lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CACLfguV5v8Pm9=+0jkDnZFLp-MiyoYT=cFsA2rqeVgNJ2O7zvQ@mail.gmail.com>
Date: Mon, 7 Apr 2025 11:13:42 +0800
From: Cindy Lu <lulu@...hat.com>
To: Stefano Garzarella <sgarzare@...hat.com>
Cc: jasowang@...hat.com, mst@...hat.com, michael.christie@...cle.com, 
	linux-kernel@...r.kernel.org, virtualization@...ts.linux-foundation.org, 
	netdev@...r.kernel.org
Subject: Re: [PATCH v8 4/8] vhost: Introduce vhost_worker_ops in vhost_worker

On Tue, Apr 1, 2025 at 9:48 PM Stefano Garzarella <sgarzare@...hat.com> wrote:
>
> On Fri, Mar 28, 2025 at 06:02:48PM +0800, Cindy Lu wrote:
> >Abstract vhost worker operations (create/stop/wakeup) into an ops
> >structure to prepare for kthread mode support.
> >
> >Signed-off-by: Cindy Lu <lulu@...hat.com>
> >---
> > drivers/vhost/vhost.c | 63 ++++++++++++++++++++++++++++++-------------
> > drivers/vhost/vhost.h | 11 ++++++++
> > 2 files changed, 56 insertions(+), 18 deletions(-)
> >
> >diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> >index 20571bd6f7bd..c162ad772f8f 100644
> >--- a/drivers/vhost/vhost.c
> >+++ b/drivers/vhost/vhost.c
> >@@ -243,7 +243,7 @@ static void vhost_worker_queue(struct vhost_worker *worker,
> >                * test_and_set_bit() implies a memory barrier.
> >                */
> >               llist_add(&work->node, &worker->work_list);
> >-              vhost_task_wake(worker->vtsk);
> >+              worker->ops->wakeup(worker);
> >       }
> > }
> >
> >@@ -706,7 +706,7 @@ static void vhost_worker_destroy(struct vhost_dev *dev,
> >
> >       WARN_ON(!llist_empty(&worker->work_list));
> >       xa_erase(&dev->worker_xa, worker->id);
> >-      vhost_task_stop(worker->vtsk);
> >+      worker->ops->stop(worker);
> >       kfree(worker);
> > }
> >
> >@@ -729,42 +729,69 @@ static void vhost_workers_free(struct vhost_dev *dev)
> >       xa_destroy(&dev->worker_xa);
> > }
> >
> >+static void vhost_task_wakeup(struct vhost_worker *worker)
> >+{
> >+      return vhost_task_wake(worker->vtsk);
> >+}
> >+
> >+static void vhost_task_do_stop(struct vhost_worker *worker)
> >+{
> >+      return vhost_task_stop(worker->vtsk);
> >+}
> >+
> >+static int vhost_task_worker_create(struct vhost_worker *worker,
> >+                                  struct vhost_dev *dev, const char *name)
> >+{
> >+      struct vhost_task *vtsk;
> >+      u32 id;
> >+      int ret;
> >+
> >+      vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed,
> >+                               worker, name);
> >+      if (IS_ERR(vtsk))
> >+              return PTR_ERR(vtsk);
> >+
> >+      worker->vtsk = vtsk;
> >+      vhost_task_start(vtsk);
> >+      ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL);
> >+      if (ret < 0) {
> >+              vhost_task_do_stop(worker);
> >+              return ret;
> >+      }
>
> In the final code, xa_alloc() is duplicated among the functions that
> create ktrhead or task, might it make sense to leave it out and do it in
> vhost_worker_create() ?
>
> Thanks,
> Stefano
>
Thanks a lot Stefano. I previously tried moving xa_alloc() out, but
that made the code strange.
I think keeping xa_alloc() in the create_ops function completes the
job in  a single function, and maybe it could be used in some other
functions in the future
thanks
cindy

> >+      worker->id = id;
> >+      return 0;
> >+}
> >+
> >+static const struct vhost_worker_ops vhost_task_ops = {
> >+      .create = vhost_task_worker_create,
> >+      .stop = vhost_task_do_stop,
> >+      .wakeup = vhost_task_wakeup,
> >+};
> >+
> > 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;
> >+      const struct vhost_worker_ops *ops = &vhost_task_ops;
> >
> >       worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT);
> >       if (!worker)
> >               return NULL;
> >
> >       worker->dev = dev;
> >+      worker->ops = ops;
> >       snprintf(name, sizeof(name), "vhost-%d", current->pid);
> >
> >-      vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed,
> >-                               worker, name);
> >-      if (IS_ERR(vtsk))
> >-              goto free_worker;
> >-
> >       mutex_init(&worker->mutex);
> >       init_llist_head(&worker->work_list);
> >       worker->kcov_handle = kcov_common_handle();
> >-      worker->vtsk = vtsk;
> >-
> >-      vhost_task_start(vtsk);
> >-
> >-      ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL);
> >+      ret = ops->create(worker, dev, name);
> >       if (ret < 0)
> >-              goto stop_worker;
> >-      worker->id = id;
> >+              goto free_worker;
> >
> >       return worker;
> >
> >-stop_worker:
> >-      vhost_task_stop(vtsk);
> > free_worker:
> >       kfree(worker);
> >       return NULL;
> >diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> >index 19bb94922a0e..98895e299efa 100644
> >--- a/drivers/vhost/vhost.h
> >+++ b/drivers/vhost/vhost.h
> >@@ -26,6 +26,16 @@ struct vhost_work {
> >       unsigned long           flags;
> > };
> >
> >+struct vhost_worker;
> >+struct vhost_dev;
> >+
> >+struct vhost_worker_ops {
> >+      int (*create)(struct vhost_worker *worker, struct vhost_dev *dev,
> >+                    const char *name);
> >+      void (*stop)(struct vhost_worker *worker);
> >+      void (*wakeup)(struct vhost_worker *worker);
> >+};
> >+
> > struct vhost_worker {
> >       struct vhost_task       *vtsk;
> >       struct vhost_dev        *dev;
> >@@ -36,6 +46,7 @@ struct vhost_worker {
> >       u32                     id;
> >       int                     attachment_cnt;
> >       bool                    killed;
> >+      const struct vhost_worker_ops *ops;
> > };
> >
> > /* Poll a file (eventfd or socket) */
> >--
> >2.45.0
> >
>


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