From patchwork Wed Sep 18 17:53:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11151085 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 1D7C814DB for ; Wed, 18 Sep 2019 17:53:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C23622196E for ; Wed, 18 Sep 2019 17:53:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="e2N1Rvh5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C23622196E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EBFDA6B02E9; Wed, 18 Sep 2019 13:53:17 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E49316B02EA; Wed, 18 Sep 2019 13:53:17 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D37086B02EB; Wed, 18 Sep 2019 13:53:17 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0158.hostedemail.com [216.40.44.158]) by kanga.kvack.org (Postfix) with ESMTP id AFB416B02E9 for ; Wed, 18 Sep 2019 13:53:17 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 48800181AC9B6 for ; Wed, 18 Sep 2019 17:53:17 +0000 (UTC) X-FDA: 75948788034.24.rose87_1ca7754849437 X-Spam-Summary: 2,0,0,ef17e2d8aa19ffa1,d41d8cd98f00b204,alexander.duyck@gmail.com,:virtio-dev@lists.oasis-open.org:kvm@vger.kernel.org:mst@redhat.com:david@redhat.com:dave.hansen@intel.com:linux-kernel@vger.kernel.org:willy@infradead.org:mhocko@kernel.org::vbabka@suse.cz:akpm@linux-foundation.org:mgorman@techsingularity.net:linux-arm-kernel@lists.infradead.org:osalvador@suse.de:yang.zhang.wz@gmail.com:pagupta@redhat.com:konrad.wilk@oracle.com:nitesh@redhat.com:riel@surriel.com:lcapitulino@redhat.com:wei.w.wang@intel.com:aarcange@redhat.com:pbonzini@redhat.com:dan.j.williams@intel.com:alexander.h.duyck@linux.intel.com,RULES_HIT:1:2:41:152:355:379:960:966:968:973:988:989:1260:1277:1311:1313:1314:1345:1359:1431:1437:1515:1516:1518:1593:1594:1605:1730:1747:1777:1792:2196:2198:2199:2200:2393:2559:2562:2693:2918:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:3874:4049:4250:4321:4385:4605:5007:6119:6261:6653:6737:6742:7576:7903:8603:9010:9413:10004:11026:11473:11658:11914:12 043:1204 X-HE-Tag: rose87_1ca7754849437 X-Filterd-Recvd-Size: 10522 Received: from mail-oi1-f194.google.com (mail-oi1-f194.google.com [209.85.167.194]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Wed, 18 Sep 2019 17:53:16 +0000 (UTC) Received: by mail-oi1-f194.google.com with SMTP id i185so329566oif.9 for ; Wed, 18 Sep 2019 10:53:16 -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=mn811CvvWzN3jT4Al3MUAyM7QLy5vWDmmwUaNApsqLI=; b=e2N1Rvh5CnsPgzn73O1X7IG0/k5i/gprW74Cr40N8g8VvkyHwsmD5WZJwQFqTXx+F2 nrdfghedGt/mhBCk01ksi/hGINb8JhKoM/BwZsEDjH7N74lieYdcKc70HfdFdSlqtGmz Bl+qlAoLHAEmR2GjeDIsIfsjyK14P+RAodNh6K5IH31cm97Fc7aoBpS2I76Yi07bWgU8 GAN5l9jgxhwI0QLv1moHEafKVjak+A6AkKdiPgBrMjdbdWAWXuBRG3Ndcoi6/7gm+vZE uAVo9KbW7bN9R10h72Y6KFZnt0TvgdDdFmP9mLHSAVTYJpbFUmzml0trz8f27cvjaCr4 RmrQ== 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=mn811CvvWzN3jT4Al3MUAyM7QLy5vWDmmwUaNApsqLI=; b=n3PBVLNztGezA9DFrBcAvjpSrGuri1nSaR6ehOAKb7oTri5nSHJ9evapmZZgxfI322 qAAXwXs+uGPVQsb8yLITeSjL7gi+h6g8dpTAGNc/cXloLvPzVYCxqByO3i1HJUY0YCwT jbI/IytJQkVm7dnwYLyoJ+7uNUPgVWLnHZ7ou7RxJ8GuQSbbrRsiczBuan8YK0141Y7L 75pABPsJ/fDuJUM8YUPRROJXQKD53wV0NAM38YxFuKofOFwuNCUnA7+wTA6s0gc+F183 KA275oCGMN5ixq6EgiauL1W021Mra90c7INAFmrXFN/hJ+2ElyW2G+Wn+7cQqMA8sQNK inqQ== X-Gm-Message-State: APjAAAWRzynAp+lxMc5Uw5EWCcuI5ZPRfC8dYwYN63ervr4fkxlHPyGr xAbrrwGLcfbHCpzgdaZBKQPLBBzQdD7ctA== X-Google-Smtp-Source: APXvYqx3pqlRwoKEwFCPayUZe5KAwkQRmf4ve3cVECk4baQjoVPyz0JyAqi+dhto/PVdkL4HCzFoLQ== X-Received: by 2002:aca:7509:: with SMTP id q9mr2948237oic.111.1568829195987; Wed, 18 Sep 2019 10:53:15 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id p7sm1952343oif.8.2019.09.18.10.53.