From patchwork Fri Jan 3 21:21:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11317459 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 0305F1395 for ; Fri, 3 Jan 2020 21:21:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBBBC206DB for ; Fri, 3 Jan 2020 21:21:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fgD2WG3T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728826AbgACVVX (ORCPT ); Fri, 3 Jan 2020 16:21:23 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:35243 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728722AbgACVVX (ORCPT ); Fri, 3 Jan 2020 16:21:23 -0500 Received: by mail-pf1-f195.google.com with SMTP id i23so18625240pfo.2; Fri, 03 Jan 2020 13:21:22 -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=k/7N+WeIMLf1qaqKurny6a/721nmeSdfaWITRnU52O8=; b=fgD2WG3TALiBHmWa/NBkwqNO6YFTOB6RXKGmmWKBUKdNgmIThmkPiI+bj2BM+fNBsd 93bEQEQT1nH2hfNr3OMqr1zXq7fYVINLZbtuYfLm2EgCqw+s61lZqaYhivXGbfklXqqc GG/yyeCO6FeQpP/8byirqQ3MHETYofPljjxMdglG1m5JFmfFP2tnDIpYYNdLAqmwdfD2 rX8c9AMOdL1bYseVhwLI08K03iK960LlMvL6Vvyz/9tepIuXwr6mAgyTQUUNeFpPZx0s +FzuTOIqFaDCTNUb6jOmj8w8V0e26P1/MYuY5kRit3qhmE4yWid2AxUhNIvTgDCVQf2a 9sSA== 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=k/7N+WeIMLf1qaqKurny6a/721nmeSdfaWITRnU52O8=; b=jvuhvBRd0ZXkAtbZkj47K0Vxu8Ftgb/43+cC7YMTNQbi4sBNo7R0c5ilHCYACbCAYD Y0lNaNOfw4FPXiVOupt8Mns29SBaPDW0aav4tN3hWPgwL6PDGFq0aWxrgwc+pZrNDgdh YYD3BHTySUzSho13YzZWKywNQhRWcYRdThZZjN+HQMxqOjXniiIfgcrUACL+8NT2/sp2 0/DCbyCLcSJJeaJhrfG6N2dkYF5nZG2Hfdzm+MZP7K+7YDW2vibQPuV2UPsHn0YoXot1 j6PWPQzIOSbxLjb2VXFVrmdwax65Xo4x4sncsIG/ELnbDSC4vgRw8UgbQWeY0UWaVl3Y XvsA== X-Gm-Message-State: APjAAAXc36cokR5/5rcP/oUdaRWmmqWI3VexNEi28PrbyUgAuXuebjAM +T+0sBwIWhH8CFQbT2AtdBg= X-Google-Smtp-Source: APXvYqx12Ey0NunsKUZzmZ5aRdGnjpdEnYE9dsNE3MlNVxBfzNG2Yzs+Q/CUPkU6941tThRo91CYoA== X-Received: by 2002:a63:7944:: with SMTP id u65mr84122620pgc.298.1578086481966; Fri, 03 Jan 2020 13:21:21 -0800 (PST) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id f81sm69930500pfa.118.2020.01.03.13.21.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 Jan 2020 13:21:21 -0800 (PST) Subject: [PATCH v16 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, 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: Fri, 03 Jan 2020 13:21:20 -0800 Message-ID: <20200103212120.29681.4564.stgit@localhost.localdomain> In-Reply-To: <20200103210509.29237.18426.stgit@localhost.localdomain> References: <20200103210509.29237.18426.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 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;