From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 81F866B000E for ; Fri, 15 Jun 2018 01:08:47 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id n19-v6so4098668pff.8 for ; Thu, 14 Jun 2018 22:08:47 -0700 (PDT) Received: from mga12.intel.com (mga12.intel.com. [192.55.52.136]) by mx.google.com with ESMTPS id m89-v6si6984006pfi.236.2018.06.14.22.08.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jun 2018 22:08:46 -0700 (PDT) From: Wei Wang Subject: [PATCH v33 4/4] virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON Date: Fri, 15 Jun 2018 12:43:13 +0800 Message-Id: <1529037793-35521-5-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, pbonzini@redhat.com, wei.w.wang@intel.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, peterx@redhat.com The VIRTIO_BALLOON_F_PAGE_POISON feature bit is used to indicate if the guest is using page poisoning. Guest writes to the poison_val config field to tell host about the page poisoning value that is in use. Suggested-by: Michael S. Tsirkin Signed-off-by: Wei Wang Cc: Michael S. Tsirkin Cc: Michal Hocko Cc: Andrew Morton --- drivers/virtio/virtio_balloon.c | 10 ++++++++++ include/uapi/linux/virtio_balloon.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 582a03b..c59bb380 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -634,6 +634,7 @@ static struct file_system_type balloon_fs = { static int virtballoon_probe(struct virtio_device *vdev) { struct virtio_balloon *vb; + __u32 poison_val; int err; if (!vdev->config->get) { @@ -671,6 +672,11 @@ static int virtballoon_probe(struct virtio_device *vdev) goto out_del_vqs; } INIT_WORK(&vb->report_free_page_work, report_free_page_func); + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + memset(&poison_val, PAGE_POISON, sizeof(poison_val)); + virtio_cwrite(vb->vdev, struct virtio_balloon_config, + poison_val, &poison_val); + } vb->hints = kmalloc(FREE_PAGE_HINT_MEM_SIZE, GFP_KERNEL); if (!vb->hints) { err = -ENOMEM; @@ -796,6 +802,9 @@ static int virtballoon_restore(struct virtio_device *vdev) static int virtballoon_validate(struct virtio_device *vdev) { + if (!page_poisoning_enabled()) + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON); + __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM); return 0; } @@ -805,6 +814,7 @@ static unsigned int features[] = { VIRTIO_BALLOON_F_STATS_VQ, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_FREE_PAGE_HINT, + VIRTIO_BALLOON_F_PAGE_POISON, }; static struct virtio_driver virtio_balloon_driver = { diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 99b8416..f3b6191 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_FREE_PAGE_HINT 3 /* VQ to report free pages */ +#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 @@ -47,6 +48,8 @@ struct virtio_balloon_config { __u32 actual; /* Command sent from host */ __u32 host_cmd; + /* Stores PAGE_POISON if page poisoning is in use */ + __u32 poison_val; }; struct virtio_balloon_free_page_hints { -- 2.7.4