From patchwork Wed Mar 20 08:37:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 10861059 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 D3DC415AC for ; Wed, 20 Mar 2019 08:47:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BB54B29AB7 for ; Wed, 20 Mar 2019 08:47:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AFEDF29AB8; Wed, 20 Mar 2019 08:47:14 +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 363D229AAC for ; Wed, 20 Mar 2019 08:47:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726780AbfCTIrN (ORCPT ); Wed, 20 Mar 2019 04:47:13 -0400 Received: from 7.mo7.mail-out.ovh.net ([46.105.43.131]:48694 "EHLO 7.mo7.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726065AbfCTIrN (ORCPT ); Wed, 20 Mar 2019 04:47:13 -0400 Received: from player787.ha.ovh.net (unknown [10.109.143.24]) by mo7.mail-out.ovh.net (Postfix) with ESMTP id E4E5110A685 for ; Wed, 20 Mar 2019 09:40:18 +0100 (CET) Received: from kaod.org (lfbn-1-2226-17.w90-76.abo.wanadoo.fr [90.76.48.17]) (Authenticated sender: clg@kaod.org) by player787.ha.ovh.net (Postfix) with ESMTPSA id B8FA53F3B72A; Wed, 20 Mar 2019 08:40:09 +0000 (UTC) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: kvm-ppc@vger.kernel.org Cc: Paul Mackerras , David Gibson , kvm@vger.kernel.org, Michael Ellerman , linuxppc-dev@lists.ozlabs.org, =?utf-8?q?C=C3=A9dric_Le_Goater?= , Paolo Bonzini Subject: [PATCH v4 16/17] KVM: introduce a KVM_DESTROY_DEVICE ioctl Date: Wed, 20 Mar 2019 09:37:50 +0100 Message-Id: <20190320083751.27001-17-clg@kaod.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190320083751.27001-1-clg@kaod.org> References: <20190320083751.27001-1-clg@kaod.org> MIME-Version: 1.0 X-Ovh-Tracer-Id: 18190601847763405783 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedutddrieehgdduvdeiucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddm Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The 'destroy' method is currently used to destroy all devices when the VM is destroyed after the vCPUs have been freed. This new KVM ioctl exposes the same KVM device method. It acts as a software reset of the VM to 'destroy' selected devices when necessary and perform the required cleanups on the vCPUs. Called with the kvm->lock. The 'destroy' method could be improved by returning an error code. Cc: Paolo Bonzini Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson --- Changes since v3 : - Removed temporary TODO comment in kvm_ioctl_destroy_device() regarding kvm_put_kvm() Changes since v2 : - checked that device is owned by VM include/uapi/linux/kvm.h | 7 ++++++ virt/kvm/kvm_main.c | 41 +++++++++++++++++++++++++++++++ Documentation/virtual/kvm/api.txt | 20 +++++++++++++++ 3 files changed, 68 insertions(+) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 52bf74a1616e..d78fafa54274 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1183,6 +1183,11 @@ struct kvm_create_device { __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ }; +struct kvm_destroy_device { + __u32 fd; /* in: device handle */ + __u32 flags; /* in: unused */ +}; + struct kvm_device_attr { __u32 flags; /* no flags currently defined */ __u32 group; /* device-defined */ @@ -1331,6 +1336,8 @@ struct kvm_s390_ucas_mapping { #define KVM_GET_DEVICE_ATTR _IOW(KVMIO, 0xe2, struct kvm_device_attr) #define KVM_HAS_DEVICE_ATTR _IOW(KVMIO, 0xe3, struct kvm_device_attr) +#define KVM_DESTROY_DEVICE _IOWR(KVMIO, 0xf0, struct kvm_destroy_device) + /* * ioctls for vcpu fds */ diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5e2fa5c7dd1a..9601c2ddecc5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3032,6 +3032,33 @@ static int kvm_ioctl_create_device(struct kvm *kvm, return 0; } +static int kvm_ioctl_destroy_device(struct kvm *kvm, + struct kvm_destroy_device *dd) +{ + struct fd f; + struct kvm_device *dev; + + f = fdget(dd->fd); + if (!f.file) + return -EBADF; + + dev = kvm_device_from_filp(f.file); + fdput(f); + + if (!dev) + return -ENODEV; + + if (dev->kvm != kvm) + return -EPERM; + + mutex_lock(&kvm->lock); + list_del(&dev->vm_node); + dev->ops->destroy(dev); + mutex_unlock(&kvm->lock); + + return 0; +} + static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) { switch (arg) { @@ -3276,6 +3303,20 @@ static long kvm_vm_ioctl(struct file *filp, r = 0; break; } + case KVM_DESTROY_DEVICE: { + struct kvm_destroy_device dd; + + r = -EFAULT; + if (copy_from_user(&dd, argp, sizeof(dd))) + goto out; + + r = kvm_ioctl_destroy_device(kvm, &dd); + if (r) + goto out; + + r = 0; + break; + } case KVM_CHECK_EXTENSION: r = kvm_vm_ioctl_check_extension_generic(kvm, arg); break; diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 8022ecce2c47..abe8433adf4f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3874,6 +3874,26 @@ number of valid entries in the 'entries' array, which is then filled. 'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, userspace should not expect to get any particular value there. +4.119 KVM_DESTROY_DEVICE + +Capability: KVM_CAP_DEVICE_CTRL +Type: vm ioctl +Parameters: struct kvm_destroy_device (in) +Returns: 0 on success, -1 on error +Errors: + ENODEV: The device type is unknown or unsupported + EPERM: The device does not belong to the VM + + Other error conditions may be defined by individual device types or + have their standard meanings. + +Destroys an emulated device in the kernel. + +struct kvm_destroy_device { + __u32 fd; /* in: device handle */ + __u32 flags; /* unused */ +}; + 5. The kvm_run structure ------------------------