72f293de3f
An I/O request of a User VM, which is constructed by the hypervisor, is distributed by the ACRN Hypervisor Service Module to an I/O client corresponding to the address range of the I/O request. For each User VM, there is a shared 4-KByte memory region used for I/O requests communication between the hypervisor and Service VM. An I/O request is a 256-byte structure buffer, which is 'struct acrn_io_request', that is filled by an I/O handler of the hypervisor when a trapped I/O access happens in a User VM. ACRN userspace in the Service VM first allocates a 4-KByte page and passes the GPA (Guest Physical Address) of the buffer to the hypervisor. The buffer is used as an array of 16 I/O request slots with each I/O request slot being 256 bytes. This array is indexed by vCPU ID. An I/O client, which is 'struct acrn_ioreq_client', is responsible for handling User VM I/O requests whose accessed GPA falls in a certain range. Multiple I/O clients can be associated with each User VM. There is a special client associated with each User VM, called the default client, that handles all I/O requests that do not fit into the range of any other I/O clients. The ACRN userspace acts as the default client for each User VM. The state transitions of a ACRN I/O request are as follows. FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ... FREE: this I/O request slot is empty PENDING: a valid I/O request is pending in this slot PROCESSING: the I/O request is being processed COMPLETE: the I/O request has been processed An I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM and ACRN userspace are in charge of processing the others. The processing flow of I/O requests are listed as following: a) The I/O handler of the hypervisor will fill an I/O request with PENDING state when a trapped I/O access happens in a User VM. b) The hypervisor makes an upcall, which is a notification interrupt, to the Service VM. c) The upcall handler schedules a worker to dispatch I/O requests. d) The worker looks for the PENDING I/O requests, assigns them to different registered clients based on the address of the I/O accesses, updates their state to PROCESSING, and notifies the corresponding client to handle. e) The notified client handles the assigned I/O requests. f) The HSM updates I/O requests states to COMPLETE and notifies the hypervisor of the completion via hypercalls. Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Zhi Wang <zhi.a.wang@intel.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Yu Wang <yu1.wang@intel.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Shuo Liu <shuo.a.liu@intel.com> Link: https://lore.kernel.org/r/20210207031040.49576-10-shuo.a.liu@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ACRN_HSM: Virtual Machine management
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*
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* Copyright (C) 2020 Intel Corporation. All rights reserved.
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*
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* Authors:
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* Jason Chen CJ <jason.cj.chen@intel.com>
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* Yakui Zhao <yakui.zhao@intel.com>
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*/
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#include <linux/io.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include "acrn_drv.h"
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/* List of VMs */
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LIST_HEAD(acrn_vm_list);
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/*
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* acrn_vm_list is read in a worker thread which dispatch I/O requests and
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* is wrote in VM creation ioctl. Use the rwlock mechanism to protect it.
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*/
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DEFINE_RWLOCK(acrn_vm_list_lock);
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struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
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struct acrn_vm_creation *vm_param)
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{
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int ret;
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ret = hcall_create_vm(virt_to_phys(vm_param));
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if (ret < 0 || vm_param->vmid == ACRN_INVALID_VMID) {
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dev_err(acrn_dev.this_device,
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"Failed to create VM! Error: %d\n", ret);
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return NULL;
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}
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mutex_init(&vm->regions_mapping_lock);
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INIT_LIST_HEAD(&vm->ioreq_clients);
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spin_lock_init(&vm->ioreq_clients_lock);
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vm->vmid = vm_param->vmid;
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vm->vcpu_num = vm_param->vcpu_num;
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if (acrn_ioreq_init(vm, vm_param->ioreq_buf) < 0) {
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hcall_destroy_vm(vm_param->vmid);
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vm->vmid = ACRN_INVALID_VMID;
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return NULL;
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}
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write_lock_bh(&acrn_vm_list_lock);
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list_add(&vm->list, &acrn_vm_list);
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write_unlock_bh(&acrn_vm_list_lock);
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dev_dbg(acrn_dev.this_device, "VM %u created.\n", vm->vmid);
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return vm;
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}
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int acrn_vm_destroy(struct acrn_vm *vm)
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{
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int ret;
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if (vm->vmid == ACRN_INVALID_VMID ||
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test_and_set_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags))
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return 0;
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/* Remove from global VM list */
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write_lock_bh(&acrn_vm_list_lock);
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list_del_init(&vm->list);
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write_unlock_bh(&acrn_vm_list_lock);
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acrn_ioreq_deinit(vm);
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ret = hcall_destroy_vm(vm->vmid);
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if (ret < 0) {
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dev_err(acrn_dev.this_device,
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"Failed to destroy VM %u\n", vm->vmid);
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clear_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags);
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return ret;
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}
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acrn_vm_all_ram_unmap(vm);
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dev_dbg(acrn_dev.this_device, "VM %u destroyed.\n", vm->vmid);
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vm->vmid = ACRN_INVALID_VMID;
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return 0;
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}
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