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Sep 2019 10:53:15 -0700 (PDT) Subject: [PATCH v10 6/6] virtio-balloon: Add support for providing unused page reports to host From: Alexander Duyck To: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, mst@redhat.com, david@redhat.com, dave.hansen@intel.com, linux-kernel@vger.kernel.org, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, vbabka@suse.cz, akpm@linux-foundation.org, mgorman@techsingularity.net, linux-arm-kernel@lists.infradead.org, osalvador@suse.de Cc: yang.zhang.wz@gmail.com, pagupta@redhat.com, konrad.wilk@oracle.com, nitesh@redhat.com, riel@surriel.com, lcapitulino@redhat.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, alexander.h.duyck@linux.intel.com Date: Wed, 18 Sep 2019 10:53:13 -0700 Message-ID: <20190918175313.23474.89510.stgit@localhost.localdomain> In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain> References: <20190918175109.23474.67039.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alexander Duyck Add support for the page reporting feature provided by virtio-balloon. Reporting differs from the regular balloon functionality in that is is much less durable than a standard memory balloon. Instead of creating a list of pages that cannot be accessed the pages are only inaccessible while they are being indicated to the virtio interface. Once the interface has acknowledged them they are placed back into their respective free lists and are once again accessible by the guest system. Signed-off-by: Alexander Duyck --- drivers/virtio/Kconfig | 1 + drivers/virtio/virtio_balloon.c | 65 +++++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_balloon.h | 1 + 3 files changed, 67 insertions(+) diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 078615cf2afc..4b2dd8259ff5 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -58,6 +58,7 @@ config VIRTIO_BALLOON tristate "Virtio balloon driver" depends on VIRTIO select MEMORY_BALLOON + select PAGE_REPORTING ---help--- This driver supports increasing and decreasing the amount of memory within a KVM guest. diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 501a8d0ebf86..40a6dcaf368f 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -19,6 +19,7 @@ #include #include #include +#include /* * Balloon device works in 4K page units. So each page is pointed to by @@ -37,6 +38,9 @@ #define VIRTIO_BALLOON_FREE_PAGE_SIZE \ (1 << (VIRTIO_BALLOON_FREE_PAGE_ORDER + PAGE_SHIFT)) +/* limit on the number of pages that can be on the reporting vq */ +#define VIRTIO_BALLOON_VRING_HINTS_MAX 16 + #ifdef CONFIG_BALLOON_COMPACTION static struct vfsmount *balloon_mnt; #endif @@ -46,6 +50,7 @@ enum virtio_balloon_vq { VIRTIO_BALLOON_VQ_DEFLATE, VIRTIO_BALLOON_VQ_STATS, VIRTIO_BALLOON_VQ_FREE_PAGE, + VIRTIO_BALLOON_VQ_REPORTING, VIRTIO_BALLOON_VQ_MAX }; @@ -113,6 +118,10 @@ struct virtio_balloon { /* To register a shrinker to shrink memory upon memory pressure */ struct shrinker shrinker; + + /* Unused page reporting device */ + struct virtqueue *reporting_vq; + struct page_reporting_dev_info ph_dev_info; }; static struct virtio_device_id id_table[] = { @@ -152,6 +161,32 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq) } +void virtballoon_unused_page_report(struct page_reporting_dev_info *ph_dev_info, + unsigned int nents) +{ + struct virtio_balloon *vb = + container_of(ph_dev_info, struct virtio_balloon, ph_dev_info); + struct virtqueue *vq = vb->reporting_vq; + unsigned int unused, err; + + /* We should