mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

virt: acrn: Introduce I/O request management 

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>
This commit is contained in:
Shuo Liu 2021-02-07 11:10:31 +08:00 committed by Greg Kroah-Hartman
parent 88f537d5e8
commit 72f293de3f
7 changed files with 843 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/virt/acrn/Makefile
View File

@ -1,3 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ACRN_HSM) := acrn.o
acrn-y := hsm.o vm.o mm.o
acrn-y := hsm.o vm.o mm.o ioreq.o

82
drivers/virt/acrn/acrn_drv.h
View File

@ -12,10 +12,15 @@
extern struct miscdevice acrn_dev;
#define ACRN_NAME_LEN 16
#define ACRN_MEM_MAPPING_MAX 256
#define ACRN_MEM_REGION_ADD 0
#define ACRN_MEM_REGION_DEL 2
struct acrn_vm;
struct acrn_ioreq_client;
/**
* struct vm_memory_region_op - Hypervisor memory operation
* @type: Operation type (ACRN_MEM_REGION_*)
@ -75,9 +80,63 @@ struct vm_memory_mapping {
size_t size;
};
/**
* struct acrn_ioreq_buffer - Data for setting the ioreq buffer of User VM
* @ioreq_buf: The GPA of the IO request shared buffer of a VM
*
* The parameter for the HC_SET_IOREQ_BUFFER hypercall used to set up
* the shared I/O request buffer between Service VM and ACRN hypervisor.
*/
struct acrn_ioreq_buffer {
u64 ioreq_buf;
};
struct acrn_ioreq_range {
struct list_head list;
u32 type;
u64 start;
u64 end;
};
#define ACRN_IOREQ_CLIENT_DESTROYING 0U
typedef int (*ioreq_handler_t)(struct acrn_ioreq_client *client,
struct acrn_io_request *req);
/**
* struct acrn_ioreq_client - Structure of I/O client.
* @name: Client name
* @vm: The VM that the client belongs to
* @list: List node for this acrn_ioreq_client
* @is_default: If this client is the default one
* @flags: Flags (ACRN_IOREQ_CLIENT_*)
* @range_list: I/O ranges
* @range_lock: Lock to protect range_list
* @ioreqs_map: The pending I/O requests bitmap.
* @handler: I/O requests handler of this client
* @thread: The thread which executes the handler
* @wq: The wait queue for the handler thread parking
* @priv: Data for the thread
*/
struct acrn_ioreq_client {
char name[ACRN_NAME_LEN];
struct acrn_vm *vm;
struct list_head list;
bool is_default;
unsigned long flags;
struct list_head range_list;
rwlock_t range_lock;
DECLARE_BITMAP(ioreqs_map, ACRN_IO_REQUEST_MAX);
ioreq_handler_t handler;
struct task_struct *thread;
wait_queue_head_t wq;
void *priv;
};
#define ACRN_INVALID_VMID (0xffffU)
#define ACRN_VM_FLAG_DESTROYED 0U
#define ACRN_VM_FLAG_CLEARING_IOREQ 1U
extern struct list_head acrn_vm_list;
extern rwlock_t acrn_vm_list_lock;
/**
* struct acrn_vm - Properties of ACRN User VM.
* @list: Entry within global list of all VMs.
@ -90,6 +149,11 @@ struct vm_memory_mapping {
* &acrn_vm.regions_mapping_count.
* @regions_mapping: Memory mappings of this VM.
* @regions_mapping_count: Number of memory mapping of this VM.
* @ioreq_clients_lock: Lock to protect ioreq_clients and default_client
* @ioreq_clients: The I/O request clients list of this VM
* @default_client: The default I/O request client
* @ioreq_buf: I/O request shared buffer
* @ioreq_page: The page of the I/O request shared buffer
*/
struct acrn_vm {
struct list_head list;
@ -99,6 +163,11 @@ struct acrn_vm {
struct mutex regions_mapping_lock;
struct vm_memory_mapping regions_mapping[ACRN_MEM_MAPPING_MAX];
int regions_mapping_count;
spinlock_t ioreq_clients_lock;
struct list_head ioreq_clients;
struct acrn_ioreq_client *default_client;
struct acrn_io_request_buffer *ioreq_buf;
struct page *ioreq_page;
};
struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
@ -112,4 +181,17 @@ int acrn_vm_memseg_unmap(struct acrn_vm *vm, struct acrn_vm_memmap *memmap);
int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap);
void acrn_vm_all_ram_unmap(struct acrn_vm *vm);
int acrn_ioreq_init(struct acrn_vm *vm, u64 buf_vma);
void acrn_ioreq_deinit(struct acrn_vm *vm);
int acrn_ioreq_intr_setup(void);
void acrn_ioreq_intr_remove(void);
void acrn_ioreq_request_clear(struct acrn_vm *vm);
int acrn_ioreq_client_wait(struct acrn_ioreq_client *client);
int acrn_ioreq_request_default_complete(struct acrn_vm *vm, u16 vcpu);
struct acrn_ioreq_client *acrn_ioreq_client_create(struct acrn_vm *vm,
ioreq_handler_t handler,
void *data, bool is_default,
const char *name);
void acrn_ioreq_client_destroy(struct acrn_ioreq_client *client);
#endif /* __ACRN_HSM_DRV_H */

