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 <[email protected]> --- This series depends on https://lore.kernel.org/lkml/[email protected] --- 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
