From patchwork Tue Oct 22 22:29:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11205439 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 4013E13BD for ; Tue, 22 Oct 2019 22:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15E8F218AE for ; Tue, 22 Oct 2019 22:29:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iKFrq92y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389371AbfJVW3k (ORCPT ); Tue, 22 Oct 2019 18:29:40 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:46703 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731220AbfJVW3j (ORCPT ); Tue, 22 Oct 2019 18:29:39 -0400 Received: by mail-pg1-f194.google.com with SMTP id e15so10798401pgu.13; Tue, 22 Oct 2019 15:29:39 -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=IYnIZF3ya8GRMyw0Z8v44wRFjachYcZ/Qaw0Oz7Yqys=; b=iKFrq92yC0OttYiOPOr/01Xrnyzk4LoPd7Kcq49VUCN6eCevIwwnzOhDsuG7WKAr8O r/tdirFVwlmIF4XVYxJFp8SMy32fgK5tLn8fTB3UFfxB/f/ERF5gnBU0unC7O+CBNIaG tH/jGGoZpWYS3TUu0CBrAfDgx38RUWQa8YNRUFfb+XQZm2LuLisSnddhJdwMYa+hRLmi FG51Yo0v/rEZdthSazebVEJha9R7TzUojsB7wi/epBbyrsC21X825kMkvtdovDrYcAPU AkTswIZmv7maSnB0W+OsWy0E7hHp/Qc7EHAMeBROhHub00ymWR/lHhP7F1vKpuzss+SG pIVQ== 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=IYnIZF3ya8GRMyw0Z8v44wRFjachYcZ/Qaw0Oz7Yqys=; b=Yjq2JfBU9ZOjMtk/LOExbLGNNFPWL1PgdsGj+kJYRrEB34XcCzWsG8x668/jtvozc7 laZ324v/becppJXKqIIpNTI38MC0yf8Wx1ULiSZ701PyGj6jVg6QHWgxQJ3FiTtnXUlb 8+ubUBZ/idgA8qHVgEXXpYQ6MBLYsOfPhoaB2wdrKZPskwC/tC2KDcoduIjXBZyK06uT LJRNJ6k2BBOocyx06WETzvFamMU+DagtesVMpkmseDHE/wTTp3uCU5vMyHJaWJL9i3Ud 1DmFaH3Fb+czSUYmPgVG3i6MwPLoSh2rvgUukIRKf9jkteeon1cmxSKeL3NeUz87u/v3 pztg== X-Gm-Message-State: APjAAAUIx1kaMpY63hy/1eYGzH7TK8HmmGtkDEGVCVb0oOCaJRq4hASZ pfLltarGuJtgwgvqqqKTEcE= X-Google-Smtp-Source: APXvYqxYOPYId/zCW4hr+ch1HRgSCj3NHWSShCU2POCjbAJhcHE4hlH9edmKaMVP7+uqCPxzCvmVBA== X-Received: by 2002:a65:4bc3:: with SMTP id p3mr6338350pgr.188.1571783378951; Tue, 22 Oct 2019 15:29:38 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id o123sm7482309pfg.161.2019.10.22.15.29.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Oct 2019 15:29:38 -0700 (PDT) Subject: [PATCH v12 QEMU 3/3] virtio-balloon: Provide a interface for unused page reporting From: Alexander Duyck To: kvm@vger.kernel.org, mst@redhat.com, linux-kernel@vger.kernel.org, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, mgorman@techsingularity.net, vbabka@suse.cz Cc: yang.zhang.wz@gmail.com, nitesh@redhat.com, konrad.wilk@oracle.com, david@redhat.com, pagupta@redhat.com, riel@surriel.com, lcapitulino@redhat.com, dave.hansen@intel.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, alexander.h.duyck@linux.intel.com, osalvador@suse.de Date: Tue, 22 Oct 2019 15:29:37 -0700 Message-ID: <20191022222937.17594.71516.stgit@localhost.localdomain> In-Reply-To: <20191022221223.17338.5860.stgit@localhost.localdomain> References: <20191022221223.17338.5860.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 6ecfec422309..47f253d016db 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, @@ -932,6 +972,8 @@ 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;