From patchwork Tue May 9 20:47:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 680259 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA989C7EE24 for ; Tue, 9 May 2023 20:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235623AbjEIUvo (ORCPT ); Tue, 9 May 2023 16:51:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235509AbjEIUvO (ORCPT ); Tue, 9 May 2023 16:51:14 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40C8B7698; Tue, 9 May 2023 13:49:56 -0700 (PDT) Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 349JAibt025841; Tue, 9 May 2023 20:49:19 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=nWf+ZSuj71HDMbzYLsweKAvZBl3br9uyehH93SKwObM=; b=n8mxaJKnphXjtyQp2nHenHEiFx3sNxFi3VSogsxmG3KocPhC0BBc3RWm6aA/VZRxpRXL XABThTI7B8lJuUM4LjZb2Nt7GaWPnXOaNoGYvMCGGzmTI2RAoe0BE5xXIo24fGJXs33q EdsRFzM52ANvdZ76IOUBC0WP7+LALeX72n43gPpqIEDn2j+DE0CaKy56Z4/YbJWtYuH3 uAq0FEmUkFOMQ57K/pQpv0UmbJscC9pTxmRbdl6L1d4ts2R88/dUkard8r8V/LIkpDEr blwSCAYPr378inl9zYUjGuEJFC7Uwu9Evb+IL8nU10NDj8YqunLERinG1GesEzLANoIT gw== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qfsxj8f04-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 May 2023 20:49:18 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 349KnIVE014196 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 9 May 2023 20:49:18 GMT Received: from hu-eberman-lv.qualcomm.com (10.49.16.6) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 9 May 2023 13:49:17 -0700 From: Elliot Berman To: Alex Elder , Srinivas Kandagatla , Elliot Berman , Prakruthi Deepak Heragu , Jonathan Corbet CC: Murali Nalajala , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Dmitry Baryshkov , Bjorn Andersson , "Konrad Dybcio" , Arnd Bergmann , "Greg Kroah-Hartman" , Rob Herring , Krzysztof Kozlowski , Bagas Sanjaya , Will Deacon , Andy Gross , Catalin Marinas , Jassi Brar , , , , , Subject: [PATCH v13 17/24] gunyah: vm_mgr: Add framework for VM Functions Date: Tue, 9 May 2023 13:47:54 -0700 Message-ID: <20230509204801.2824351-18-quic_eberman@quicinc.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230509204801.2824351-1-quic_eberman@quicinc.com> References: <20230509204801.2824351-1-quic_eberman@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: Kw8re2-78R97iVO_ZJ_4F7XsNo5ChfjU X-Proofpoint-GUID: Kw8re2-78R97iVO_ZJ_4F7XsNo5ChfjU X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-09_13,2023-05-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 phishscore=0 spamscore=0 suspectscore=0 clxscore=1015 impostorscore=0 bulkscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2305090171 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Introduce a framework for Gunyah userspace to install VM functions. VM functions are optional interfaces to the virtual machine. vCPUs, ioeventfs, and irqfds are examples of such VM functions and are implemented in subsequent patches. A generic framework is implemented instead of individual ioctls to create vCPUs, irqfds, etc., in order to simplify the VM manager core implementation and allow dynamic loading of VM function modules. Signed-off-by: Elliot Berman Reviewed-by: Alex Elder --- Documentation/virt/gunyah/vm-manager.rst | 18 ++ drivers/virt/gunyah/vm_mgr.c | 216 ++++++++++++++++++++++- drivers/virt/gunyah/vm_mgr.h | 4 + include/linux/gunyah_vm_mgr.h | 87 +++++++++ include/uapi/linux/gunyah.h | 18 ++ 5 files changed, 340 insertions(+), 3 deletions(-) create mode 100644 include/linux/gunyah_vm_mgr.h diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst index 50d8ae7fabcd..3b51bab9d793 100644 --- a/Documentation/virt/gunyah/vm-manager.rst +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -17,6 +17,24 @@ sharing userspace memory with a VM is done