43
drivers/virt/acrn/hsm.c
View File

@ -48,6 +48,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
struct acrn_vm *vm = filp->private_data;
struct acrn_vm_creation *vm_param;
struct acrn_vcpu_regs *cpu_regs;
struct acrn_ioreq_notify notify;
struct acrn_vm_memmap memmap;
int i, ret = 0;
@ -147,6 +148,35 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
ret = acrn_vm_memseg_unmap(vm, &memmap);
break;
case ACRN_IOCTL_CREATE_IOREQ_CLIENT:
if (vm->default_client)
return -EEXIST;
if (!acrn_ioreq_client_create(vm, NULL, NULL, true, "acrndm"))
ret = -EINVAL;
break;
case ACRN_IOCTL_DESTROY_IOREQ_CLIENT:
if (vm->default_client)
acrn_ioreq_client_destroy(vm->default_client);
break;
case ACRN_IOCTL_ATTACH_IOREQ_CLIENT:
if (vm->default_client)
ret = acrn_ioreq_client_wait(vm->default_client);
else
ret = -ENODEV;
break;
case ACRN_IOCTL_NOTIFY_REQUEST_FINISH:
if (copy_from_user(&notify, (void __user *)ioctl_param,
sizeof(struct acrn_ioreq_notify)))
return -EFAULT;
if (notify.reserved != 0)
return -EINVAL;
ret = acrn_ioreq_request_default_complete(vm, notify.vcpu);
break;
case ACRN_IOCTL_CLEAR_VM_IOREQ:
acrn_ioreq_request_clear(vm);
break;
default:
dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
ret = -ENOTTY;
@ -188,14 +218,23 @@ static int __init hsm_init(void)
return -EPERM;
ret = misc_register(&acrn_dev);
if (ret)
if (ret) {
pr_err("Create misc dev failed!\n");
return ret;
}
return ret;
ret = acrn_ioreq_intr_setup();
if (ret) {
pr_err("Setup I/O request handler failed!\n");
misc_deregister(&acrn_dev);
return ret;
}
return 0;
}
static void __exit hsm_exit(void)
{
acrn_ioreq_intr_remove();
misc_deregister(&acrn_dev);
}
module_init(hsm_init);

