The new "use_va" module parameter (default: false) is used in
vdpa_alloc_device() to inform the vDPA framework that the device
supports VA.
vringh is initialized to use VA only when "use_va" is true and the
user's mm has been bound. So, only when the bus supports user VA
(e.g. vhost-vdpa).
vdpasim_mm_work_fn work is used to attach the kthread to the user
address space when the .bind_mm callback is invoked, and to detach
it when the device is reset.
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
drivers/vdpa/vdpa_sim/vdpa_sim.c | 104 ++++++++++++++++++++++++++++++-
2 files changed, 103 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
index 07ef53ea375e..1b010e5c0445 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
@@ -55,6 +55,7 @@ struct vdpasim {
struct vdpasim_virtqueue *vqs;
struct kthread_worker *worker;
struct kthread_work work;
+ struct mm_struct *mm_bound;
struct vdpasim_dev_attr dev_attr;
/* spinlock to synchronize virtqueue state */
spinlock_t lock;
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 36a1d2e0a6ba..6e07cedef30c 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -36,10 +36,90 @@ module_param(max_iotlb_entries, int, 0444);
MODULE_PARM_DESC(max_iotlb_entries,
"Maximum number of iotlb entries for each address space. 0 means unlimited. (default: 2048)");
+static bool use_va;
+module_param(use_va, bool, 0444);
+MODULE_PARM_DESC(use_va, "Enable the device's ability to use VA");
+
#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
#define VDPASIM_QUEUE_MAX 256
#define VDPASIM_VENDOR_ID 0
+struct vdpasim_mm_work {
+ struct kthread_work work;
+ struct task_struct *owner;
+ struct mm_struct *mm;
+ bool bind;
+ int ret;
+};
+
+static void vdpasim_mm_work_fn(struct kthread_work *work)
+{
+ struct vdpasim_mm_work *mm_work =
+ container_of(work, struct vdpasim_mm_work, work);
+
+ mm_work->ret = 0;
+
+ if (mm_work->bind) {
+ kthread_use_mm(mm_work->mm);
+#if 0
+ if (mm_work->owner)
+ mm_work->ret = cgroup_attach_task_all(mm_work->owner,
+ current);
+#endif
+ } else {
+#if 0
+ //TODO: check it
+ cgroup_release(current);
+#endif
+ kthread_unuse_mm(mm_work->mm);
+ }
+}
+
+static void vdpasim_worker_queue_mm(struct vdpasim *vdpasim,
+ struct vdpasim_mm_work *mm_work)
+{
+ struct kthread_work *work = &mm_work->work;
+
+ kthread_init_work(work, vdpasim_mm_work_fn);
+ kthread_queue_work(vdpasim->worker, work);
+
+ spin_unlock(&vdpasim->lock);
+ kthread_flush_work(work);
+ spin_lock(&vdpasim->lock);
+}
+
+static int vdpasim_worker_bind_mm(struct vdpasim *vdpasim,
+ struct mm_struct *new_mm,
+ struct task_struct *owner)
+{
+ struct vdpasim_mm_work mm_work;
+
+ mm_work.owner = owner;
+ mm_work.mm = new_mm;
+ mm_work.bind = true;
+
+ vdpasim_worker_queue_mm(vdpasim, &mm_work);
+
+ if (!mm_work.ret)
+ vdpasim->mm_bound = new_mm;
+
+ return mm_work.ret;
+}
+
+static void vdpasim_worker_unbind_mm(struct vdpasim *vdpasim)
+{
+ struct vdpasim_mm_work mm_work;
+
+ if (!vdpasim->mm_bound)
+ return;
+
+ mm_work.mm = vdpasim->mm_bound;
+ mm_work.bind = false;
+
+ vdpasim_worker_queue_mm(vdpasim, &mm_work);
+
+ vdpasim->mm_bound = NULL;
+}
static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
{
return container_of(vdpa, struct vdpasim, vdpa);
@@ -66,8 +146,10 @@ static void vdpasim_vq_notify(struct vringh *vring)
static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
{
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+ bool va_enabled = use_va && vdpasim->mm_bound;
- vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false, false,
+ vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false,
+ va_enabled,
(struct vring_desc *)(uintptr_t)vq->desc_addr,
(struct vring_avail *)
(uintptr_t)vq->driver_addr,
@@ -96,6 +178,9 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
{
int i;
+ //TODO: should we cancel the works?
+ vdpasim_worker_unbind_mm(vdpasim);
+
spin_lock(&vdpasim->iommu_lock);
for (i = 0; i < vdpasim->dev_attr.nvqs; i++) {
@@ -275,7 +360,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
dev_attr->ngroups, dev_attr->nas,
- dev_attr->name, false);
+ dev_attr->name, use_va);
if (IS_ERR(vdpasim)) {
ret = PTR_ERR(vdpasim);
goto err_alloc;
@@ -657,6 +742,19 @@ static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
return ret;
}
+static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct *mm,
+ struct task_struct *owner)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ int ret;
+
+ spin_lock(&vdpasim->lock);
+ ret = vdpasim_worker_bind_mm(vdpasim, mm, owner);
+ spin_unlock(&vdpasim->lock);
+
+ return ret;
+}
+
static int vdpasim_dma_map(struct vdpa_device *vdpa, unsigned int asid,
u64 iova, u64 size,
u64 pa, u32 perm, void *opaque)
@@ -744,6 +842,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
.set_group_asid = vdpasim_set_group_asid,
.dma_map = vdpasim_dma_map,
.dma_unmap = vdpasim_dma_unmap,
+ .bind_mm = vdpasim_bind_mm,
.free = vdpasim_free,
};
@@ -776,6 +875,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.get_iova_range = vdpasim_get_iova_range,
.set_group_asid = vdpasim_set_group_asid,
.set_map = vdpasim_set_map,
+ .bind_mm = vdpasim_bind_mm,
.free = vdpasim_free,
};
--
2.38.1
