From patchwork Mon Jun 11 15:19:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nitesh Lal X-Patchwork-Id: 10458401 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 98F2B6020F for ; Mon, 11 Jun 2018 15:19:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 89901284FF for ; Mon, 11 Jun 2018 15:19:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7C6D328501; Mon, 11 Jun 2018 15:19:20 +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 vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE1B6284FF for ; Mon, 11 Jun 2018 15:19:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932932AbeFKPTR (ORCPT ); Mon, 11 Jun 2018 11:19:17 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34140 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932924AbeFKPTQ (ORCPT ); Mon, 11 Jun 2018 11:19:16 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 97F8940711F3; Mon, 11 Jun 2018 15:19:15 +0000 (UTC) Received: from Dungeon.bos.redhat.com (dhcp-17-200.bos.redhat.com [10.18.17.200]) by smtp.corp.redhat.com (Postfix) with ESMTP id 148E28443C; Mon, 11 Jun 2018 15:19:15 +0000 (UTC) From: nilal@redhat.com To: kvm@vger.kernel.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, mst@redhat.com, dodgen@google.com, konrad.wilk@oracle.com, dhildenb@redhat.com Subject: [RFC][Patch V7 6/7] KVM: Enabling guest page hinting via static key Date: Mon, 11 Jun 2018 11:19:01 -0400 Message-Id: <20180611151902.14383-7-nilal@redhat.com> In-Reply-To: <20180611151902.14383-1-nilal@redhat.com> References: <20180611151902.14383-1-nilal@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Mon, 11 Jun 2018 15:19:15 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Mon, 11 Jun 2018 15:19:15 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'nilal@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Nitesh Narayan Lal This patch enables the guest page hinting support to enable or disable based on the STATIC key which could be set via sysctl. Signed-off-by: Nitesh Narayan Lal --- drivers/virtio/virtio_balloon.c | 16 +++++++++++----- include/linux/gfp.h | 16 ++++++++++++++-- include/linux/page_hinting.h | 7 +++++++ kernel/sysctl.c | 9 +++++++++ virt/kvm/page_hinting.c | 29 +++++++++++++++++++++++++---- 5 files changed, 66 insertions(+), 11 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 217523f..a5cbcc9 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -32,7 +32,6 @@ #include #include #include -#include /* * Balloon device works in 4K page units. So each page is pointed to by @@ -124,6 +123,14 @@ static void hinting_ack(struct virtqueue *vq) wake_up(&vb->acked); } + +static void enable_hinting(struct virtio_balloon *vb) +{ + guest_page_hinting_flag = 1; + static_branch_enable(&guest_page_hinting_key); + request_hypercall = (void *)&virtballoon_page_hinting; + balloon_ptr = vb; +} #endif static u32 page_to_balloon_pfn(struct page *page) @@ -533,6 +540,7 @@ static int init_vqs(struct virtio_balloon *vb) if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { struct scatterlist sg; unsigned int num_stats; + vb->stats_vq = vqs[2]; /* @@ -694,10 +702,8 @@ static int virtballoon_probe(struct virtio_device *vdev) virtio_device_ready(vdev); #ifdef CONFIG_KVM_FREE_PAGE_HINTING - if (virtio_has_feature(vb->vdev, VIRTIO_GUEST_PAGE_HINTING_VQ)) { - request_hypercall = (void *)&virtballoon_page_hinting; - balloon_ptr = vb; - } + if (virtio_has_feature(vb->vdev, VIRTIO_GUEST_PAGE_HINTING_VQ)) + enable_hinting(vb); #endif if (towards_target(vb)) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 72cd41b..fbef049 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -7,6 +7,7 @@ #include #include #include +#include struct vm_area_struct; @@ -442,8 +443,19 @@ static inline struct zonelist *node_zonelist(int nid, gfp_t flags) #ifdef CONFIG_KVM_FREE_PAGE_HINTING #define HAVE_ARCH_ALLOC_PAGE #define HAVE_ARCH_FREE_PAGE -void arch_free_page(struct page *page, int order); -void arch_alloc_page(struct page *page, int order); +static inline void arch_alloc_page(struct page *page, int order) +{ + if (!static_branch_unlikely(&guest_page_hinting_key)) + return; + guest_alloc_page(page, order); +} + +static inline void arch_free_page(struct page *page, int order) +{ + if (!static_branch_unlikely(&guest_page_hinting_key)) + return; + guest_free_page(page, order); +} #endif #ifndef HAVE_ARCH_FREE_PAGE diff --git a/include/linux/page_hinting.h b/include/linux/page_hinting.h index 0bfb646..dd30644 100644 --- a/include/linux/page_hinting.h +++ b/include/linux/page_hinting.h @@ -14,3 +14,10 @@ struct hypervisor_pages { extern struct hypervisor_pages hypervisor_pagelist[MAX_FGPT_ENTRIES]; extern void (*request_hypercall)(void *, int); extern void *balloon_ptr; + +extern struct static_key_false guest_page_hinting_key; +int guest_page_hinting_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos); +extern int guest_page_hinting_flag; +void guest_alloc_page(struct page *page, int order); +void guest_free_page(struct page *page, int order); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6a78cf7..bfb963e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1661,6 +1661,15 @@ static struct ctl_table vm_table[] = { .extra2 = (void *)&mmap_rnd_compat_bits_max, }, #endif +#ifdef CONFIG_KVM_FREE_PAGE_HINTING + { + .procname = "guest-page-hinting", + .data = &guest_page_hinting_flag, + .maxlen = sizeof(guest_page_hinting_flag), + .mode = 0644, + .proc_handler = guest_page_hinting_sysctl, + }, +#endif { } }; diff --git a/virt/kvm/page_hinting.c b/virt/kvm/page_hinting.c index 417582a..078a3be 100644 --- a/virt/kvm/page_hinting.c +++ b/virt/kvm/page_hinting.c @@ -5,7 +5,6 @@ #include #include #include -#include #define HYPERLIST_THRESHOLD 1 /* FIXME: find a good threshold */ /* @@ -30,6 +29,29 @@ void (*request_hypercall)(void *, int); EXPORT_SYMBOL(request_hypercall); void *balloon_ptr; EXPORT_SYMBOL(balloon_ptr); +struct static_key_false guest_page_hinting_key = STATIC_KEY_FALSE_INIT; +EXPORT_SYMBOL(guest_page_hinting_key); +static DEFINE_MUTEX(hinting_mutex); +int guest_page_hinting_flag; +EXPORT_SYMBOL(guest_page_hinting_flag); + +int guest_page_hinting_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret; + + mutex_lock(&hinting_mutex); + + ret = proc_dointvec(table, write, buffer, lenp, ppos); + + if (guest_page_hinting_flag) + static_key_enable(&guest_page_hinting_key.key); + else + static_key_disable(&guest_page_hinting_key.key); + mutex_unlock(&hinting_mutex); + return ret; +} static void empty_hyperlist(void) { @@ -254,7 +276,7 @@ void arch_free_page_slowpath(void) write_sequnlock(&guest_page_lock); } -void arch_alloc_page(struct page *page, int order) +void guest_alloc_page(struct page *page, int order) { unsigned int seq; @@ -270,12 +292,11 @@ void arch_alloc_page(struct page *page, int order) trace_guest_alloc_page(page, order); } -void arch_free_page(struct page *page, int order) +void guest_free_page(struct page *page, int order) { int *free_page_idx = &get_cpu_var(kvm_pt_idx); struct kvm_free_pages *free_page_obj; unsigned long flags; - /* * use of global variables may trigger a race condition between irq and * process context causing unwanted overwrites. This will be replaced