28
drivers/virt/acrn/hypercall.h
View File

@ -21,6 +21,10 @@
#define HC_RESET_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x05)
#define HC_SET_VCPU_REGS _HC_ID(HC_ID, HC_ID_VM_BASE + 0x06)
#define HC_ID_IOREQ_BASE 0x30UL
#define HC_SET_IOREQ_BUFFER _HC_ID(HC_ID, HC_ID_IOREQ_BASE + 0x00)
#define HC_NOTIFY_REQUEST_FINISH _HC_ID(HC_ID, HC_ID_IOREQ_BASE + 0x01)
#define HC_ID_MEM_BASE 0x40UL
#define HC_VM_SET_MEMORY_REGIONS _HC_ID(HC_ID, HC_ID_MEM_BASE + 0x02)
@ -91,6 +95,30 @@ static inline long hcall_set_vcpu_regs(u64 vmid, u64 regs_state)
return acrn_hypercall2(HC_SET_VCPU_REGS, vmid, regs_state);
}
/**
* hcall_set_ioreq_buffer() - Set up the shared buffer for I/O Requests.
* @vmid: User VM ID
* @buffer: Service VM GPA of the shared buffer
*
* Return: 0 on success, <0 on failure
*/
static inline long hcall_set_ioreq_buffer(u64 vmid, u64 buffer)
{
return acrn_hypercall2(HC_SET_IOREQ_BUFFER, vmid, buffer);
}
/**
* hcall_notify_req_finish() - Notify ACRN Hypervisor of I/O request completion.
* @vmid: User VM ID
* @vcpu: The vCPU which initiated the I/O request
*
* Return: 0 on success, <0 on failure
*/
static inline long hcall_notify_req_finish(u64 vmid, u64 vcpu)
{
return acrn_hypercall2(HC_NOTIFY_REQUEST_FINISH, vmid, vcpu);
}
/**
* hcall_set_memory_regions() - Inform the hypervisor to set up EPT mappings
* @regions_pa: Service VM GPA of &struct vm_memory_region_batch

