[PATCH] vduse: Add suspend
From: Eugenio Pérez
Date: Wed Feb 11 2026 - 07:02:53 EST
Implement suspend operation for vduse devices, so vhost-vdpa will offer
that backend feature and userspace can effectively suspend the device.
This is a must before get virtqueue indexes (base) for live migration,
since the device could modify them after userland gets them.
Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
---
This series depends on
https://lore.kernel.org/lkml/20260210082554.1582553-1-eperezma@xxxxxxxxxx
---
drivers/vdpa/vdpa_user/vduse_dev.c | 86 +++++++++++++++++++++++++++++-
include/uapi/linux/vduse.h | 4 ++
2 files changed, 88 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 59d9c4718d86..bdcc114e2710 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -54,7 +54,8 @@
#define IRQ_UNBOUND -1
/* Supported VDUSE features */
-static const uint64_t vduse_features = BIT_U64(VDUSE_F_QUEUE_READY);
+static const uint64_t vduse_features = BIT_U64(VDUSE_F_QUEUE_READY) |
+ BIT_U64(VDUSE_F_SUSPEND);
/*
* VDUSE instance have not asked the vduse API version, so assume 0.
@@ -85,6 +86,7 @@ struct vduse_virtqueue {
int irq_effective_cpu;
struct cpumask irq_affinity;
struct kobject kobj;
+ struct vduse_dev *dev;
};
struct vduse_dev;
@@ -134,6 +136,7 @@ struct vduse_dev {
int minor;
bool broken;
bool connected;
+ bool suspended;
u64 api_version;
u64 device_features;
u64 driver_features;
@@ -480,6 +483,7 @@ static void vduse_dev_reset(struct vduse_dev *dev)
down_write(&dev->rwsem);
+ dev->suspended = false;
dev->status = 0;
dev->driver_features = 0;
dev->generation++;
@@ -559,6 +563,10 @@ static void vduse_vdpa_kick_vq(struct vdpa_device *vdpa, u16 idx)
struct vduse_dev *dev = vdpa_to_vduse(vdpa);
struct vduse_virtqueue *vq = dev->vqs[idx];
+ guard(rwsem_read)(&vq->dev->rwsem);
+ if (vq->dev->suspended)
+ return;
+
if (!eventfd_signal_allowed()) {
schedule_work(&vq->kick);
return;
@@ -896,6 +904,27 @@ static int vduse_vdpa_set_map(struct vdpa_device *vdpa,
return 0;
}
+static int vduse_vdpa_suspend(struct vdpa_device *vdpa)
+{
+ struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+ struct vduse_dev_msg msg = { 0 };
+ int ret;
+
+ msg.req.type = VDUSE_SUSPEND;
+
+ ret = vduse_dev_msg_sync(dev, &msg);
+ if (ret == 0) {
+ scoped_guard(rwsem_write, &dev->rwsem)
+ dev->suspended = true;
+
+ cancel_work_sync(&dev->inject);
+ for (u32 i = 0; i < dev->vq_num; i++)
+ cancel_work_sync(&dev->vqs[i]->inject);
+ }
+
+ return ret;
+}
+
static void vduse_vdpa_free(struct vdpa_device *vdpa)
{
struct vduse_dev *dev = vdpa_to_vduse(vdpa);
@@ -937,6 +966,41 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
.free = vduse_vdpa_free,
};
+static const struct vdpa_config_ops vduse_vdpa_config_ops_with_suspend = {
+ .set_vq_address = vduse_vdpa_set_vq_address,
+ .kick_vq = vduse_vdpa_kick_vq,
+ .set_vq_cb = vduse_vdpa_set_vq_cb,
+ .set_vq_num = vduse_vdpa_set_vq_num,
+ .get_vq_size = vduse_vdpa_get_vq_size,
+ .get_vq_group = vduse_get_vq_group,
+ .set_vq_ready = vduse_vdpa_set_vq_ready,
+ .get_vq_ready = vduse_vdpa_get_vq_ready,
+ .set_vq_state = vduse_vdpa_set_vq_state,
+ .get_vq_state = vduse_vdpa_get_vq_state,
+ .get_vq_align = vduse_vdpa_get_vq_align,
+ .get_device_features = vduse_vdpa_get_device_features,
