search for: get_task_mm

...* unbounded/indefinite amount of time. > >I wonder if everything would be simplified if we just allow the parent >to advertise whether or not it requires the address space. > >Then when vhost-vDPA probes the device it can simply advertise >use_work as true so vhost core can use get_task_mm() in this case? IIUC set user_worker to true, it also creates the kthread in the vhost core (but we can add another variable to avoid this). My biggest concern is the comment in include/linux/sched/mm.h. get_task_mm() uses mmget(), but in the documentation they advise against pinning the address...

...; >> >I wonder if everything would be simplified if we just allow the parent >> >to advertise whether or not it requires the address space. >> > >> >Then when vhost-vDPA probes the device it can simply advertise >> >use_work as true so vhost core can use get_task_mm() in this case? >> >> IIUC set user_worker to true, it also creates the kthread in the vhost >> core (but we can add another variable to avoid this). >> >> My biggest concern is the comment in include/linux/sched/mm.h. >> get_task_mm() uses mmget(), but in the do...

lguest needs to hold a reference to its task in case it exits while another Guest is sending it I/O. Otherwise we can oops in access_process_vm->get_task_mm->task_lock(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- drivers/lguest/lguest_user.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) =================================================================== --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lgu...

...ddress space for an > * unbounded/indefinite amount of time. I wonder if everything would be simplified if we just allow the parent to advertise whether or not it requires the address space. Then when vhost-vDPA probes the device it can simply advertise use_work as true so vhost core can use get_task_mm() in this case? Thanks > > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > > Notes: > v3: > - called mmget_not_zero() before kthread_use_mm() [Jason] > As the documentation of mmget() in include/linux/sched/mm.h says: > >...

On Mon, Aug 22, 2016 at 08:16:17AM -0600, Jonathan Corbet wrote: > On Mon, 22 Aug 2016 16:57:46 +0300 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > commit commit ea04036032edda6f771c1381d03832d2ed0f6c31 ("CodingStyle: > > add some more error handling guidelines") suggests never naming goto > > labels after the goto location - that is

On Mon, Aug 22, 2016 at 08:16:17AM -0600, Jonathan Corbet wrote: > On Mon, 22 Aug 2016 16:57:46 +0300 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > commit commit ea04036032edda6f771c1381d03832d2ed0f6c31 ("CodingStyle: > > add some more error handling guidelines") suggests never naming goto > > labels after the goto location - that is

...* belows. > */ This comment made it, just at the store side: /* * Serialize the update against mmu_notifier_unregister. A * side note: mmu_notifier_release can't run concurrently with * us because we hold the mm_users pin (either implicitly as * current->mm or explicitly with get_task_mm() or similar). * We can't race against any other mmu notifier method either * thanks to mm_take_all_locks(). * * release semantics on the initialization of the mmu_notifier_mm's * contents are provided for unlocked readers. acquire can only be * used while holding...

...f --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index df9bf1fd1bc0b..3ec5da025bea7 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -171,6 +171,11 @@ nouveau_svmm_bind(struct drm_device *dev, void *data, mm = get_task_mm(current); down_read(&mm->mmap_sem); + if (!cli->svm.svmm) { + up_read(&mm->mmap_sem); + return -EINVAL; + } + for (addr = args->va_start, end = args->va_start + size; addr < end;) { struct vm_area_struct *vma; unsigned long next; -- 2.20.1

...f --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index df9bf1fd1bc0b..3ec5da025bea7 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -171,6 +171,11 @@ nouveau_svmm_bind(struct drm_device *dev, void *data, mm = get_task_mm(current); down_read(&mm->mmap_sem); + if (!cli->svm.svmm) { + up_read(&mm->mmap_sem); + return -EINVAL; + } + for (addr = args->va_start, end = args->va_start + size; addr < end;) { struct vm_area_struct *vma; unsigned long next; -- 2.20.1

...f --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 668d4bd0c118f..25b7055949c45 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -173,6 +173,11 @@ nouveau_svmm_bind(struct drm_device *dev, void *data, mm = get_task_mm(current); down_read(&mm->mmap_sem); + if (!cli->svm.svmm) { + up_read(&mm->mmap_sem); + return -EINVAL; + } + for (addr = args->va_start, end = args->va_start + size; addr < end;) { struct vm_area_struct *vma; unsigned long next; -- 2.20.1

...f (dev->mm) { err = -EBUSY; goto err_mm; } We've changed the code but didn't update the label so it's slightly confusing unless you know how vhost_dev_has_owner() is implemented. 483 } 484 485 /* No owner, become one */ 486 dev->mm = get_task_mm(current); 487 worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); 488 if (IS_ERR(worker)) { 489 err = PTR_ERR(worker); 490 goto err_worker; 491 } 492 493 dev->worker = work...