521
drivers/virt/acrn/ioreq.c Normal file
View File

@ -0,0 +1,521 @@
// SPDX-License-Identifier: GPL-2.0
/*
* ACRN_HSM: Handle I/O requests
*
* Copyright (C) 2020 Intel Corporation. All rights reserved.
*
* Authors:
* Jason Chen CJ <jason.cj.chen@intel.com>
* Fengwei Yin <fengwei.yin@intel.com>
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kthread.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/acrn.h>
#include "acrn_drv.h"
static void ioreq_pause(void);
static void ioreq_resume(void);
static void ioreq_dispatcher(struct work_struct *work);
static struct workqueue_struct *ioreq_wq;
static DECLARE_WORK(ioreq_work, ioreq_dispatcher);
static inline bool has_pending_request(struct acrn_ioreq_client *client)
{
return !bitmap_empty(client->ioreqs_map, ACRN_IO_REQUEST_MAX);
}
static inline bool is_destroying(struct acrn_ioreq_client *client)
{
return test_bit(ACRN_IOREQ_CLIENT_DESTROYING, &client->flags);
}
static int ioreq_complete_request(struct acrn_vm *vm, u16 vcpu,
struct acrn_io_request *acrn_req)
{
bool polling_mode;
int ret = 0;
polling_mode = acrn_req->completion_polling;
/* Add barrier() to make sure the writes are done before completion */
smp_store_release(&acrn_req->processed, ACRN_IOREQ_STATE_COMPLETE);
/*
* To fulfill the requirement of real-time in several industry
* scenarios, like automotive, ACRN can run under the partition mode,
* in which User VMs and Service VM are bound to dedicated CPU cores.
* Polling mode of handling the I/O request is introduced to achieve a
* faster I/O request handling. In polling mode, the hypervisor polls
* I/O request's completion. Once an I/O request is marked as
* ACRN_IOREQ_STATE_COMPLETE, hypervisor resumes from the polling point
* to continue the I/O request flow. Thus, the completion notification
* from HSM of I/O request is not needed. Please note,
* completion_polling needs to be read before the I/O request being
* marked as ACRN_IOREQ_STATE_COMPLETE to avoid racing with the
* hypervisor.
*/
if (!polling_mode) {
ret = hcall_notify_req_finish(vm->vmid, vcpu);
if (ret < 0)
dev_err(acrn_dev.this_device,
"Notify I/O request finished failed!\n");
}
return ret;
}
static int acrn_ioreq_complete_request(struct acrn_ioreq_client *client,
u16 vcpu,
struct acrn_io_request *acrn_req)
{
int ret;
if (vcpu >= client->vm->vcpu_num)
return -EINVAL;
clear_bit(vcpu, client->ioreqs_map);
if (!acrn_req) {
acrn_req = (struct acrn_io_request *)client->vm->ioreq_buf;
acrn_req += vcpu;
}
ret = ioreq_complete_request(client->vm, vcpu, acrn_req);
return ret;
}
int acrn_ioreq_request_default_complete(struct acrn_vm *vm, u16 vcpu)
{
int ret = 0;
spin_lock_bh(&vm->ioreq_clients_lock);
if (vm->default_client)
ret = acrn_ioreq_complete_request(vm->default_client,
vcpu, NULL);
spin_unlock_bh(&vm->ioreq_clients_lock);
return ret;
}
/*
* ioreq_task() is the execution entity of handler thread of an I/O client.
* The handler callback of the I/O client is called within the handler thread.
*/
static int ioreq_task(void *data)
{
struct acrn_ioreq_client *client = data;
struct acrn_io_request *req;
unsigned long *ioreqs_map;
int vcpu, ret;
/*
* Lockless access to ioreqs_map is safe, because
* 1) set_bit() and clear_bit() are atomic operations.
* 2) I/O requests arrives serialized. The access flow of ioreqs_map is:
* set_bit() - in ioreq_work handler
* Handler callback handles corresponding I/O request
* clear_bit() - in handler thread (include ACRN userspace)
* Mark corresponding I/O request completed
* Loop again if a new I/O request occurs
*/
ioreqs_map = client->ioreqs_map;
while (!kthread_should_stop()) {
acrn_ioreq_client_wait(client);
while (has_pending_request(client)) {
vcpu = find_first_bit(ioreqs_map, client->vm->vcpu_num);
req = client->vm->ioreq_buf->req_slot + vcpu;
ret = client->handler(client, req);
if (ret < 0) {
dev_err(acrn_dev.this_device,
"IO handle failure: %d\n", ret);
break;
}
acrn_ioreq_complete_request(client, vcpu, req);
}
}
return 0;
}
/*
* For the non-default I/O clients, give them chance to complete the current
* I/O requests if there are any. For the default I/O client, it is safe to
* clear all pending I/O requests because the clearing request is from ACRN
* userspace.
*/
void acrn_ioreq_request_clear(struct acrn_vm *vm)
{
struct acrn_ioreq_client *client;
bool has_pending = false;
unsigned long vcpu;
int retry = 10;
/*
