From patchwork Wed Jul 27 01:23:36 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: 653040 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 3rzczD2C4gz9t1V for ; Wed, 27 Jul 2016 11:36:40 +1000 (AEST) Received: from localhost ([::1]:43222 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bSDm2-0008Dg-56 for incoming@patchwork.ozlabs.org; Tue, 26 Jul 2016 21:36:38 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49409) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bSDgu-0003Km-T5 for qemu-devel@nongnu.org; Tue, 26 Jul 2016 21:31:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bSDgs-0001Dy-Jb for qemu-devel@nongnu.org; Tue, 26 Jul 2016 21:31:19 -0400 Received: from mga09.intel.com ([134.134.136.24]:55626) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bSDgs-0001Dt-7U for qemu-devel@nongnu.org; Tue, 26 Jul 2016 21:31:18 -0400 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga102.jf.intel.com with ESMTP; 26 Jul 2016 18:31:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,427,1464678000"; d="scan'208";a="854199295" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.123]) by orsmga003.jf.intel.com with ESMTP; 26 Jul 2016 18:31:14 -0700 From: Liang Li To: linux-kernel@vger.kernel.org Date: Wed, 27 Jul 2016 09:23:36 +0800 Message-Id: <1469582616-5729-8-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> References: <1469582616-5729-1-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: 134.134.136.24 Subject: [Qemu-devel] [PATCH v2 repost 7/7] virtio-balloon: tell host vm's free 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 , qemu-devel@nongnu.org, dgilbert@redhat.com, linux-mm@kvack.org, "Michael S. Tsirkin" , Cornelia Huck , Paolo Bonzini , Andrew Morton , virtualization@lists.linux-foundation.org, Mel Gorman , Vlastimil Babka Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Support the request for vm's free page information, response with a page bitmap. QEMU can make use of this free page bitmap to speed up live migration process by skipping process the free pages. Signed-off-by: Liang Li Cc: Michael S. Tsirkin Cc: Andrew Morton Cc: Vlastimil Babka Cc: Mel Gorman Cc: Paolo Bonzini Cc: Cornelia Huck Cc: Amit Shah --- drivers/virtio/virtio_balloon.c | 104 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 98 insertions(+), 6 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 2d18ff6..5ca4ad3 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -62,10 +62,13 @@ module_param(oom_pages, int, S_IRUSR | S_IWUSR); MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); extern unsigned long get_max_pfn(void); +extern int get_free_pages(unsigned long start_pfn, unsigned long end_pfn, + unsigned long *bitmap, unsigned long len); + 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; @@ -89,6 +92,8 @@ struct virtio_balloon { unsigned long pfn_limit; /* 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. @@ -373,6 +378,49 @@ static void update_balloon_stats(struct virtio_balloon *vb) pages_to_bytes(available)); } +static void update_free_pages_stats(struct virtio_balloon *vb, + unsigned long req_id) +{ + struct scatterlist sg_in, sg_out; + unsigned long pfn = 0, bmap_len, max_pfn; + struct virtqueue *vq = vb->misc_vq; + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; + int ret = 1; + + max_pfn = get_max_pfn(); + mutex_lock(&vb->balloon_lock); + while (pfn < max_pfn) { + memset(vb->page_bitmap, 0, vb->bmap_len); + ret = get_free_pages(pfn, pfn + vb->pfn_limit, + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE); + hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_FREE_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 = vb->pfn_limit / BITS_PER_BYTE; + if (!ret) { + hdr->flag = cpu_to_virtio16(vb->vdev, + BALLOON_FLAG_DONE); + if (pfn + vb->pfn_limit > max_pfn) + bmap_len = (max_pfn - pfn) / BITS_PER_BYTE; + } else + hdr->flag = cpu_to_virtio16(vb->vdev, + BALLOON_FLAG_CONT); + hdr->bmap_len = cpu_to_virtio64(vb->vdev, bmap_len); + sg_init_one(&sg_out, hdr, + sizeof(struct balloon_bmap_hdr) + bmap_len); + + virtqueue_add_outbuf(vq, &sg_out, 1, vb, GFP_KERNEL); + virtqueue_kick(vq); + pfn += vb->pfn_limit; + } + + 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); + mutex_unlock(&vb->balloon_lock); +} + /* * While most virtqueues communicate guest-initiated requests to the hypervisor, * the stats queue operates in reverse. The driver initializes the virtqueue @@ -511,18 +559,49 @@ 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_FREE_PAGES: + update_free_pages_stats(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 + nvqs = virtio_has_feature(vb->vdev, + VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2; err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names); if (err) return err; @@ -543,6 +622,16 @@ 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; } @@ -639,8 +728,10 @@ static int virtballoon_probe(struct virtio_device *vdev) vb->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, 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); + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_MISC_VQ); + } else vb->page_bitmap = vb->bmap_hdr + hdr_len; mutex_init(&vb->balloon_lock); @@ -743,6 +834,7 @@ 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 = {