always be able to add these buffers to an empty queue. */ + err = virtqueue_add_inbuf(vq, ph_dev_info->sg, nents, vb, + GFP_NOWAIT | __GFP_NOWARN); + + /* + * In the extremely unlikely case that something has changed and we + * are able to trigger an error we will simply display a warning + * and exit without actually processing the pages. + */ + if (WARN_ON(err)) + return; + + virtqueue_kick(vq); + + /* When host has read buffer, this completes via balloon_ack */ + wait_event(vb->acked, virtqueue_get_buf(vq, &unused)); +} + static void set_page_pfns(struct virtio_balloon *vb, __virtio32 pfns[], struct page *page) { @@ -476,6 +511,7 @@ static int init_vqs(struct virtio_balloon *vb) names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate"; names[VIRTIO_BALLOON_VQ_STATS] = NULL; names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; + names[VIRTIO_BALLOON_VQ_REPORTING] = NULL; if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { names[VIRTIO_BALLOON_VQ_STATS] = "stats"; @@ -487,11 +523,19 @@ static int init_vqs(struct virtio_balloon *vb) callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; } + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) { + names[VIRTIO_BALLOON_VQ_REPORTING] = "reporting_vq"; + callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack; + } + err = vb->vdev->config->find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, vqs, callbacks, names, NULL, NULL); if (err) return err; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) + vb->reporting_vq = vqs[VIRTIO_BALLOON_VQ_REPORTING]; + vb->inflate_vq = vqs[VIRTIO_BALLOON_VQ_INFLATE]; vb->deflate_vq = vqs[VIRTIO_BALLOON_VQ_DEFLATE]; if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { @@ -930,12 +974,30 @@ static int virtballoon_probe(struct virtio_device *vdev) if (err) goto out_del_balloon_wq; } + + vb->ph_dev_info.report = virtballoon_unused_page_report; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) { + unsigned int capacity; + + capacity = min_t(unsigned int, + virtqueue_get_vring_size(vb->reporting_vq), + VIRTIO_BALLOON_VRING_HINTS_MAX); + vb->ph_dev_info.capacity = capacity; + + err = page_reporting_register(&vb->ph_dev_info); + if (err) + goto out_unregister_shrinker; + } + virtio_device_ready(vdev); if (towards_target(vb)) virtballoon_changed(vdev); return 0; +out_unregister_shrinker: + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) + virtio_balloon_unregister_shrinker(vb); out_del_balloon_wq: if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) destroy_workqueue(vb->balloon_wq); @@ -964,6 +1026,8 @@ static void virtballoon_remove(struct virtio_device *vdev) { struct virtio_balloon *vb = vdev->priv; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) + page_reporting_unregister(&vb->ph_dev_info); if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) virtio_balloon_unregister_shrinker(vb); spin_lock_irq(&vb->stop_update_lock); @@ -1035,6 +1099,7 @@ static int virtballoon_validate(struct virtio_device *vdev) VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_FREE_PAGE_HINT, VIRTIO_BALLOON_F_PAGE_POISON, + VIRTIO_BALLOON_F_REPORTING, }; static struct virtio_driver virtio_balloon_driver = { diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index a1966cd7b677..19974392d324 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -36,6 +36,7 @@ #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ #define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */ #define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */ +#define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12