* IO requests of this VM will be completed directly in
* acrn_ioreq_dispatch if ACRN_VM_FLAG_CLEARING_IOREQ flag is set.
*/
set_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags);
/*
* acrn_ioreq_request_clear is only called in VM reset case. Simply
* wait 100ms in total for the IO requests' completion.
*/
do {
spin_lock_bh(&vm->ioreq_clients_lock);
list_for_each_entry(client, &vm->ioreq_clients, list) {
has_pending = has_pending_request(client);
if (has_pending)
break;
}
spin_unlock_bh(&vm->ioreq_clients_lock);
if (has_pending)
schedule_timeout_interruptible(HZ / 100);
} while (has_pending && --retry > 0);
if (retry == 0)
dev_warn(acrn_dev.this_device,
"%s cannot flush pending request!\n", client->name);
/* Clear all ioreqs belonging to the default client */
spin_lock_bh(&vm->ioreq_clients_lock);
client = vm->default_client;
if (client) {
vcpu = find_next_bit(client->ioreqs_map,
ACRN_IO_REQUEST_MAX, 0);
while (vcpu < ACRN_IO_REQUEST_MAX) {
acrn_ioreq_complete_request(client, vcpu, NULL);
vcpu = find_next_bit(client->ioreqs_map,
ACRN_IO_REQUEST_MAX, vcpu + 1);
}
}
spin_unlock_bh(&vm->ioreq_clients_lock);
/* Clear ACRN_VM_FLAG_CLEARING_IOREQ flag after the clearing */
clear_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags);
}
int acrn_ioreq_client_wait(struct acrn_ioreq_client *client)
{
if (client->is_default) {
/*
* In the default client, a user space thread waits on the
* waitqueue. The is_destroying() check is used to notify user
* space the client is going to be destroyed.
*/
wait_event_interruptible(client->wq,
has_pending_request(client) ||
is_destroying(client));
if (is_destroying(client))
return -ENODEV;
} else {
wait_event_interruptible(client->wq,
has_pending_request(client) ||
kthread_should_stop());
}
return 0;
}
static bool in_range(struct acrn_ioreq_range *range,
struct acrn_io_request *req)
{
bool ret = false;
if (range->type == req->type) {
switch (req->type) {
case ACRN_IOREQ_TYPE_MMIO:
if (req->reqs.mmio_request.address >= range->start &&
(req->reqs.mmio_request.address +
req->reqs.mmio_request.size - 1) <= range->end)
ret = true;
break;
case ACRN_IOREQ_TYPE_PORTIO:
if (req->reqs.pio_request.address >= range->start &&
(req->reqs.pio_request.address +
req->reqs.pio_request.size - 1) <= range->end)
ret = true;
break;
default:
break;
}
}
return ret;
}
static struct acrn_ioreq_client *find_ioreq_client(struct acrn_vm *vm,
struct acrn_io_request *req)
{
struct acrn_ioreq_client *client, *found = NULL;
struct acrn_ioreq_range *range;
lockdep_assert_held(&vm->ioreq_clients_lock);
list_for_each_entry(client, &vm->ioreq_clients, list) {
read_lock_bh(&client->range_lock);
list_for_each_entry(range, &client->range_list, list) {
if (in_range(range, req)) {
found = client;
break;
}
}
read_unlock_bh(&client->range_lock);
if (found)
break;
}
return found ? found : vm->default_client;
}
/**
* acrn_ioreq_client_create() - Create an ioreq client
* @vm: The VM that this client belongs to
* @handler: The ioreq_handler of ioreq client acrn_hsm will create a kernel
* thread and call the handler to handle I/O requests.
* @priv: Private data for the handler
* @is_default: If it is the default client
* @name: The name of ioreq client
*
* Return: acrn_ioreq_client pointer on success, NULL on error
*/
struct acrn_ioreq_client *acrn_ioreq_client_create(struct acrn_vm *vm,
ioreq_handler_t handler,
void *priv, bool is_default,
const char *name)
{
struct acrn_ioreq_client *client;
if (!handler && !is_default) {
dev_dbg(acrn_dev.this_device,
"Cannot create non-default client w/o handler!\n");
return NULL;
}
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client)
return NULL;
client->handler = handler;
client->vm = vm;
client->priv = priv;
client->is_default = is_default;
if (name)
strncpy(client->name, name, sizeof(client->name) - 1);
rwlock_init(&client->range_lock);
INIT_LIST_HEAD(&client->range_list);
init_waitqueue_head(&client->wq);
if (client->handler) {
client->thread = kthread_run(ioreq_task, client, "VM%u-%s",
client->vm->vmid, client->name);
if (IS_ERR(client->thread)) {
kfree(client);
return NULL;
}
}
spin_lock_bh(&vm->ioreq_clients_lock);
if (is_default)
vm->default_client = client;
else
list_add(&client->list, &vm->ioreq_clients);
spin_unlock_bh(&vm->ioreq_clients_lock);
dev_dbg(acrn_dev.this_device, "Created ioreq client %s.\n", name);
return client;
}
/**
