQR9d+qUHujcnJSQdsgcvcGVQE5NLZ6+8G+Hka4+R NgWg86abCUhMb7jJ8pmBCKhxdY64hKNz8X7+E7iSTRQOeM4rCZ5ba3X0eyJNxES/XU/R +KrTvGKM/ZyRferwN3DMFc7JTQDKpqGCiY8HFxFU1wHvGGA1xuJUvu+W0FfDi0C/UOfc 68hA== X-Gm-Message-State: APjAAAXVraNnOmuk8yYcq4qFXu8idC4wI7b7ymwx4ZYuxqXc9CKUqeu1 1PajkZFJpfKCBbJiJUsRzaHgqvXN X-Google-Smtp-Source: APXvYqzGZGBxE2Kux8cFfIoXPTej4Y3Rq0bhdauQWIpL/YOuwEUcP9xBJA0wE9MgWkUpeYVOa9xJ2g== X-Received: by 2002:a17:902:6843:: with SMTP id f3mr31726895pln.97.1566399645002; Wed, 21 Aug 2019 08:00:45 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id b19sm14248033pgs.10.2019.08.21.08.00.44 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Aug 2019 08:00:44 -0700 (PDT) Subject: [PATCH v6 QEMU 3/3] virtio-balloon: Provide a interface for unused page reporting From: Alexander Duyck To: nitesh@redhat.com, kvm@vger.kernel.org, mst@redhat.com, david@redhat.com, dave.hansen@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, virtio-dev@lists.oasis-open.org Cc: yang.zhang.wz@gmail.com, pagupta@redhat.com, riel@surriel.com, konrad.wilk@oracle.com, willy@infradead.org, lcapitulino@redhat.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, mhocko@kernel.org, alexander.h.duyck@linux.intel.com, osalvador@suse.de Date: Wed, 21 Aug 2019 08:00:43 -0700 Message-ID: <20190821150043.21485.84756.stgit@localhost.localdomain> In-Reply-To: <20190821145806.20926.22448.stgit@localhost.localdomain> References: <20190821145806.20926.22448.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 "unused 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 003b3ebcfdfb..7a30df63bc77 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -320,6 +320,40 @@ 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); @@ -627,7 +661,8 @@ 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); @@ -715,7 +750,8 @@ 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); } @@ -805,6 +841,10 @@ 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, @@ -931,6 +971,8 @@ 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;