From patchwork Mon Jul 10 09:20:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudio Imbrenda X-Patchwork-Id: 9832625 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 01FF960363 for ; Mon, 10 Jul 2017 09:21:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ECD5122376 for ; Mon, 10 Jul 2017 09:21:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E16A62842B; Mon, 10 Jul 2017 09:21:30 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 8BC1422376 for ; Mon, 10 Jul 2017 09:21:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753813AbdGJJV3 (ORCPT ); Mon, 10 Jul 2017 05:21:29 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:52100 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753506AbdGJJUw (ORCPT ); Mon, 10 Jul 2017 05:20:52 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6A9J0T3019469 for ; Mon, 10 Jul 2017 05:20:51 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bjux45wd4-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 10 Jul 2017 05:20:50 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 10 Jul 2017 10:20:47 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6A9Kkdc36372486; Mon, 10 Jul 2017 09:20:46 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C18CC5203F; Mon, 10 Jul 2017 09:17:07 +0100 (BST) Received: from p-imbrenda.boeblingen.de.ibm.com (unknown [9.152.224.193]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id 9CC7F52045; Mon, 10 Jul 2017 09:17:07 +0100 (BST) From: Claudio Imbrenda To: kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, pbonzini@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/1] KVM: trigger uevents when starting or stopping a VM Date: Mon, 10 Jul 2017 11:20:44 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1499678444-21879-1-git-send-email-imbrenda@linux.vnet.ibm.com> References: <1499678444-21879-1-git-send-email-imbrenda@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17071009-0040-0000-0000-000003DF7D53 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17071009-0041-0000-0000-0000207A2397 Message-Id: <1499678444-21879-2-git-send-email-imbrenda@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-07-10_04:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1707100167 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds a few lines to the KVM common code to fire a KOBJ_CHANGE uevent whenever a KVM VM is created or destroyed. The event carries five environment variables: CREATED indicates how many times a new VM has been created. It is useful for example to trigger specific actions when the first VM is started COUNT indicates how many VMs are currently active. This can be used for logging or monitoring purposes PID has the pid of the KVM process that has been started or stopped. This can be used to perform process-specific tuning. STATS_PATH contains the path in debugfs to the directory with all the runtime statistics for this VM. This is useful for performance monitoring and profiling. EVENT described the type of event, its value can be either "create" or "destroy" Specific udev rules can be then set up in userspace to deal with the creation or destruction of VMs as needed. Signed-off-by: Claudio Imbrenda --- virt/kvm/kvm_main.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f0fe9d0..7c39783 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -130,6 +130,12 @@ EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; +#define KVM_EVENT_CREATE_VM 0 +#define KVM_EVENT_DESTROY_VM 1 +static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm); +static unsigned long long kvm_createvm_count; +static unsigned long long kvm_active_vms; + bool kvm_is_reserved_pfn(kvm_pfn_t pfn) { if (pfn_valid(pfn)) @@ -728,6 +734,7 @@ static void kvm_destroy_vm(struct kvm *kvm) int i; struct mm_struct *mm = kvm->mm; + kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); spin_lock(&kvm_lock); @@ -3196,6 +3203,7 @@ static int kvm_dev_ioctl_create_vm(unsigned long type) fput(file); return -ENOMEM; } + kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm); fd_install(r, file); return r; @@ -3848,6 +3856,57 @@ static const struct file_operations *stat_fops[] = { [KVM_STAT_VM] = &vm_stat_fops, }; +static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) +{ + char cbuf[32], abuf[32], pidbuf[32], evbuf[16]; + const char pathvar[11] = "STATS_PATH="; + char *ptr[6] = {cbuf, abuf, pidbuf, NULL, NULL, NULL}; + char *tmp, *pathbuf; + unsigned long long created, active; + int idx = 3; + + if (!kvm_dev.this_device || !kvm || !kvm->debugfs_dentry) + return; + + spin_lock(&kvm_lock); + if (type == KVM_EVENT_CREATE_VM) { + kvm_createvm_count++; + kvm_active_vms++; + } else if (type == KVM_EVENT_DESTROY_VM) { + kvm_active_vms--; + } + created = kvm_createvm_count; + active = kvm_active_vms; + spin_unlock(&kvm_lock); + + pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); + if (pathbuf) { + tmp = dentry_path_raw(kvm->debugfs_dentry, + pathbuf + sizeof(pathvar), + PATH_MAX - sizeof(pathvar)); + if (!IS_ERR(tmp)) { + memcpy(tmp - sizeof(pathvar), pathvar, sizeof(pathvar)); + ptr[idx++] = tmp - sizeof(pathvar); + } + } + snprintf(cbuf, sizeof(cbuf), "CREATED=%llu", created); + snprintf(abuf, sizeof(abuf), "COUNT=%llu", active); + snprintf(pidbuf, sizeof(pidbuf), "PID=%s", + kvm->debugfs_dentry->d_name.name); + tmp = strchr(pidbuf, '-'); + if (tmp) + *tmp = '\0'; + if (type == KVM_EVENT_CREATE_VM) { + snprintf(evbuf, sizeof(evbuf), "EVENT=create"); + ptr[idx++] = evbuf; + } else if (type == KVM_EVENT_DESTROY_VM) { + snprintf(evbuf, sizeof(evbuf), "EVENT=destroy"); + ptr[idx++] = evbuf; + } + kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, ptr); + kfree(pathbuf); +} + static int kvm_init_debug(void) { int r = -EEXIST;