* acrn_ioreq_client_destroy() - Destroy an ioreq client
* @client: The ioreq client
*/
void acrn_ioreq_client_destroy(struct acrn_ioreq_client *client)
{
struct acrn_ioreq_range *range, *next;
struct acrn_vm *vm = client->vm;
dev_dbg(acrn_dev.this_device,
"Destroy ioreq client %s.\n", client->name);
ioreq_pause();
set_bit(ACRN_IOREQ_CLIENT_DESTROYING, &client->flags);
if (client->is_default)
wake_up_interruptible(&client->wq);
else
kthread_stop(client->thread);
spin_lock_bh(&vm->ioreq_clients_lock);
if (client->is_default)
vm->default_client = NULL;
else
list_del(&client->list);
spin_unlock_bh(&vm->ioreq_clients_lock);
write_lock_bh(&client->range_lock);
list_for_each_entry_safe(range, next, &client->range_list, list) {
list_del(&range->list);
kfree(range);
}
write_unlock_bh(&client->range_lock);
kfree(client);
ioreq_resume();
}
static int acrn_ioreq_dispatch(struct acrn_vm *vm)
{
struct acrn_ioreq_client *client;
struct acrn_io_request *req;
int i;
for (i = 0; i < vm->vcpu_num; i++) {
req = vm->ioreq_buf->req_slot + i;
/* barrier the read of processed of acrn_io_request */
if (smp_load_acquire(&req->processed) ==
ACRN_IOREQ_STATE_PENDING) {
/* Complete the IO request directly in clearing stage */
if (test_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags)) {
ioreq_complete_request(vm, i, req);
continue;
}
spin_lock_bh(&vm->ioreq_clients_lock);
client = find_ioreq_client(vm, req);
if (!client) {
dev_err(acrn_dev.this_device,
"Failed to find ioreq client!\n");
spin_unlock_bh(&vm->ioreq_clients_lock);
return -EINVAL;
}
if (!client->is_default)
req->kernel_handled = 1;
else
req->kernel_handled = 0;
/*
* Add barrier() to make sure the writes are done
* before setting ACRN_IOREQ_STATE_PROCESSING
*/
smp_store_release(&req->processed,
ACRN_IOREQ_STATE_PROCESSING);
set_bit(i, client->ioreqs_map);
wake_up_interruptible(&client->wq);
spin_unlock_bh(&vm->ioreq_clients_lock);
}
}
return 0;
}
static void ioreq_dispatcher(struct work_struct *work)
{
struct acrn_vm *vm;
read_lock(&acrn_vm_list_lock);
list_for_each_entry(vm, &acrn_vm_list, list) {
if (!vm->ioreq_buf)
break;
acrn_ioreq_dispatch(vm);
}
read_unlock(&acrn_vm_list_lock);
}
static void ioreq_intr_handler(void)
{
queue_work(ioreq_wq, &ioreq_work);
}
static void ioreq_pause(void)
{
/* Flush and unarm the handler to ensure no I/O requests pending */
acrn_remove_intr_handler();
drain_workqueue(ioreq_wq);
}
static void ioreq_resume(void)
{
/* Schedule after enabling in case other clients miss interrupt */
acrn_setup_intr_handler(ioreq_intr_handler);
queue_work(ioreq_wq, &ioreq_work);
}
int acrn_ioreq_intr_setup(void)
{
acrn_setup_intr_handler(ioreq_intr_handler);
ioreq_wq = alloc_workqueue("ioreq_wq",
WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
if (!ioreq_wq) {
dev_err(acrn_dev.this_device, "Failed to alloc workqueue!\n");
acrn_remove_intr_handler();
return -ENOMEM;
}
return 0;
}
void acrn_ioreq_intr_remove(void)
{
if (ioreq_wq)
destroy_workqueue(ioreq_wq);
acrn_remove_intr_handler();
}
int acrn_ioreq_init(struct acrn_vm *vm, u64 buf_vma)
{
struct acrn_ioreq_buffer *set_buffer;
struct page *page;
int ret;
if (vm->ioreq_buf)
return -EEXIST;
set_buffer = kzalloc(sizeof(*set_buffer), GFP_KERNEL);
if (!set_buffer)
return -ENOMEM;
ret = pin_user_pages_fast(buf_vma, 1,
FOLL_WRITE | FOLL_LONGTERM, &page);
if (unlikely(ret != 1) || !page) {
dev_err(acrn_dev.this_device, "Failed to pin ioreq page!\n");
ret = -EFAULT;
goto free_buf;
}
vm->ioreq_buf = page_address(page);
vm->ioreq_page = page;
set_buffer->ioreq_buf = page_to_phys(page);
ret = hcall_set_ioreq_buffer(vm->vmid, virt_to_phys(set_buffer));
if (ret < 0) {
dev_err(acrn_dev.this_device, "Failed to init ioreq buffer!\n");
unpin_user_page(page);
vm->ioreq_buf = NULL;
goto free_buf;
}
dev_dbg(acrn_dev.this_device,
"Init ioreq buffer %pK!\n", vm->ioreq_buf);
ret = 0;
free_buf:
kfree(set_buffer);
return ret;
}
void acrn_ioreq_deinit(struct acrn_vm *vm)
{
struct acrn_ioreq_client *client, *next;
dev_dbg(acrn_dev.this_device,
"Deinit ioreq buffer %pK!\n", vm->ioreq_buf);
/* Destroy all clients belonging to this VM */
list_for_each_entry_safe(client, next, &vm->ioreq_clients, list)
acrn_ioreq_client_destroy(client);
if (vm->default_client)
acrn_ioreq_client_destroy(vm->default_client);
if (vm->ioreq_buf && vm->ioreq_page) {
unpin_user_page(vm->ioreq_page);
vm->ioreq_buf = NULL;
}
}