+ .set_driver_features = vduse_vdpa_set_driver_features,
+ .get_driver_features = vduse_vdpa_get_driver_features,
+ .set_config_cb = vduse_vdpa_set_config_cb,
+ .get_vq_num_max = vduse_vdpa_get_vq_num_max,
+ .get_device_id = vduse_vdpa_get_device_id,
+ .get_vendor_id = vduse_vdpa_get_vendor_id,
+ .get_status = vduse_vdpa_get_status,
+ .set_status = vduse_vdpa_set_status,
+ .get_config_size = vduse_vdpa_get_config_size,
+ .get_config = vduse_vdpa_get_config,
+ .set_config = vduse_vdpa_set_config,
+ .get_generation = vduse_vdpa_get_generation,
+ .set_vq_affinity = vduse_vdpa_set_vq_affinity,
+ .get_vq_affinity = vduse_vdpa_get_vq_affinity,
+ .reset = vduse_vdpa_reset,
+ .set_map = vduse_vdpa_set_map,
+ .set_group_asid = vduse_set_group_asid,
+ .get_vq_map = vduse_get_vq_map,
+ .suspend = vduse_vdpa_suspend,
+ .free = vduse_vdpa_free,
+};
+
static void vduse_dev_sync_single_for_device(union virtio_map token,
dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
@@ -1148,6 +1212,10 @@ static void vduse_dev_irq_inject(struct work_struct *work)
{
struct vduse_dev *dev = container_of(work, struct vduse_dev, inject);
+ guard(rwsem_read)(&dev->rwsem);
+ if (dev->suspended)
+ return;
+
spin_lock_bh(&dev->irq_lock);
if (dev->config_cb.callback)
dev->config_cb.callback(dev->config_cb.private);
@@ -1159,6 +1227,10 @@ static void vduse_vq_irq_inject(struct work_struct *work)
struct vduse_virtqueue *vq = container_of(work,
struct vduse_virtqueue, inject);
+ guard(rwsem_read)(&vq->dev->rwsem);
+ if (vq->dev->suspended)
+ return;
+
spin_lock_bh(&vq->irq_lock);
if (vq->ready && vq->cb.callback)
vq->cb.callback(vq->cb.private);
@@ -1189,6 +1261,9 @@ static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
int ret = -EINVAL;
down_read(&dev->rwsem);
+ if (dev->suspended)
+ return ret;
+
if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto unlock;
@@ -1839,6 +1914,7 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num)
}
dev->vqs[i]->index = i;
+ dev->vqs[i]->dev = dev;
dev->vqs[i]->irq_effective_cpu = IRQ_UNBOUND;
INIT_WORK(&dev->vqs[i]->inject, vduse_vq_irq_inject);
INIT_WORK(&dev->vqs[i]->kick, vduse_vq_kick_work);
@@ -2311,12 +2387,18 @@ static struct vduse_mgmt_dev *vduse_mgmt;
static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
{
struct vduse_vdpa *vdev;
+ const struct vdpa_config_ops *ops;
if (dev->vdev)
return -EEXIST;
+ if (dev->vduse_features & BIT_U64(VDUSE_F_SUSPEND))
+ ops = &vduse_vdpa_config_ops_with_suspend;
+ else
+ ops = &vduse_vdpa_config_ops;
+
vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
- &vduse_vdpa_config_ops, &vduse_map_ops,
+ ops, &vduse_map_ops,
dev->ngroups, dev->nas, name, true);
if (IS_ERR(vdev))
return PTR_ERR(vdev);
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index d39734cef6d3..95b93bc6bac5 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -21,6 +21,9 @@
/* The VDUSE instance expects a request for vq ready */
#define VDUSE_F_QUEUE_READY 0
+/* The VDUSE instance expects a request for suspend */
+#define VDUSE_F_SUSPEND 1
+
/*
* Get the version of VDUSE API that kernel supported (VDUSE_API_VERSION).
* This is used for future extension.
@@ -338,6 +341,7 @@ enum vduse_req_type {
VDUSE_UPDATE_IOTLB,
VDUSE_SET_VQ_GROUP_ASID,
VDUSE_SET_VQ_READY,
+ VDUSE_SUSPEND,
};
/**
--
2.53.0