From patchwork Fri Sep 6 14:54:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11135497 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 7EAF61395 for ; Fri, 6 Sep 2019 14:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57B25214DE for ; Fri, 6 Sep 2019 14:54:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K7Hb+8Hh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405670AbfIFOyv (ORCPT ); Fri, 6 Sep 2019 10:54:51 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:45554 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394700AbfIFOyv (ORCPT ); Fri, 6 Sep 2019 10:54:51 -0400 Received: by mail-pf1-f194.google.com with SMTP id y72so4626481pfb.12; Fri, 06 Sep 2019 07:54:50 -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=K7Hb+8Hh6OGFNptrd3xhs0dSBGL89ydD/TEtpjhiu9tPxvrsGW3oZrKONgKiu45x/P dAbz7znolXERw89jByTZcAJWibJCzG0jedqFEGgpoJoUBO8qpsB7BBgraJiTg8Ry2NjA cFWicLV2bexuIOGZulOA00dHHT+tzHPWjOnL3X8puT4y/bCgbfvETE/JpOryD+JF7qb6 f4DJmu/f0YRPuc0T7TkL7ScmlDt8nGyn0uxI7SXUFtPtXo01hwiAi1PxcFeYZTMEZcxU nse6Vg4Q57o1ncXt/v2IDpjPPRvRkrAZoEnIkkaUX6KReSNrAhmG/BdcGcpJCeov5gII nPDQ== 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=oPlorYZOg+/dMDI2y8KWunxDTdl3FJdc/9qzOZYBDxhR9PHxTT/jvTB6CS6NRnW+cC heRVfzBIhAHC12LynP9LYqfAMiNUD9qj34hquQuh5b+YXVeCntT/5SIedvinnOU4hCB0 Nd00XoV+iyYvavyxXQidZxKt/DzOMW4m5CFNIInwFMDoeG1bsbdlyrkh/VfRw+eFtFXn xCTHt+Y3Gs2TsOa0yaxzYCjzUUa8TDYVTQISkFv9hjj/9RVeF3QwEO0+066+Gb58VTKa XY/5az66XMrM1+nw+flMmaHhvs3Q11f4sbNINKXbEu1M8BbQRoPRyS7s9Teh4DDcNfhO /MLw== X-Gm-Message-State: APjAAAWrTR/+lLDpW7Vsqt6/pngP1biaCgW0Ygc1uv9QxYnXaAvO0cQe 2VsR8ZZUlGgUd78Z3b2Q7Cc= X-Google-Smtp-Source: APXvYqyR/D4tsD7rhNX2PQcMu+Gyd4kcgZa1BS+hYcFptabaRpV4hgMyTPouaYkRi3vtvC8wwpCvOQ== X-Received: by 2002:a17:90a:c20c:: with SMTP id e12mr10459302pjt.14.1567781690374; Fri, 06 Sep 2019 07:54:50 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id v7sm3096573pjr.29.2019.09.06.07.54.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Sep 2019 07:54:49 -0700 (PDT) Subject: [PATCH v8 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: Fri, 06 Sep 2019 07:54:49 -0700 Message-ID: <20190906145449.574.85741.stgit@localhost.localdomain> In-Reply-To: <20190906145213.32552.30160.stgit@localhost.localdomain> References: <20190906145213.32552.30160.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;