From patchwork Mon Aug 8 06:35:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Liang Z" X-Patchwork-Id: 656553 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3s77Ln4n2Nz9sR9 for ; Mon, 8 Aug 2016 16:49:37 +1000 (AEST) Received: from localhost ([::1]:55241 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWeNT-0007M9-8p for incoming@patchwork.ozlabs.org; Mon, 08 Aug 2016 02:49:35 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37613) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWeHh-0001ju-0u for qemu-devel@nongnu.org; Mon, 08 Aug 2016 02:43:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bWeHc-00083n-0n for qemu-devel@nongnu.org; Mon, 08 Aug 2016 02:43:36 -0400 Received: from mga01.intel.com ([192.55.52.88]:47922) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWeHb-00083j-N1 for qemu-devel@nongnu.org; Mon, 08 Aug 2016 02:43:31 -0400 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP; 07 Aug 2016 23:43:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,488,1464678000"; d="scan'208";a="861481664" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.123]) by orsmga003.jf.intel.com with ESMTP; 07 Aug 2016 23:43:28 -0700 From: Liang Li To: linux-kernel@vger.kernel.org Date: Mon, 8 Aug 2016 14:35:34 +0800 Message-Id: <1470638134-24149-8-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1470638134-24149-1-git-send-email-liang.z.li@intel.com> References: <1470638134-24149-1-git-send-email-liang.z.li@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.88 Subject: [Qemu-devel] [PATCH v3 kernel 7/7] virtio-balloon: tell host vm's unused page info X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, quintela@redhat.com, Amit Shah , Liang Li , dave.hansen@intel.com, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, "Michael S. Tsirkin" , Cornelia Huck , Paolo Bonzini , dgilbert@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Support the request for vm's unused page information, response with a page bitmap. QEMU can make use of this bitmap and the dirty page logging mechanism to skip the transportation of these unused pages, this is very helpful to speed up the live migration process. Signed-off-by: Liang Li Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Cornelia Huck Cc: Amit Shah Cc: Dave Hansen --- drivers/virtio/virtio_balloon.c | 143 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 134 insertions(+), 9 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index c31839c..f10bb8b 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -56,7 +56,7 @@ static struct vfsmount *balloon_mnt; struct virtio_balloon { struct virtio_device *vdev; - struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; + struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *misc_vq; /* The balloon servicing is delegated to a freezable workqueue. */ struct work_struct update_balloon_stats_work; @@ -78,6 +78,8 @@ struct virtio_balloon { unsigned int nr_page_bmap; /* Used to record the processed pfn range */ unsigned long min_pfn, max_pfn, start_pfn, end_pfn; + /* Request header */ + struct balloon_req_hdr req_hdr; /* * The pages we've told the Host we're not using are enqueued * at vb_dev_info->pages list. @@ -423,6 +425,78 @@ static void update_balloon_stats(struct virtio_balloon *vb) pages_to_bytes(available)); } +static void send_unused_pages_info(struct virtio_balloon *vb, + unsigned long req_id) +{ + struct scatterlist sg_in, sg_out[BALLOON_BMAP_COUNT + 1]; + unsigned long pfn = 0, bmap_len, pfn_limit, last_pfn, nr_pfn; + struct virtqueue *vq = vb->misc_vq; + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; + int ret = 1, nr_buf, used_nr_bmap = 0, i; + + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP) && + vb->nr_page_bmap == 1) + extend_page_bitmap(vb); + + pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap; + mutex_lock(&vb->balloon_lock); + last_pfn = get_max_pfn(); + + while (ret) { + clear_page_bitmap(vb); + ret = get_unused_pages(pfn, pfn + pfn_limit, vb->page_bitmap, + PFNS_PER_BMAP, vb->nr_page_bmap); + if (ret < 0) + break; + hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_UNUSED_PAGES); + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); + hdr->req_id = cpu_to_virtio64(vb->vdev, req_id); + hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn); + bmap_len = BALLOON_BMAP_SIZE * vb->nr_page_bmap; + + if (!ret) { + hdr->flag = cpu_to_virtio16(vb->vdev, + BALLOON_FLAG_DONE); + nr_pfn = last_pfn - pfn; + used_nr_bmap = nr_pfn / PFNS_PER_BMAP; + if (nr_pfn % PFNS_PER_BMAP) + used_nr_bmap++; + bmap_len = nr_pfn / BITS_PER_BYTE; + } else { + hdr->flag = cpu_to_virtio16(vb->vdev, + BALLOON_FLAG_CONT); + used_nr_bmap = vb->nr_page_bmap; + } + hdr->bmap_len = cpu_to_virtio64(vb->vdev, bmap_len); + nr_buf = used_nr_bmap + 1; + sg_init_table(sg_out, nr_buf); + sg_set_buf(&sg_out[0], hdr, sizeof(struct balloon_bmap_hdr)); + for (i = 0; i < used_nr_bmap; i++) { + unsigned int buf_len = BALLOON_BMAP_SIZE; + + if (i + 1 == used_nr_bmap) + buf_len = bmap_len - BALLOON_BMAP_SIZE * i; + sg_set_buf(&sg_out[i + 1], vb->page_bitmap[i], buf_len); + } + + while (vq->num_free < nr_buf) + msleep(2); + if (virtqueue_add_outbuf(vq, sg_out, nr_buf, vb, + GFP_KERNEL) == 0) { + virtqueue_kick(vq); + while (!virtqueue_get_buf(vq, &i) + && !virtqueue_is_broken(vq)) + cpu_relax(); + } + pfn += pfn_limit; + } + + mutex_unlock(&vb->balloon_lock); + sg_init_one(&sg_in, &vb->req_hdr, sizeof(vb->req_hdr)); + virtqueue_add_inbuf(vq, &sg_in, 1, &vb->req_hdr, GFP_KERNEL); + virtqueue_kick(vq); +} + /* * While most virtqueues communicate guest-initiated requests to the hypervisor, * the stats queue operates in reverse. The driver initializes the virtqueue @@ -563,18 +637,56 @@ static void update_balloon_size_func(struct work_struct *work) queue_work(system_freezable_wq, work); } +static void misc_handle_rq(struct virtio_balloon *vb) +{ + struct balloon_req_hdr *ptr_hdr; + unsigned int len; + + ptr_hdr = virtqueue_get_buf(vb->misc_vq, &len); + if (!ptr_hdr || len != sizeof(vb->req_hdr)) + return; + + switch (ptr_hdr->cmd) { + case BALLOON_GET_UNUSED_PAGES: + send_unused_pages_info(vb, ptr_hdr->param); + break; + default: + break; + } +} + +static void misc_request(struct virtqueue *vq) +{ + struct virtio_balloon *vb = vq->vdev->priv; + + misc_handle_rq(vb); +} + static int init_vqs(struct virtio_balloon *vb) { - struct virtqueue *vqs[3]; - vq_callback_t *callbacks[] = { balloon_ack, balloon_ack, stats_request }; - static const char * const names[] = { "inflate", "deflate", "stats" }; + struct virtqueue *vqs[4]; + vq_callback_t *callbacks[] = { balloon_ack, balloon_ack, + stats_request, misc_request }; + static const char * const names[] = { "inflate", "deflate", "stats", + "misc" }; int err, nvqs; /* * We expect two virtqueues: inflate and deflate, and * optionally stat. */ - nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ)) + nvqs = 4; + else if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) + nvqs = 3; + else + nvqs = 2; + + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { + __virtio_clear_bit(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP); + __virtio_clear_bit(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ); + } + err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names); if (err) return err; @@ -595,6 +707,16 @@ static int init_vqs(struct virtio_balloon *vb) BUG(); virtqueue_kick(vb->stats_vq); } + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_MISC_VQ)) { + struct scatterlist sg_in; + + vb->misc_vq = vqs[3]; + sg_init_one(&sg_in, &vb->req_hdr, sizeof(vb->req_hdr)); + if (virtqueue_add_inbuf(vb->misc_vq, &sg_in, 1, + &vb->req_hdr, GFP_KERNEL) < 0) + BUG(); + virtqueue_kick(vb->misc_vq); + } return 0; } @@ -703,13 +825,15 @@ static int virtballoon_probe(struct virtio_device *vdev) vb->num_pages = 0; vb->bmap_hdr = kzalloc(sizeof(struct balloon_bmap_hdr), GFP_KERNEL); /* Clear the feature bit if memory allocation fails */ - if (!vb->bmap_hdr) + if (!vb->bmap_hdr) { __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP); - else { + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_MISC_VQ); + } else { vb->page_bitmap[0] = kmalloc(BALLOON_BMAP_SIZE, GFP_KERNEL); - if (!vb->page_bitmap[0]) + if (!vb->page_bitmap[0]) { __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP); - else + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_MISC_VQ); + } else vb->nr_page_bmap = 1; } mutex_init(&vb->balloon_lock); @@ -832,6 +956,7 @@ static unsigned int features[] = { VIRTIO_BALLOON_F_STATS_VQ, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_PAGE_BITMAP, + VIRTIO_BALLOON_F_MISC_VQ, }; static struct virtio_driver virtio_balloon_driver = {