From patchwork Mon Dec 3 02:18:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10708547 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8D37513AD for ; Mon, 3 Dec 2018 02:58:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 769F32A679 for ; Mon, 3 Dec 2018 02:58:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 659C32A7C6; Mon, 3 Dec 2018 02:58:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4FFBA2A679 for ; Mon, 3 Dec 2018 02:58:30 +0000 (UTC) Received: from localhost ([::1]:46571 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gTeRJ-00008d-Ea for patchwork-qemu-devel@patchwork.kernel.org; Sun, 02 Dec 2018 21:58:29 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49955) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gTeKo-00013W-VM for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gTeKm-0000en-Rz for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:46 -0500 Received: from mga07.intel.com ([134.134.136.100]:65450) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gTeKm-0000Zq-HV for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:44 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Dec 2018 18:51:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,308,1539673200"; d="scan'208";a="115254802" Received: from devel-ww.sh.intel.com ([10.239.48.119]) by FMSMGA003.fm.intel.com with ESMTP; 02 Dec 2018 18:51:42 -0800 From: Wei Wang To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com, peterx@redhat.com Date: Mon, 3 Dec 2018 10:18:31 +0800 Message-Id: <1543803511-34793-8-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1543803511-34793-1-git-send-email-wei.w.wang@intel.com> References: <1543803511-34793-1-git-send-email-wei.w.wang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.100 Subject: [Qemu-devel] [PATCH v10 7/7] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT 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: pbonzini@redhat.com, liliang.opensource@gmail.com, nilal@redhat.com, wei.w.wang@intel.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The new feature enables the virtio-balloon device to receive hints of guest free pages from the free page vq. A notifier is registered to the migration precopy notifier chain. The notifier calls free_page_start after the migration thread syncs the dirty bitmap, so that the free page optimization starts to clear bits of free pages from the bitmap. It calls the free_page_stop before the migration thread syncs the bitmap, which is the end of the current round of ram save. The free_page_stop is also called to stop the optimization in the case when there is an error occurred in the process of ram saving. Note: balloon will report pages which were free at the time of this call. As the reporting happens asynchronously, dirty bit logging must be enabled before this free_page_start call is made. Guest reporting must be disabled before the migration dirty bitmap is synchronized. Signed-off-by: Wei Wang CC: Michael S. Tsirkin CC: Dr. David Alan Gilbert CC: Juan Quintela CC: Peter Xu --- hw/virtio/virtio-balloon.c | 263 ++++++++++++++++++++++++ include/hw/virtio/virtio-balloon.h | 28 ++- include/standard-headers/linux/virtio_balloon.h | 5 + 3 files changed, 295 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 1728e4f..5376f9b 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -27,6 +27,7 @@ #include "qapi/visitor.h" #include "trace.h" #include "qemu/error-report.h" +#include "migration/misc.h" #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" @@ -308,6 +309,184 @@ out: } } +static void virtio_balloon_handle_free_page_vq(VirtIODevice *vdev, + VirtQueue *vq) +{ + VirtIOBalloon *s = VIRTIO_BALLOON(vdev); + qemu_bh_schedule(s->free_page_bh); +} + +static bool get_free_page_hints(VirtIOBalloon *dev) +{ + VirtQueueElement *elem; + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtQueue *vq = dev->free_page_vq; + + while (dev->block_iothread) { + qemu_cond_wait(&dev->free_page_cond, &dev->free_page_lock); + } + + elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); + if (!elem) { + return false; + } + + if (elem->out_num) { + uint32_t id; + size_t size = iov_to_buf(elem->out_sg, elem->out_num, 0, + &id, sizeof(id)); + virtqueue_push(vq, elem, size); + g_free(elem); + + virtio_tswap32s(vdev, &id); + if (unlikely(size != sizeof(id))) { + virtio_error(vdev, "received an incorrect cmd id"); + return false; + } + if (id == dev->free_page_report_cmd_id) { + dev->free_page_report_status = FREE_PAGE_REPORT_S_START; + } else { + /* + * Stop the optimization only when it has started. This + * avoids a stale stop sign for the previous command. + */ + if (dev->free_page_report_status == FREE_PAGE_REPORT_S_START) { + dev->free_page_report_status = FREE_PAGE_REPORT_S_STOP; + } + } + } + + if (elem->in_num) { + if (dev->free_page_report_status == FREE_PAGE_REPORT_S_START) { + qemu_guest_free_page_hint(elem->in_sg[0].iov_base, + elem->in_sg[0].iov_len); + } + virtqueue_push(vq, elem, 1); + g_free(elem); + } + + return true; +} + +static void virtio_ballloon_get_free_page_hints(void *opaque) +{ + VirtIOBalloon *dev = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtQueue *vq = dev->free_page_vq; + bool continue_to_get_hints; + + do { + qemu_mutex_lock(&dev->free_page_lock); + virtio_queue_set_notification(vq, 0); + continue_to_get_hints = get_free_page_hints(dev); + qemu_mutex_unlock(&dev->free_page_lock); + virtio_notify(vdev, vq); + /* + * Start to poll the vq once the reporting started. Otherwise, continue + * only when there are entries on the vq, which need to be given back. + */ + } while (continue_to_get_hints || + dev->free_page_report_status == FREE_PAGE_REPORT_S_START); + virtio_queue_set_notification(vq, 1); +} + +static bool virtio_balloon_free_page_support(void *opaque) +{ + VirtIOBalloon *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT); +} + +static void virtio_balloon_free_page_start(VirtIOBalloon *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + /* For the stop and copy phase, we don't need to start the optimization */ + if (!vdev->vm_running) { + return; + } + + if (s->free_page_report_cmd_id == UINT_MAX) { + s->free_page_report_cmd_id = + VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN; + } else { + s->free_page_report_cmd_id++; + } + + s->free_page_report_status = FREE_PAGE_REPORT_S_REQUESTED; + virtio_notify_config(vdev); +} + +static void virtio_balloon_free_page_stop(VirtIOBalloon *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + if (s->free_page_report_status != FREE_PAGE_REPORT_S_STOP) { + /* + * The lock also guarantees us that the + * virtio_ballloon_get_free_page_hints exits after the + * free_page_report_status is set to S_STOP. + */ + qemu_mutex_lock(&s->free_page_lock); + /* + * The guest hasn't done the reporting, so host sends a notification + * to the guest to actively stop the reporting. + */ + s->free_page_report_status = FREE_PAGE_REPORT_S_STOP; + qemu_mutex_unlock(&s->free_page_lock); + virtio_notify_config(vdev); + } +} + +static void virtio_balloon_free_page_done(VirtIOBalloon *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + s->free_page_report_status = FREE_PAGE_REPORT_S_DONE; + virtio_notify_config(vdev); +} + +static int +virtio_balloon_free_page_report_notify(NotifierWithReturn *n, void *data) +{ + VirtIOBalloon *dev = container_of(n, VirtIOBalloon, + free_page_report_notify); + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + PrecopyNotifyData *pnd = data; + + if (!virtio_balloon_free_page_support(dev)) { + /* + * This is an optimization provided to migration, so just return 0 to + * have the normal migration process not affected when this feature is + * not supported. + */ + return 0; + } + + switch (pnd->reason) { + case PRECOPY_NOTIFY_SETUP: + precopy_disable_bulk_stage(); + break; + case PRECOPY_NOTIFY_COMPLETE: + case PRECOPY_NOTIFY_CLEANUP: + case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC: + virtio_balloon_free_page_stop(dev); + break; + case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC: + if (vdev->vm_running) { + virtio_balloon_free_page_start(dev); + } else { + virtio_balloon_free_page_done(dev); + } + break; + default: + virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason); + } + + return 0; +} + static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) { VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); @@ -316,6 +495,17 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) config.num_pages = cpu_to_le32(dev->num_pages); config.actual = cpu_to_le32(dev->actual); + if (dev->free_page_report_status == FREE_PAGE_REPORT_S_REQUESTED) { + config.free_page_report_cmd_id = + cpu_to_le32(dev->free_page_report_cmd_id); + } else if (dev->free_page_report_status == FREE_PAGE_REPORT_S_STOP) { + config.free_page_report_cmd_id = + cpu_to_le32(VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID); + } else if (dev->free_page_report_status == FREE_PAGE_REPORT_S_DONE) { + config.free_page_report_cmd_id = + cpu_to_le32(VIRTIO_BALLOON_FREE_PAGE_REPORT_DONE_ID); + } + trace_virtio_balloon_get_config(config.num_pages, config.actual); memcpy(config_data, &config, sizeof(struct virtio_balloon_config)); } @@ -376,6 +566,7 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f, VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); f |= dev->host_features; virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ); + return f; } @@ -412,6 +603,18 @@ static int virtio_balloon_post_load_device(void *opaque, int version_id) return 0; } +static const VMStateDescription vmstate_virtio_balloon_free_page_report = { + .name = "virtio-balloon-device/free-page-report", + .version_id = 1, + .minimum_version_id = 1, + .needed = virtio_balloon_free_page_support, + .fields = (VMStateField[]) { + VMSTATE_UINT32(free_page_report_cmd_id, VirtIOBalloon), + VMSTATE_UINT32(free_page_report_status, VirtIOBalloon), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_virtio_balloon_device = { .name = "virtio-balloon-device", .version_id = 1, @@ -422,6 +625,10 @@ static const VMStateDescription vmstate_virtio_balloon_device = { VMSTATE_UINT32(actual, VirtIOBalloon), VMSTATE_END_OF_LIST() }, + .subsections = (const VMStateDescription * []) { + &vmstate_virtio_balloon_free_page_report, + NULL + } }; static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) @@ -446,6 +653,29 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats); + if (virtio_has_feature(s->host_features, + VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { + s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE, + virtio_balloon_handle_free_page_vq); + s->free_page_report_status = FREE_PAGE_REPORT_S_STOP; + s->free_page_report_cmd_id = + VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN; + s->free_page_report_notify.notify = + virtio_balloon_free_page_report_notify; + precopy_add_notifier(&s->free_page_report_notify); + if (s->iothread) { + object_ref(OBJECT(s->iothread)); + s->free_page_bh = aio_bh_new(iothread_get_aio_context(s->iothread), + virtio_ballloon_get_free_page_hints, s); + qemu_mutex_init(&s->free_page_lock); + qemu_cond_init(&s->free_page_cond); + s->block_iothread = false; + } else { + /* Simply disable this feature if the iothread wasn't created. */ + s->host_features &= ~(1 << VIRTIO_BALLOON_F_FREE_PAGE_HINT); + virtio_error(vdev, "iothread is missing"); + } + } reset_stats(s); } @@ -454,6 +684,11 @@ static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp) VirtIODevice *vdev = VIRTIO_DEVICE(dev); VirtIOBalloon *s = VIRTIO_BALLOON(dev); + if (virtio_balloon_free_page_support(s)) { + qemu_bh_delete(s->free_page_bh); + virtio_balloon_free_page_stop(s); + precopy_remove_notifier(&s->free_page_report_notify); + } balloon_stats_destroy_timer(s); qemu_remove_balloon_handler(s); virtio_cleanup(vdev); @@ -463,6 +698,10 @@ static void virtio_balloon_device_reset(VirtIODevice *vdev) { VirtIOBalloon *s = VIRTIO_BALLOON(vdev); + if (virtio_balloon_free_page_support(s)) { + virtio_balloon_free_page_stop(s); + } + if (s->stats_vq_elem != NULL) { virtqueue_unpop(s->svq, s->stats_vq_elem, 0); g_free(s->stats_vq_elem); @@ -480,6 +719,26 @@ static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status) * was stopped */ virtio_balloon_receive_stats(vdev, s->svq); } + + if (virtio_balloon_free_page_support(s)) { + /* + * The VM is woken up and the iothread was blocked, so signal it to + * continue. + */ + if (vdev->vm_running && s->block_iothread) { + qemu_mutex_lock(&s->free_page_lock); + s->block_iothread = false; + qemu_cond_signal(&s->free_page_cond); + qemu_mutex_unlock(&s->free_page_lock); + } + + /* The VM is stopped, block the iothread. */ + if (!vdev->vm_running) { + qemu_mutex_lock(&s->free_page_lock); + s->block_iothread = true; + qemu_mutex_unlock(&s->free_page_lock); + } + } } static void virtio_balloon_instance_init(Object *obj) @@ -508,6 +767,10 @@ static const VMStateDescription vmstate_virtio_balloon = { static Property virtio_balloon_properties[] = { DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false), + DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features, + VIRTIO_BALLOON_F_FREE_PAGE_HINT, false), + DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD, + IOThread *), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h index e0df352..503349a 100644 --- a/include/hw/virtio/virtio-balloon.h +++ b/include/hw/virtio/virtio-balloon.h @@ -17,11 +17,14 @@ #include "standard-headers/linux/virtio_balloon.h" #include "hw/virtio/virtio.h" +#include "sysemu/iothread.h" #define TYPE_VIRTIO_BALLOON "virtio-balloon-device" #define VIRTIO_BALLOON(obj) \ OBJECT_CHECK(VirtIOBalloon, (obj), TYPE_VIRTIO_BALLOON) +#define VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN 0x80000000 + typedef struct virtio_balloon_stat VirtIOBalloonStat; typedef struct virtio_balloon_stat_modern { @@ -30,15 +33,38 @@ typedef struct virtio_balloon_stat_modern { uint64_t val; } VirtIOBalloonStatModern; +enum virtio_balloon_free_page_report_status { + FREE_PAGE_REPORT_S_STOP = 0, + FREE_PAGE_REPORT_S_REQUESTED = 1, + FREE_PAGE_REPORT_S_START = 2, + FREE_PAGE_REPORT_S_DONE = 3, +}; + typedef struct VirtIOBalloon { VirtIODevice parent_obj; - VirtQueue *ivq, *dvq, *svq; + VirtQueue *ivq, *dvq, *svq, *free_page_vq; + uint32_t free_page_report_status; uint32_t num_pages; uint32_t actual; + uint32_t free_page_report_cmd_id; uint64_t stats[VIRTIO_BALLOON_S_NR]; VirtQueueElement *stats_vq_elem; size_t stats_vq_offset; QEMUTimer *stats_timer; + IOThread *iothread; + QEMUBH *free_page_bh; + /* + * Lock to synchronize threads to access the free page reporting related + * fields (e.g. free_page_report_status). + */ + QemuMutex free_page_lock; + QemuCond free_page_cond; + /* + * Set to block iothread to continue reading free page hints as the VM is + * stopped. + */ + bool block_iothread; + NotifierWithReturn free_page_report_notify; int64_t stats_last_update; int64_t stats_poll_interval; uint32_t host_features; diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h index 4dbb7dc..9eee1c6 100644 --- a/include/standard-headers/linux/virtio_balloon.h +++ b/include/standard-headers/linux/virtio_balloon.h @@ -34,15 +34,20 @@ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ #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_FREE_PAGE_HINT 3 /* VQ to report free pages */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 +#define VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID 0 +#define VIRTIO_BALLOON_FREE_PAGE_REPORT_DONE_ID 1 struct virtio_balloon_config { /* Number of pages host wants Guest to give up. */ uint32_t num_pages; /* Number of pages we've actually got in balloon. */ uint32_t actual; + /* Free page report command id, readonly by guest */ + uint32_t free_page_report_cmd_id; }; #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */