From patchwork Tue Nov 19 21:46:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11252725 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 59A441390 for ; Tue, 19 Nov 2019 21:46:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A0342240D for ; Tue, 19 Nov 2019 21:46:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dDh5zWmw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A0342240D 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 3A4186B000D; Tue, 19 Nov 2019 16:46:57 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 353C96B000E; Tue, 19 Nov 2019 16:46:57 -0500 (EST) 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 2693E6B0010; Tue, 19 Nov 2019 16:46:57 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0114.hostedemail.com [216.40.44.114]) by kanga.kvack.org (Postfix) with ESMTP id 1378E6B000D for ; Tue, 19 Nov 2019 16:46:57 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id D0BF052BB for ; Tue, 19 Nov 2019 21:46:56 +0000 (UTC) X-FDA: 76174362432.22.front53_25d7218f9742 X-Spam-Summary: 2,0,0,07b8bf5d5b60619a,d41d8cd98f00b204,alexander.duyck@gmail.com,:kvm@vger.kernel.org:mst@redhat.com:linux-kernel@vger.kernel.org:willy@infradead.org:mhocko@kernel.org::akpm@linux-foundation.org:mgorman@techsingularity.net:vbabka@suse.cz: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,RULES_HIT:1:2:41:152:355:379:960:966:968:973:988:989:1260:1277:1311:1313:1314:1345:1359:1431:1437:1515:1516:1518:1593:1594:1605:1730:1747:1777:1792:2196:2198:2199:2200:2393:2559:2562:2693:2918:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:3874:4049:4250:4321:4385:4605:5007:6119:6261:6653:6742:7576:7903:8603:9010:9413:10004:11026:11473:11658:11914:12043:12048:12291:12294:12296:12297:12438:12517:12519:12555:12679:12683:1276 0:12986: X-HE-Tag: front53_25d7218f9742 X-Filterd-Recvd-Size: 10441 Received: from mail-pg1-f196.google.com (mail-pg1-f196.google.com [209.85.215.196]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 Nov 2019 21:46:56 +0000 (UTC) Received: by mail-pg1-f196.google.com with SMTP id 207so4787587pge.8 for ; Tue, 19 Nov 2019 13:46:56 -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=Kl7ZJlmi7sBAeFCxqsbtJTyoIeGJbf1TWCrAFqF4sF0=; b=dDh5zWmw89XUR6rt+NuvA0RzAyanbPwC0pFjKj6QivU5iom7LKXqS7X5AV1LoTMkw7 k90kIDzDrR6Ld0SRZARp8jp8AjYWI6buJ0IukVCGaclJVhwC8csIMYNuYKwjZwnOUbu+ AQi93jPEPyzsr+wdNRnoltIoBFtq+iNCFiJqi5yOkG6BYAK2DY62SoE2gvCSNs/Nqkvz Du/ruvnP7Jcldq16LMh2xQL/W0OZ3mmPqkTdpeAS5xQ8aoJmhuwoLfyeqTB5/IhImv+j /Jk0gUpP9ae9ojzzePg7I5k/1tApsgjT7Yd/S/Z2QD/RzQZCroo+6QXN3djn85ABMuGO gf3Q== 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=Kl7ZJlmi7sBAeFCxqsbtJTyoIeGJbf1TWCrAFqF4sF0=; b=eYjmbEGA2zX8+LgRqbheJD/8JzAfcyhFeYVsdZB9ZZFPJeI6yRfVj4rq7i+pTGFC9g 8toZQgZ1Jx9Eke1uBJOhfp2uIHoTzz5hSMKORsOirgdTTRDopfsTOYlLa+YUO0zG1ReQ vh2THxmXe9VnVpNG4xZABPUV5zK67S9NcFFlR83W2dsm9E8tzXwirUoJN2o8brb/6PKK ZV4yuj0Ff6efw13eLI625rvqps3/CA5Tf466OZWBZ24ra3M5Nd/vjnjAPdBMcDUXcxq7 HMwI2z5qdyFVjJ5NDRJE2rFW62rEMzZHHUeN+F/sbekYPQyMUxcs1EASPnLk4VngCStD 2ecw== X-Gm-Message-State: APjAAAVUS0jw9VT0Y0ZqrZ/IxmMW0zXSNUSwxiAR4WFa26k1gH7oRozS PvUkkgUMNsuiSFrYmJAivcU= X-Google-Smtp-Source: APXvYqyA/cKB0w3sWtf/5xsd9cV6ZDGpzcUeIxAjzkBlNKmEvLxp/2NK95GJfyTb7oFfdNUHkstGqg== X-Received: by 2002:a63:3f4e:: with SMTP id m75mr7867766pga.392.1574200015079; Tue, 19 Nov 2019 13:46:55 -0800 (PST) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id o15sm23710284pgn.49.2019.11.19.13.46.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 19 Nov 2019 13:46:54 -0800 (PST) Subject: [PATCH v14 6/6] virtio-balloon: Add support for providing unused page reports to host 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, 19 Nov 2019 13:46:53 -0800 Message-ID: <20191119214653.24996.90695.stgit@localhost.localdomain> In-Reply-To: <20191119214454.24996.66289.stgit@localhost.localdomain> References: <20191119214454.24996.66289.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 92099298bc16..6f5c6555765a 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 pr_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 *pr_dev_info, + unsigned int nents) +{ + struct virtio_balloon *vb = + container_of(pr_dev_info, struct virtio_balloon, pr_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, pr_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)) { @@ -932,12 +976,30 @@ static int virtballoon_probe(struct virtio_device *vdev) if (err) goto out_del_balloon_wq; } + + vb->pr_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->pr_dev_info.capacity = capacity; + + err = page_reporting_register(&vb->pr_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); @@ -966,6 +1028,8 @@ 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->pr_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); @@ -1038,6 +1102,7 @@ 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