From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1F97C742A2 for ; Thu, 11 Jul 2019 18:56:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 921F820863 for ; Thu, 11 Jul 2019 18:56:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729062AbfGKS40 (ORCPT ); Thu, 11 Jul 2019 14:56:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48570 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728978AbfGKS40 (ORCPT ); Thu, 11 Jul 2019 14:56:26 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7502C308FC4B; Thu, 11 Jul 2019 18:56:25 +0000 (UTC) Received: from redhat.com (ovpn-116-67.ams2.redhat.com [10.36.116.67]) by smtp.corp.redhat.com (Postfix) with SMTP id 3B38A5D9CC; Thu, 11 Jul 2019 18:56:01 +0000 (UTC) Date: Thu, 11 Jul 2019 14:55:59 -0400 From: "Michael S. Tsirkin" To: Nitesh Narayan Lal Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pbonzini@redhat.com, lcapitulino@redhat.com, pagupta@redhat.com, wei.w.wang@intel.com, yang.zhang.wz@gmail.com, riel@surriel.com, david@redhat.com, dodgen@google.com, konrad.wilk@oracle.com, dhildenb@redhat.com, aarcange@redhat.com, alexander.duyck@gmail.com, john.starks@microsoft.com, dave.hansen@intel.com, mhocko@suse.com Subject: Re: [QEMU Patch] virtio-baloon: Support for page hinting Message-ID: <20190711141036-mutt-send-email-mst@kernel.org> References: <20190710195158.19640-1-nitesh@redhat.com> <20190710195303.19690-1-nitesh@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190710195303.19690-1-nitesh@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Thu, 11 Jul 2019 18:56:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 10, 2019 at 03:53:03PM -0400, Nitesh Narayan Lal wrote: > Enables QEMU to perform madvise free on the memory range reported > by the vm. > > Signed-off-by: Nitesh Narayan Lal Missing second "l" in the subject :) > --- > hw/virtio/trace-events | 1 + > hw/virtio/virtio-balloon.c | 59 +++++++++++++++++++ > include/hw/virtio/virtio-balloon.h | 2 +- > include/qemu/osdep.h | 7 +++ > .../standard-headers/linux/virtio_balloon.h | 1 + > 5 files changed, 69 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events > index e28ba48da6..f703a22d36 100644 > --- a/hw/virtio/trace-events > +++ b/hw/virtio/trace-events > @@ -46,6 +46,7 @@ virtio_balloon_handle_output(const char *name, uint64_t gpa) "section name: %s g > virtio_balloon_get_config(uint32_t num_pages, uint32_t actual) "num_pages: %d actual: %d" > virtio_balloon_set_config(uint32_t actual, uint32_t oldactual) "actual: %d oldactual: %d" > virtio_balloon_to_target(uint64_t target, uint32_t num_pages) "balloon target: 0x%"PRIx64" num_pages: %d" > +virtio_balloon_hinting_request(unsigned long pfn, unsigned int num_pages) "Guest page hinting request PFN:%lu size: %d" > > # virtio-mmio.c > virtio_mmio_read(uint64_t offset) "virtio_mmio_read offset 0x%" PRIx64 > diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c > index 2112874055..5d186707b5 100644 > --- a/hw/virtio/virtio-balloon.c > +++ b/hw/virtio/virtio-balloon.c > @@ -34,6 +34,9 @@ > > #define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT) > > +#define VIRTIO_BALLOON_PAGE_HINTING_MAX_PAGES 16 > +void free_mem_range(uint64_t addr, uint64_t len); > + > struct PartiallyBalloonedPage { > RAMBlock *rb; > ram_addr_t base; > @@ -328,6 +331,58 @@ static void balloon_stats_set_poll_interval(Object *obj, Visitor *v, > balloon_stats_change_timer(s, 0); > } > > +void free_mem_range(uint64_t addr, uint64_t len) > +{ > + int ret = 0; > + void *hvaddr_to_free; > + MemoryRegionSection mrs = memory_region_find(get_system_memory(), > + addr, 1); > + if (!mrs.mr) { > + warn_report("%s:No memory is mapped at address 0x%lu", __func__, addr); > + return; > + } > + > + if (!memory_region_is_ram(mrs.mr) && !memory_region_is_romd(mrs.mr)) { > + warn_report("%s:Memory at address 0x%s is not RAM:0x%lu", __func__, > + HWADDR_PRIx, addr); > + memory_region_unref(mrs.mr); > + return; > + } > + > + hvaddr_to_free = qemu_map_ram_ptr(mrs.mr->ram_block, mrs.offset_within_region); > + trace_virtio_balloon_hinting_request(addr, len); > + ret = qemu_madvise(hvaddr_to_free,len, QEMU_MADV_FREE); > + if (ret == -1) { > + warn_report("%s: Madvise failed with error:%d", __func__, ret); > + } > +} > + > +static void virtio_balloon_handle_page_hinting(VirtIODevice *vdev, > + VirtQueue *vq) > +{ > + VirtQueueElement *elem; > + size_t offset = 0; > + uint64_t gpa, len; > + elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); > + if (!elem) { > + return; > + } > + /* For pending hints which are < max_pages(16), 'gpa != 0' ensures that we > + * only read the buffer which holds a valid PFN value. > + * TODO: Find a better way to do this. Indeed. In fact, what is wrong with passing the gpa as part of the element itself? > + */ > + while (iov_to_buf(elem->out_sg, elem->out_num, offset, &gpa, 8) == 8 && gpa != 0) { > + offset += 8; > + offset += iov_to_buf(elem->out_sg, elem->out_num, offset, &len, 8); > + if (!qemu_balloon_is_inhibited()) { > + free_mem_range(gpa, len); > + } > + } > + virtqueue_push(vq, elem, offset); > + virtio_notify(vdev, vq); > + g_free(elem); > +} > + > static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) > { > VirtIOBalloon *s = VIRTIO_BALLOON(vdev); > @@ -694,6 +749,7 @@ 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); > + virtio_add_feature(&f, VIRTIO_BALLOON_F_HINTING); > > return f; > } > @@ -780,6 +836,7 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) > s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); > s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output); > s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats); > + s->hvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_page_hinting); > > if (virtio_has_feature(s->host_features, > VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { > @@ -875,6 +932,8 @@ static void virtio_balloon_instance_init(Object *obj) > > object_property_add(obj, "guest-stats", "guest statistics", > balloon_stats_get_all, NULL, NULL, s, NULL); > + object_property_add(obj, "guest-page-hinting", "guest page hinting", > + NULL, NULL, NULL, s, NULL); > > object_property_add(obj, "guest-stats-polling-interval", "int", > balloon_stats_get_poll_interval, > diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h > index 1afafb12f6..a58b24fdf2 100644 > --- a/include/hw/virtio/virtio-balloon.h > +++ b/include/hw/virtio/virtio-balloon.h > @@ -44,7 +44,7 @@ enum virtio_balloon_free_page_report_status { > > typedef struct VirtIOBalloon { > VirtIODevice parent_obj; > - VirtQueue *ivq, *dvq, *svq, *free_page_vq; > + VirtQueue *ivq, *dvq, *svq, *free_page_vq, *hvq; > uint32_t free_page_report_status; > uint32_t num_pages; > uint32_t actual; > diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > index af2b91f0b8..bb9207e7f4 100644 > --- a/include/qemu/osdep.h > +++ b/include/qemu/osdep.h > @@ -360,6 +360,11 @@ void qemu_anon_ram_free(void *ptr, size_t size); > #else > #define QEMU_MADV_REMOVE QEMU_MADV_INVALID > #endif > +#ifdef MADV_FREE > +#define QEMU_MADV_FREE MADV_FREE > +#else > +#define QEMU_MADV_FREE QEMU_MADV_INVALID > +#endif > > #elif defined(CONFIG_POSIX_MADVISE) > > @@ -373,6 +378,7 @@ void qemu_anon_ram_free(void *ptr, size_t size); > #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID > #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID > #define QEMU_MADV_REMOVE QEMU_MADV_INVALID > +#define QEMU_MADV_FREE QEMU_MADV_INVALID > > #else /* no-op */ > > @@ -386,6 +392,7 @@ void qemu_anon_ram_free(void *ptr, size_t size); > #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID > #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID > #define QEMU_MADV_REMOVE QEMU_MADV_INVALID > +#define QEMU_MADV_FREE QEMU_MADV_INVALID > > #endif > > diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h > index 9375ca2a70..f9e3e82562 100644 > --- a/include/standard-headers/linux/virtio_balloon.h > +++ b/include/standard-headers/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_HINTING 5 /* Page hinting virtqueue */ > > /* Size of a PFN in the balloon interface. */ > #define VIRTIO_BALLOON_PFN_SHIFT 12 > -- > 2.21.0