Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751956AbdHCGtf (ORCPT ); Thu, 3 Aug 2017 02:49:35 -0400 Received: from mga09.intel.com ([134.134.136.24]:33123 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751131AbdHCGsw (ORCPT ); Thu, 3 Aug 2017 02:48:52 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,314,1498546800"; d="scan'208";a="1158532694" From: Wei Wang To: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, mawilcox@microsoft.com, akpm@linux-foundation.org Cc: virtio-dev@lists.oasis-open.org, david@redhat.com, cornelia.huck@de.ibm.com, mgorman@techsingularity.net, aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu@aliyun.com Subject: [PATCH v13 5/5] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_VQ Date: Thu, 3 Aug 2017 14:38:19 +0800 Message-Id: <1501742299-4369-6-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1501742299-4369-1-git-send-email-wei.w.wang@intel.com> References: <1501742299-4369-1-git-send-email-wei.w.wang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9284 Lines: 293 Add a new vq to report hints of guest free pages to the host. Signed-off-by: Wei Wang Signed-off-by: Liang Li --- drivers/virtio/virtio_balloon.c | 164 ++++++++++++++++++++++++++++++------ include/uapi/linux/virtio_balloon.h | 1 + 2 files changed, 140 insertions(+), 25 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 29aca0c..29c4a61 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -54,11 +54,12 @@ 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, *free_page_vq; /* The balloon servicing is delegated to a freezable workqueue. */ struct work_struct update_balloon_stats_work; struct work_struct update_balloon_size_work; + struct work_struct report_free_page_work; /* Prevent updating balloon when it is being canceled. */ spinlock_t stop_update_lock; @@ -90,6 +91,13 @@ struct virtio_balloon { /* Memory statistics */ struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR]; + /* + * Used by the device and driver to signal each other. + * device->driver: start the free page report. + * driver->device: end the free page report. + */ + __virtio32 report_free_page_signal; + /* To register callback in oom notifier call chain */ struct notifier_block nb; }; @@ -146,7 +154,7 @@ static void set_page_pfns(struct virtio_balloon *vb, } static void send_one_sg(struct virtio_balloon *vb, struct virtqueue *vq, - void *addr, uint32_t size) + void *addr, uint32_t size, bool busywait) { struct scatterlist sg; unsigned int len; @@ -165,7 +173,12 @@ static void send_one_sg(struct virtio_balloon *vb, struct virtqueue *vq, cpu_relax(); } virtqueue_kick(vq); - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); + if (busywait) + while (!virtqueue_get_buf(vq, &len) && + !virtqueue_is_broken(vq)) + cpu_relax(); + else + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); } /* @@ -197,11 +210,11 @@ static void tell_host_sgs(struct virtio_balloon *vb, sg_addr = pfn_to_kaddr(sg_pfn_start); sg_len = (sg_pfn_end - sg_pfn_start) << PAGE_SHIFT; while (sg_len > sg_max_len) { - send_one_sg(vb, vq, sg_addr, sg_max_len); + send_one_sg(vb, vq, sg_addr, sg_max_len, 0); sg_addr += sg_max_len; sg_len -= sg_max_len; } - send_one_sg(vb, vq, sg_addr, sg_len); + send_one_sg(vb, vq, sg_addr, sg_len, 0); xb_zero(&vb->page_xb, sg_pfn_start, sg_pfn_end); sg_pfn_start = sg_pfn_end + 1; } @@ -503,42 +516,138 @@ static void update_balloon_size_func(struct work_struct *work) queue_work(system_freezable_wq, work); } +static void virtio_balloon_send_free_pages(void *opaque, unsigned long pfn, + unsigned long nr_pages) +{ + struct virtio_balloon *vb = (struct virtio_balloon *)opaque; + void *addr = pfn_to_kaddr(pfn); + uint32_t len = nr_pages << PAGE_SHIFT; + + send_one_sg(vb, vb->free_page_vq, addr, len, 1); +} + +static void report_free_page_completion(struct virtio_balloon *vb) +{ + struct virtqueue *vq = vb->free_page_vq; + struct scatterlist sg; + unsigned int len; + + sg_init_one(&sg, &vb->report_free_page_signal, sizeof(__virtio32)); + while (unlikely(virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL) + == -ENOSPC)) { + virtqueue_kick(vq); + while (!virtqueue_get_buf(vq, &len) && + !virtqueue_is_broken(vq)) + cpu_relax(); + } + virtqueue_kick(vq); +} + +static void report_free_page(struct work_struct *work) +{ + struct virtio_balloon *vb; + + vb = container_of(work, struct virtio_balloon, report_free_page_work); + walk_free_mem_block(vb, 1, &virtio_balloon_send_free_pages); + report_free_page_completion(vb); +} + +static void free_page_request(struct virtqueue *vq) +{ + struct virtio_balloon *vb = vq->vdev->priv; + + queue_work(system_freezable_wq, &vb->report_free_page_work); +} + 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" }; - int err, nvqs; + struct virtqueue **vqs; + vq_callback_t **callbacks; + const char **names; + struct scatterlist sg; + int i, nvqs, err = -ENOMEM; + + /* Inflateq and deflateq are used unconditionally */ + nvqs = 2; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) + nvqs++; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_VQ)) + nvqs++; + + /* Allocate space for find_vqs parameters */ + vqs = kcalloc(nvqs, sizeof(*vqs), GFP_KERNEL); + if (!vqs) + goto err_vq; + callbacks = kmalloc_array(nvqs, sizeof(*callbacks), GFP_KERNEL); + if (!callbacks) + goto err_callback; + names = kmalloc_array(nvqs, sizeof(*names), GFP_KERNEL); + if (!names) + goto err_names; + + callbacks[0] = balloon_ack; + names[0] = "inflate"; + callbacks[1] = balloon_ack; + names[1] = "deflate"; + + i = 2; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { + callbacks[i] = stats_request; + names[i] = "stats"; + i++; + } - /* - * We expect two virtqueues: inflate and deflate, and - * optionally stat. - */ - nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2; - err = virtio_find_vqs(vb->vdev, nvqs, vqs, callbacks, names, NULL); + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_VQ)) { + callbacks[i] = free_page_request; + names[i] = "free_page_vq"; + } + + err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names, + NULL, NULL); if (err) - return err; + goto err_find; vb->inflate_vq = vqs[0]; vb->deflate_vq = vqs[1]; + i = 2; if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { - struct scatterlist sg; - unsigned int num_stats; - vb->stats_vq = vqs[2]; - + vb->stats_vq = vqs[i++]; /* * Prime this virtqueue with one buffer so the hypervisor can * use it to signal us later (it can't be broken yet!). */ - num_stats = update_balloon_stats(vb); - - sg_init_one(&sg, vb->stats, sizeof(vb->stats[0]) * num_stats); + sg_init_one(&sg, vb->stats, sizeof(vb->stats)); if (virtqueue_add_outbuf(vb->stats_vq, &sg, 1, vb, GFP_KERNEL) < 0) BUG(); virtqueue_kick(vb->stats_vq); } + + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_VQ)) { + vb->free_page_vq = vqs[i]; + vb->report_free_page_signal = 0; + sg_init_one(&sg, &vb->report_free_page_signal, + sizeof(__virtio32)); + if (virtqueue_add_outbuf(vb->free_page_vq, &sg, 1, vb, + GFP_KERNEL) < 0) + dev_warn(&vb->vdev->dev, "%s: add signal buf fail\n", + __func__); + virtqueue_kick(vb->free_page_vq); + } + + kfree(names); + kfree(callbacks); + kfree(vqs); return 0; + +err_find: + kfree(names); +err_names: + kfree(callbacks); +err_callback: + kfree(vqs); +err_vq: + return err; } #ifdef CONFIG_BALLOON_COMPACTION @@ -590,7 +699,7 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags); if (use_sg) { send_one_sg(vb, vb->inflate_vq, page_address(newpage), - PAGE_SIZE); + PAGE_SIZE, 0); } else { vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; set_page_pfns(vb, vb->pfns, newpage); @@ -600,7 +709,7 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, balloon_page_delete(page); if (use_sg) { send_one_sg(vb, vb->deflate_vq, page_address(page), - PAGE_SIZE); + PAGE_SIZE, 0); } else { vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; set_page_pfns(vb, vb->pfns, page); @@ -667,6 +776,9 @@ static int virtballoon_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_SG)) xb_init(&vb->page_xb); + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_VQ)) + INIT_WORK(&vb->report_free_page_work, report_free_page); + vb->nb.notifier_call = virtballoon_oom_notify; vb->nb.priority = VIRTBALLOON_OOM_NOTIFY_PRIORITY; err = register_oom_notifier(&vb->nb); @@ -731,6 +843,7 @@ static void virtballoon_remove(struct virtio_device *vdev) spin_unlock_irq(&vb->stop_update_lock); cancel_work_sync(&vb->update_balloon_size_work); cancel_work_sync(&vb->update_balloon_stats_work); + cancel_work_sync(&vb->report_free_page_work); xb_empty(&vb->page_xb); remove_common(vb); @@ -785,6 +898,7 @@ static unsigned int features[] = { VIRTIO_BALLOON_F_STATS_VQ, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_SG, + VIRTIO_BALLOON_F_FREE_PAGE_VQ, }; static struct virtio_driver virtio_balloon_driver = { diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 37780a7..8214f84 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -35,6 +35,7 @@ #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ #define VIRTIO_BALLOON_F_SG 3 /* Use sg instead of PFN lists */ +#define VIRTIO_BALLOON_F_FREE_PAGE_VQ 4 /* Virtqueue to report free pages */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 -- 2.7.4