...at all. > work->fn(work); > +#ifdef CONFIG_KCOV > + kcov_remote_stop(); > +#endif > if (need_resched()) > schedule(); > } > @@ -546,6 +552,9 @@ long vhost_dev_set_owner(struct vhost_dev *dev) > > /* No owner, become one */ > dev->mm = get_task_mm(current); > +#ifdef CONFIG_KCOV > + dev->kcov_handle = current->kcov_handle; > +#endif > worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); > if (IS_ERR(worker)) { > err = PTR_ERR(worker); > @@ -571,6 +580,9 @@ long vhost_dev_set_own...

...kcov_remote_stop(); > if (need_resched()) > schedule(); > } > @@ -546,6 +549,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev) > > /* No owner, become one */ > dev->mm = get_task_mm(current); > + dev->kcov_handle = current->kcov_handle; kcov_handle is not present in task_struct if !CONFIG_KCOV Also this does not use KCOV_SUBSYSTEM_COMMON. We discussed something along the following lines: u64 kcov_remote_handle(u64 subsys, u64 id) { WARN_ON(subsys or id has...

...if (need_resched()) > > > schedule(); > > > } > > > @@ -546,6 +549,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev) > > > > > > /* No owner, become one */ > > > dev->mm = get_task_mm(current); > > > + dev->kcov_handle = current->kcov_handle; > > > > kcov_handle is not present in task_struct if !CONFIG_KCOV > > > > Also this does not use KCOV_SUBSYSTEM_COMMON. > > We discussed something along the following lines: > > >...

...ent made it, just at the store side: > > /* > * Serialize the update against mmu_notifier_unregister. A > * side note: mmu_notifier_release can't run concurrently with > * us because we hold the mm_users pin (either implicitly as > * current->mm or explicitly with get_task_mm() or similar). > * We can't race against any other mmu notifier method either > * thanks to mm_take_all_locks(). > * > * release semantics on the initialization of the mmu_notifier_mm's > * contents are provided for unlocked readers. acquire can only be >...

...t;byte_weight = byte_weight; + dev->use_worker = use_worker; dev->msg_handler = msg_handler; init_llist_head(&dev->work_list); init_waitqueue_head(&dev->wait); @@ -549,18 +556,21 @@ long vhost_dev_set_owner(struct vhost_dev *dev) /* No owner, become one */ dev->mm = get_task_mm(current); dev->kcov_handle = kcov_common_handle(); - worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); - if (IS_ERR(worker)) { - err = PTR_ERR(worker); - goto err_worker; - } + if (dev->use_worker) { + worker = kthread_create(vhost_worker, dev, + &quo...

...managed by the @@ -335,24 +354,33 @@ nouveau_svmm_init(struct drm_device *dev, void *data, .fault_replay = true, }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm); if (ret) - goto done; + goto out_free; - /* Enable HMM mirroring of CPU address-space to VMM. */ - svmm->mm = get_task_mm(current); - down_write(&svmm->mm->mmap_sem); + down_write(&current->mm->mmap_sem); svmm->mirror.ops = &nouveau_svmm; - ret = hmm_mirror_register(&svmm->mirror, svmm->mm); - if (ret == 0) { - cli->svm.svmm = svmm; - cli->svm.cli = cli; - } - up_write(&a...

...gt; - INIT_LIST_HEAD(&priv->freeable_maps); > mutex_init(&priv->lock); > > #ifdef CONFIG_XEN_GNTDEV_DMABUF > @@ -606,17 +525,6 @@ static int gntdev_open(struct inode *inode, struct file *flip) > } > #endif > > - if (use_ptemod) { > - priv->mm = get_task_mm(current); > - if (!priv->mm) { > - kfree(priv); > - return -ENOMEM; > - } > - priv->mn.ops = &gntdev_mmu_ops; > - ret = mmu_notifier_register(&priv->mn, priv->mm); > - mmput(priv->mm); > - } > - > if (ret) { > kfree(priv); >...

Hi all: This series introduce basic functionality of doorbell mapping support for vhost-vDPA. Userspace program may use mmap() to map a the doorbell of a specific virtqueue into its address space. This is help to reudce the syscall or vmexit overhead. A new vdpa_config_ops was introduced to report the location of the doorbell, vhost_vdpa may then choose to map the doorbell when: - The doorbell

Hi all: This series introduce basic functionality of doorbell mapping support for vhost-vDPA. Userspace program may use mmap() to map a the doorbell of a specific virtqueue into its address space. This is help to reudce the syscall or vmexit overhead. A new vdpa_config_ops was introduced to report the location of the doorbell, vhost_vdpa may then choose to map the doorbell when: - The doorbell