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vhost: replace single worker pointer with xarray

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The next patch allows userspace to create multiple workers per device,
so this patch replaces the vhost_worker pointer with an xarray so we
can store mupltiple workers and look them up.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20230626232307.97930-15-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Mike Christie 2023-06-26 18:23:04 -05:00 committed by Michael S. Tsirkin
parent cef25866f4
commit 1cdaafa1b8
2 changed files with 50 additions and 17 deletions
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64
drivers/vhost/vhost.c
View File

@ -280,7 +280,11 @@ EXPORT_SYMBOL_GPL(vhost_vq_flush);
void vhost_dev_flush(struct vhost_dev *dev)
{
vhost_worker_flush(dev->worker);
struct vhost_worker *worker;
unsigned long i;
xa_for_each(&dev->worker_xa, i, worker)
vhost_worker_flush(worker);
}
EXPORT_SYMBOL_GPL(vhost_dev_flush);
@ -482,7 +486,6 @@ void vhost_dev_init(struct vhost_dev *dev,
dev->umem = NULL;
dev->iotlb = NULL;
dev->mm = NULL;
dev->worker = NULL;
dev->iov_limit = iov_limit;
dev->weight = weight;
dev->byte_weight = byte_weight;
@ -492,7 +495,7 @@ void vhost_dev_init(struct vhost_dev *dev,
INIT_LIST_HEAD(&dev->read_list);
INIT_LIST_HEAD(&dev->pending_list);
spin_lock_init(&dev->iotlb_lock);
xa_init_flags(&dev->worker_xa, XA_FLAGS_ALLOC);
for (i = 0; i < dev->nvqs; ++i) {
vq = dev->vqs[i];
@ -554,15 +557,35 @@ static void vhost_detach_mm(struct vhost_dev *dev)
dev->mm = NULL;
}
static void vhost_worker_free(struct vhost_dev *dev)
static void vhost_worker_destroy(struct vhost_dev *dev,
struct vhost_worker *worker)
{
if (!dev->worker)
if (!worker)
return;
WARN_ON(!llist_empty(&dev->worker->work_list));
vhost_task_stop(dev->worker->vtsk);
kfree(dev->worker);
dev->worker = NULL;
WARN_ON(!llist_empty(&worker->work_list));
xa_erase(&dev->worker_xa, worker->id);
vhost_task_stop(worker->vtsk);
kfree(worker);
}
static void vhost_workers_free(struct vhost_dev *dev)
{
struct vhost_worker *worker;
unsigned long i;
if (!dev->use_worker)
return;
for (i = 0; i < dev->nvqs; i++)
dev->vqs[i]->worker = NULL;
/*
* Free the default worker we created and cleanup workers userspace
* created but couldn't clean up (it forgot or crashed).
*/
xa_for_each(&dev->worker_xa, i, worker)
vhost_worker_destroy(dev, worker);
xa_destroy(&dev->worker_xa);
}
static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev)
@ -570,6 +593,8 @@ static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev)
struct vhost_worker *worker;
struct vhost_task *vtsk;
char name[TASK_COMM_LEN];
int ret;
u32 id;
worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT);
if (!worker)
@ -584,16 +609,18 @@ static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev)
init_llist_head(&worker->work_list);
worker->kcov_handle = kcov_common_handle();
worker->vtsk = vtsk;
/*
* vsock can already try to queue so make sure llist and vtsk are both
* set before vhost_work_queue sees dev->worker is set.
*/
smp_wmb();
dev->worker = worker;
vhost_task_start(vtsk);
ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL);
if (ret < 0)
goto stop_worker;
worker->id = id;
return worker;
stop_worker:
vhost_task_stop(vtsk);
free_worker:
kfree(worker);
return NULL;
@ -650,6 +677,11 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
err = -ENOMEM;
goto err_worker;
}
/*
* vsock can already try to queue so make sure the worker
* is setup before vhost_vq_work_queue sees vq->worker is set.
*/
smp_wmb();
for (i = 0; i < dev->nvqs; i++)
dev->vqs[i]->worker = worker;
@ -751,7 +783,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
dev->iotlb = NULL;
vhost_clear_msg(dev);
wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM);
vhost_worker_free(dev);
vhost_workers_free(dev);
vhost_detach_mm(dev);
}
EXPORT_SYMBOL_GPL(vhost_dev_cleanup);

3
drivers/vhost/vhost.h
View File

@ -30,6 +30,7 @@ struct vhost_worker {
struct vhost_task *vtsk;
struct llist_head work_list;
u64 kcov_handle;
u32 id;
};
/* Poll a file (eventfd or socket) */
@ -159,7 +160,6 @@ struct vhost_dev {
struct vhost_virtqueue **vqs;
int nvqs;
struct eventfd_ctx *log_ctx;
struct vhost_worker *worker;
struct vhost_iotlb *umem;
struct vhost_iotlb *iotlb;
spinlock_t iotlb_lock;
@ -169,6 +169,7 @@ struct vhost_dev {
int iov_limit;
int weight;
int byte_weight;
struct xarray worker_xa;
bool use_worker;
int (*msg_handler)(struct vhost_dev *dev, u32 asid,
struct vhost_iotlb_msg *msg);