via the `GH_VM_SET_USER_MEM_REGION`_ ioctl. The VM itself is configured to use the memory region via the devicetree. +Gunyah Functions +================ + +Components of a Gunyah VM's configuration that need kernel configuration are +called "functions" and are built on top of a framework. Functions are identified +by a string and have some argument(s) to configure them. They are typically +created by the `GH_VM_ADD_FUNCTION`_ ioctl. + +Functions typically will always do at least one of these operations: + +1. Create resource ticket(s). Resource tickets allow a function to register + itself as the client for a Gunyah resource (e.g. doorbell or vCPU) and + the function is given the pointer to the &struct gh_resource when the + VM is starting. + +2. Register IO handler(s). IO handlers allow a function to handle stage-2 faults + from the virtual machine. + Sample Userspace VMM ==================== diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c index a800061f56bf..56464451b262 100644 --- a/drivers/virt/gunyah/vm_mgr.c +++ b/drivers/virt/gunyah/vm_mgr.c @@ -6,10 +6,13 @@ #define pr_fmt(fmt) "gh_vm_mgr: " fmt #include +#include #include #include +#include #include #include +#include #include @@ -17,6 +20,172 @@ static void gh_vm_free(struct work_struct *work); +static DEFINE_XARRAY(gh_vm_functions); + +static void gh_vm_put_function(struct gh_vm_function *fn) +{ + module_put(fn->mod); +} + +static struct gh_vm_function *gh_vm_get_function(u32 type) +{ + struct gh_vm_function *fn; + int r; + + fn = xa_load(&gh_vm_functions, type); + if (!fn) { + r = request_module("ghfunc:%d", type); + if (r) + return ERR_PTR(r > 0 ? -r : r); + + fn = xa_load(&gh_vm_functions, type); + } + + if (!fn || !try_module_get(fn->mod)) + fn = ERR_PTR(-ENOENT); + + return fn; +} + +static void gh_vm_remove_function_instance(struct gh_vm_function_instance *inst) + __must_hold(&inst->ghvm->fn_lock) +{ + inst->fn->unbind(inst); + list_del(&inst->vm_list); + gh_vm_put_function(inst->fn); + kfree(inst->argp); + kfree(inst); +} + +static void gh_vm_remove_functions(struct gh_vm *ghvm) +{ + struct gh_vm_function_instance *inst, *iiter; + + mutex_lock(&ghvm->fn_lock); + list_for_each_entry_safe(inst, iiter, &ghvm->functions, vm_list) { + gh_vm_remove_function_instance(inst); + } + mutex_unlock(&ghvm->fn_lock); +} + +static long gh_vm_add_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f) +{ + struct gh_vm_function_instance *inst; + void __user *argp; + long r = 0; + + if (f->arg_size > GH_FN_MAX_ARG_SIZE) { + dev_err_ratelimited(ghvm->parent, "%s: arg_size > %d\n", + __func__, GH_FN_MAX_ARG_SIZE); + return -EINVAL; + } + + inst = kzalloc(sizeof(*inst), GFP_KERNEL); + if (!inst) + return -ENOMEM; + + inst->arg_size = f->arg_size; + if (inst->arg_size) { + inst->argp = kzalloc(inst->arg_size, GFP_KERNEL); + if (!inst->argp) { + r = -ENOMEM; + goto free; + } + + argp = u64_to_user_ptr(f->arg); + if (copy_from_user(inst->argp, argp, f->arg_size)) { + r = -EFAULT; + goto free_arg; + } + } + + inst->fn = gh_vm_get_function(f->type); + if (IS_ERR(inst->fn)) { + r = PTR_ERR(inst->fn); + goto free_arg; + } + + inst->ghvm = ghvm; + inst->rm = ghvm->rm; + + mutex_lock(&ghvm->fn_lock); + r = inst->fn->bind(inst); + if (r < 0) { + mutex_unlock(&ghvm->fn_lock); + gh_vm_put_function(inst->fn); + goto free_arg; + } + + list_add(&inst->vm_list, &ghvm->functions); + mutex_unlock(&ghvm->fn_lock); + + return r; +free_arg: + kfree(inst->argp); +free: + kfree(inst); + return r; +} + +static long gh_vm_rm_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f) +{ + struct gh_vm_function_instance *inst, *iter; + void __user *user_argp; + void *argp; + long r = 0; + + r = mutex_lock_interruptible(&ghvm->fn_lock); + if (r) + return r; + + if (f->arg_size) { + argp = kzalloc(f->arg_size, GFP_KERNEL); + if (!argp) { + r = -ENOMEM; + goto out; + } + + user_argp = u64_to_user_ptr(f->arg); + if (copy_from_user(argp, user_argp, f->arg_size)) { + r = -EFAULT; + kfree(argp); + goto out; + } + + r = -ENOENT; + list_for_each_entry_safe(inst, iter, &ghvm->functions, vm_list) { + if (inst->fn->type == f->type && + inst->fn->compare(inst, argp, f->arg_size)) { + gh_vm_remove_function_instance(inst); + r = 0; + } + } + + kfree(argp); + } + +out: + mutex_unlock(&ghvm->fn_lock); + return r; +} + +int gh_vm_function_register(struct gh_vm_function *fn) +{ + if (!fn->bind || !fn->unbind) + return -EINVAL; + + return xa_err(xa_store(&gh_vm_functions, fn->type, fn, GFP_KERNEL)); +} +EXPORT_SYMBOL_GPL(gh_vm_function_register); + +void gh_vm_function_unregister(struct gh_vm_function *fn) +{ + /* Expecting unregister to only come when unloading a module */ + WARN_ON(fn->mod && module_refcount(fn->mod)); + xa_erase(&gh_vm_functions, fn->type); +} +EXPORT_SYMBOL_GPL(gh_vm_function_unregister); + static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data) { struct gh_rm_vm_status_payload *payload = data; @@ -98,6 +267,8 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm) init_rwsem(&ghvm->status_lock); init_waitqueue_head(&ghvm->vm_status_wait); INIT_WORK(&ghvm->free_work, gh_vm_free); + kref_init(&ghvm->kref); + INIT_LIST_HEAD(&ghvm->functions); ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE; return ghvm; @@ -254,6 +425,24 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) r = gh_vm_ensure_started(ghvm); break; } + case GH_VM_ADD_FUNCTION: { + struct gh_fn_desc f; + + if (copy_from_user(&f, argp, sizeof(f))) + return -EFAULT; + + r = gh_vm_add_function_instance(ghvm, &f); + break; + } + case GH_VM_REMOVE_FUNCTION: { + struct gh_fn_desc f; + + if (copy_from_user(&f, argp, sizeof(f))) + return -EFAULT; + + r = gh_vm_rm_function_instance(ghvm, &f); + break; + } default: r = -ENOTTY; break; @@ -270,6 +459,8 @@ static void gh_vm_free(struct work_struct *work) if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING) gh_vm_stop(ghvm); + gh_vm_remove_functions(ghvm); + if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE && ghvm->vm_status != GH_RM_VM_STATUS_LOAD && ghvm->vm_status != GH_RM_VM_STATUS_RESET) { @@ -294,14 +485,33 @@ static void gh_vm_free(struct work_struct *work) kfree(ghvm); } -static int gh_vm_release(struct inode *inode, struct file *filp) +int __must_check gh_vm_get(struct gh_vm *ghvm) { - struct gh_vm *ghvm = filp->private_data; + return kref_get_unless_zero(&ghvm->kref); +} +EXPORT_SYMBOL_GPL(gh_vm_get); + +static void _gh_vm_put(struct kref *kref) +{ + struct gh_vm *ghvm = container_of(kref, struct gh_vm, kref); /* VM will be reset and make RM calls which can interruptible sleep. * Defer to a work so this thread can receive signal. */ schedule_work(&ghvm->free_work); +} + +void gh_vm_put(struct gh_vm *ghvm) +{ + kref_put(&ghvm->kref, _gh_vm_put); +} +EXPORT_SYMBOL_GPL(gh_vm_put); + +static int gh_vm_release(struct inode *inode, struct file *filp) +{ + struct gh_vm *ghvm = filp->private_data; + + gh_vm_put(ghvm); return 0; } @@ -346,7 +556,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg) err_put_fd: put_unused_fd(fd); err_destroy_vm: - gh_vm_free(&ghvm->free_work); + gh_vm_put(ghvm); return err; } diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h index 4173bd51f83f..c4bec1469ae8 100644 --- a/drivers/virt/gunyah/vm_mgr.h +++ b/drivers/virt/gunyah/vm_mgr.h @@ -8,6 +8,7 @@ #include #include +#include #include #include #include @@ -45,9 +46,12 @@ struct gh_vm { struct rw_semaphore status_lock; struct work_struct free_work; + struct kref kref; struct mm_struct *mm; /* userspace tied to this vm */ struct mutex mm_lock; struct list_head memory_mappings; + struct mutex fn_lock; + struct list_head functions; }; int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region); diff --git a/include/linux/gunyah_vm_mgr.h b/include/linux/gunyah_vm_mgr.h new file mode 100644 index 000000000000..1f0dc43ade50 --- /dev/null +++ b/include/linux/gunyah_vm_mgr.