27
drivers/virt/acrn/vm.c
View File

@ -15,9 +15,12 @@
#include "acrn_drv.h"
/* List of VMs */
static LIST_HEAD(acrn_vm_list);
/* To protect acrn_vm_list */
static DEFINE_MUTEX(acrn_vm_list_lock);
LIST_HEAD(acrn_vm_list);
/*
* acrn_vm_list is read in a worker thread which dispatch I/O requests and
* is wrote in VM creation ioctl. Use the rwlock mechanism to protect it.
*/
DEFINE_RWLOCK(acrn_vm_list_lock);
struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
struct acrn_vm_creation *vm_param)
@ -32,12 +35,20 @@ struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
}
mutex_init(&vm->regions_mapping_lock);
INIT_LIST_HEAD(&vm->ioreq_clients);
spin_lock_init(&vm->ioreq_clients_lock);
vm->vmid = vm_param->vmid;
vm->vcpu_num = vm_param->vcpu_num;
mutex_lock(&acrn_vm_list_lock);
if (acrn_ioreq_init(vm, vm_param->ioreq_buf) < 0) {
hcall_destroy_vm(vm_param->vmid);
vm->vmid = ACRN_INVALID_VMID;
return NULL;
}
write_lock_bh(&acrn_vm_list_lock);
list_add(&vm->list, &acrn_vm_list);
mutex_unlock(&acrn_vm_list_lock);
write_unlock_bh(&acrn_vm_list_lock);
dev_dbg(acrn_dev.this_device, "VM %u created.\n", vm->vmid);
return vm;
@ -52,9 +63,11 @@ int acrn_vm_destroy(struct acrn_vm *vm)
return 0;
/* Remove from global VM list */
mutex_lock(&acrn_vm_list_lock);
write_lock_bh(&acrn_vm_list_lock);
list_del_init(&vm->list);
mutex_unlock(&acrn_vm_list_lock);
write_unlock_bh(&acrn_vm_list_lock);
acrn_ioreq_deinit(vm);
ret = hcall_destroy_vm(vm->vmid);
if (ret < 0) {

