From patchwork Thu Dec 5 16:24:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11275191 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 4D4A113A4 for ; Thu, 5 Dec 2019 16:24:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E3572464D for ; Thu, 5 Dec 2019 16:24:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rZy8V/vY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730106AbfLEQYh (ORCPT ); Thu, 5 Dec 2019 11:24:37 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:36654 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730025AbfLEQYf (ORCPT ); Thu, 5 Dec 2019 11:24:35 -0500 Received: by mail-qt1-f195.google.com with SMTP id k11so4080933qtm.3; Thu, 05 Dec 2019 08:24:34 -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=IYnIZF3ya8GRMyw0Z8v44wRFjachYcZ/Qaw0Oz7Yqys=; b=rZy8V/vYjGvdbgJlSFDtmo8ogCsBeJGr6yuSCLQteDkgYJTOlDnBamwOQxlrK2xI3Z EoqHXHkvYA5Rzl8VAkLsvudDATzeFfXjQK4e+rRSVN8xUoBXBxS1xlzH0lWDP1DdM+mC +v5Zkh5NMc1XHazTbBnfZIQSpjiC129hvAyrRhiLSSpKg/pyMTiZVoteLjnYb1Sy5LG7 tTRhQ7OIWfag0kwcI2RCK2UVftjRGuaLUIATqtm97TbEQ7JvLl6fS4qmQKeIVt5mKBtr SfWzRbSkTLAsLHjLFn8IWi7YYje8A4y2fygga4aBsVmNy9zlMJFttmKhMf8KPoksWYL/ duTg== 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=DOnCwxzwwp/wF8uNmifg3j0T3VfnBNYVA7wQc1TkRuYa5pGRXjWfUww13Gfjex8H2c WzW5xpUEGXQBnrfgSiAyFGP4nC4HvY+a5YUmevdX1IK0icYabfDUdS+q4TeessnXzOv/ bi2NCuO6V3yh1aG2seNM9+TX9bNCtyS6TG9nDay2VNjM9CxNoFJZeMQwf/a0VKznUnKc QvvgnqafqyKRa2QoRxhGCxJ9ThjuVFuPxKc+WFHkBQA/dblCpPZQ1vQjwvPAArRWvkKa OpqdkkiyFn+fnzAgXdnvHYntoTHTYYFQfIWcaqhC4Pg2+9qiBUrclj/fgTrsS2AXPLH+ x5XA== X-Gm-Message-State: APjAAAUy8sBsEJkRN/DlIHD1MSA6iTPH4cRhQRQFOxo8wYWCxh+UJmJ1 UEr89++v82Q1Zbplx7oBaik= X-Google-Smtp-Source: APXvYqyHkpEt+nyTFEI72kz7jPPyhHyR1sq3FFWTrrVMlKqbT1JWZmRDdTHVkJmw4SOSMOkOJJlhSw== X-Received: by 2002:aed:3344:: with SMTP id u62mr8242458qtd.73.1575563074222; Thu, 05 Dec 2019 08:24:34 -0800 (PST) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id w40sm5442163qtw.26.2019.12.05.08.24.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Dec 2019 08:24:33 -0800 (PST) Subject: [PATCH v15 QEMU 3/3] virtio-balloon: Provide a interface for unused 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: Thu, 05 Dec 2019 08:24:30 -0800 Message-ID: <20191205162430.19737.266.stgit@localhost.localdomain> In-Reply-To: <20191205161928.19548.41654.stgit@localhost.localdomain> References: <20191205161928.19548.41654.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;