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#ifndef _GUNYAH_VM_MGR_H +#define _GUNYAH_VM_MGR_H + +#include +#include +#include +#include +#include +#include + +#include + +struct gh_vm; + +int __must_check gh_vm_get(struct gh_vm *ghvm); +void gh_vm_put(struct gh_vm *ghvm); + +struct gh_vm_function_instance; +struct gh_vm_function { + u32 type; + const char *name; + struct module *mod; + long (*bind)(struct gh_vm_function_instance *f); + void (*unbind)(struct gh_vm_function_instance *f); + bool (*compare)(const struct gh_vm_function_instance *f, const void *arg, size_t size); +}; + +/** + * struct gh_vm_function_instance - Represents one function instance + * @arg_size: size of user argument + * @argp: pointer to user argument + * @ghvm: Pointer to VM instance + * @rm: Pointer to resource manager for the VM instance + * @fn: The ops for the function + * @data: Private data for function + * @vm_list: for gh_vm's functions list + * @fn_list: for gh_vm_function's instances list + */ +struct gh_vm_function_instance { + size_t arg_size; + void *argp; + struct gh_vm *ghvm; + struct gh_rm *rm; + struct gh_vm_function *fn; + void *data; + struct list_head vm_list; +}; + +int gh_vm_function_register(struct gh_vm_function *f); +void gh_vm_function_unregister(struct gh_vm_function *f); + +/* Since the function identifiers were setup in a uapi header as an + * enum and we do no want to change that, the user must supply the expanded + * constant as well and the compiler checks they are the same. + * See also MODULE_ALIAS_RDMA_NETLINK. + */ +#define MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx) \ + static inline void __maybe_unused __chk##_idx(void) \ + { \ + BUILD_BUG_ON(_type != _idx); \ + } \ + MODULE_ALIAS("ghfunc:" __stringify(_idx)) + +#define DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare) \ + static struct gh_vm_function _name = { \ + .type = _type, \ + .name = __stringify(_name), \ + .mod = THIS_MODULE, \ + .bind = _bind, \ + .unbind = _unbind, \ + .compare = _compare, \ + } + +#define module_gh_vm_function(__gf) \ + module_driver(__gf, gh_vm_function_register, gh_vm_function_unregister) + +#define DECLARE_GH_VM_FUNCTION_INIT(_name, _type, _idx, _bind, _unbind, _compare) \ + DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare); \ + module_gh_vm_function(_name); \ + MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx) + +#endif diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index 4b63d0b9b8ba..bb07118a351f 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -72,4 +72,22 @@ struct gh_vm_dtb_config { #define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3) +#define GH_FN_MAX_ARG_SIZE 256 + +/** + * struct gh_fn_desc - Arguments to create a VM function + * @type: Type of the function. See &enum gh_fn_type. + * @arg_size: Size of argument to pass to the function. arg_size <= GH_FN_MAX_ARG_SIZE + * @arg: Pointer to argument given to the function. See &enum gh_fn_type for expected + * arguments for a function type. + */ +struct gh_fn_desc { + __u32 type; + __u32 arg_size; + __u64 arg; +}; + +#define GH_VM_ADD_FUNCTION _IOW(GH_IOCTL_TYPE, 0x4, struct gh_fn_desc) +#define GH_VM_REMOVE_FUNCTION _IOW(GH_IOCTL_TYPE, 0x7, struct gh_fn_desc) + #endif