150
include/uapi/linux/acrn.h
View File

@ -14,6 +14,145 @@
#include <linux/types.h>
#include <linux/uuid.h>
#define ACRN_IO_REQUEST_MAX 16
#define ACRN_IOREQ_STATE_PENDING 0
#define ACRN_IOREQ_STATE_COMPLETE 1
#define ACRN_IOREQ_STATE_PROCESSING 2
#define ACRN_IOREQ_STATE_FREE 3
#define ACRN_IOREQ_TYPE_PORTIO 0
#define ACRN_IOREQ_TYPE_MMIO 1
#define ACRN_IOREQ_DIR_READ 0
#define ACRN_IOREQ_DIR_WRITE 1
/**
* struct acrn_mmio_request - Info of a MMIO I/O request
* @direction: Access direction of this request (ACRN_IOREQ_DIR_*)
* @reserved: Reserved for alignment and should be 0
* @address: Access address of this MMIO I/O request
* @size: Access size of this MMIO I/O request
* @value: Read/write value of this MMIO I/O request
*/
struct acrn_mmio_request {
__u32 direction;
__u32 reserved;
__u64 address;
__u64 size;
__u64 value;
};
/**
* struct acrn_pio_request - Info of a PIO I/O request
* @direction: Access direction of this request (ACRN_IOREQ_DIR_*)
* @reserved: Reserved for alignment and should be 0
* @address: Access address of this PIO I/O request
* @size: Access size of this PIO I/O request
* @value: Read/write value of this PIO I/O request
*/
struct acrn_pio_request {
__u32 direction;
__u32 reserved;
__u64 address;
__u64 size;
__u32 value;
};
/**
* struct acrn_io_request - 256-byte ACRN I/O request
* @type: Type of this request (ACRN_IOREQ_TYPE_*).
* @completion_polling: Polling flag. Hypervisor will poll completion of the
* I/O request if this flag set.
* @reserved0: Reserved fields.
* @reqs: Union of different types of request. Byte offset: 64.
* @reqs.pio_request: PIO request data of the I/O request.
* @reqs.mmio_request: MMIO request data of the I/O request.
* @reqs.data: Raw data of the I/O request.
* @reserved1: Reserved fields.
* @kernel_handled: Flag indicates this request need be handled in kernel.
* @processed: The status of this request (ACRN_IOREQ_STATE_*).
*
* The state transitions of ACRN I/O request:
*
* FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...
*
* 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.
*
* On basis of the states illustrated above, a typical lifecycle of ACRN IO
* request would look like:
*
* Flow (assume the initial state is FREE)
* |
* | Service VM vCPU 0 Service VM vCPU x User vCPU y
* |
* | hypervisor:
* | fills in type, addr, etc.
* | pauses the User VM vCPU y
* | sets the state to PENDING (a)
* | fires an upcall to Service VM
* |
* | HSM:
* | scans for PENDING requests
* | sets the states to PROCESSING (b)
* | assigns the requests to clients (c)
* V
* | client:
* | scans for the assigned requests
* | handles the requests (d)
* | HSM:
* | sets states to COMPLETE
* | notifies the hypervisor
* |
* | hypervisor:
* | resumes User VM vCPU y (e)
* |
* | hypervisor:
* | post handling (f)
* V sets states to FREE
*
* Note that the procedures (a) to (f) in the illustration above require to be
* strictly processed in the order. One vCPU cannot trigger another request of
* I/O emulation before completing the previous one.
*
* Atomic and barriers are required when HSM and hypervisor accessing the state
* of &struct acrn_io_request.
*
*/
struct acrn_io_request {
__u32 type;
__u32 completion_polling;
__u32 reserved0[14];
union {
struct acrn_pio_request pio_request;
struct acrn_mmio_request mmio_request;
__u64 data[8];
} reqs;
__u32 reserved1;
__u32 kernel_handled;
__u32 processed;
} __attribute__((aligned(256)));
struct acrn_io_request_buffer {
union {
struct acrn_io_request req_slot[ACRN_IO_REQUEST_MAX];
__u8 reserved[4096];
};
};
/**
* struct acrn_ioreq_notify - The structure of ioreq completion notification
* @vmid: User VM ID
* @reserved: Reserved and should be 0
* @vcpu: vCPU ID
*/
struct acrn_ioreq_notify {
__u16 vmid;
__u16 reserved;
__u32 vcpu;
};
/**
* struct acrn_vm_creation - Info to create a User VM
* @vmid: User VM ID returned from the hypervisor
@ -218,6 +357,17 @@ struct acrn_vm_memmap {
#define ACRN_IOCTL_SET_VCPU_REGS \
_IOW(ACRN_IOCTL_TYPE, 0x16, struct acrn_vcpu_regs)
#define ACRN_IOCTL_NOTIFY_REQUEST_FINISH \
_IOW(ACRN_IOCTL_TYPE, 0x31, struct acrn_ioreq_notify)
#define ACRN_IOCTL_CREATE_IOREQ_CLIENT \
_IO(ACRN_IOCTL_TYPE, 0x32)
#define ACRN_IOCTL_ATTACH_IOREQ_CLIENT \
_IO(ACRN_IOCTL_TYPE, 0x33)
#define ACRN_IOCTL_DESTROY_IOREQ_CLIENT \
_IO(ACRN_IOCTL_TYPE, 0x34)
#define ACRN_IOCTL_CLEAR_VM_IOREQ \
_IO(ACRN_IOCTL_TYPE, 0x35)
#define ACRN_IOCTL_SET_MEMSEG \
_IOW(ACRN_IOCTL_TYPE, 0x41, struct acrn_vm_memmap)
#define ACRN_IOCTL_UNSET_MEMSEG \