Messages in this thread Patch in this message | | | From | "Longpeng(Mike)" <> | Subject | [PATCH v4 2/2] vdpasim: support doorbell mapping | Date | Mon, 27 Feb 2023 17:18:57 +0800 |
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From: Longpeng <longpeng2@huawei.com>
Support doorbell mapping for vdpasim devices, then we can test the notify passthrough feature even if there's no real hardware on hand.
Allocates a dummy page which is used to emulate the notify page of the device, all VQs share the same notify register that initiated to 0xffff. A periodic work will check whether there're requests need to process ( the value of the notify register is 0xffff or not ).
We can test on QEMU with: -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0,page-per-vq=on
Signed-off-by: Longpeng <longpeng2@huawei.com> --- drivers/vdpa/vdpa_sim/vdpa_sim.c | 67 ++++++++++++++++++++++++++++++++ drivers/vdpa/vdpa_sim/vdpa_sim.h | 3 ++ 2 files changed, 70 insertions(+)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index cb88891b44a8..5a8c820b179f 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -39,6 +39,8 @@ MODULE_PARM_DESC(max_iotlb_entries, #define VDPASIM_QUEUE_ALIGN PAGE_SIZE #define VDPASIM_QUEUE_MAX 256 #define VDPASIM_VENDOR_ID 0 +#define VDPASIM_VRING_POLL_PERIOD 100 /* ms */ +#define VDPASIM_NOTIFY_DEFVAL 0xffff static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa) { @@ -245,6 +247,28 @@ static const struct dma_map_ops vdpasim_dma_ops = { static const struct vdpa_config_ops vdpasim_config_ops; static const struct vdpa_config_ops vdpasim_batch_config_ops; +static void vdpasim_notify_work(struct work_struct *work) +{ + struct vdpasim *vdpasim; + u16 *val; + + vdpasim = container_of(work, struct vdpasim, notify_work.work); + + if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK)) + goto out; + + if (!vdpasim->running) + goto out; + + val = (u16 *)vdpasim->notify; + if (xchg(val, VDPASIM_NOTIFY_DEFVAL) != VDPASIM_NOTIFY_DEFVAL) + schedule_work(&vdpasim->work); + +out: + schedule_delayed_work(&vdpasim->notify_work, + msecs_to_jiffies(VDPASIM_VRING_POLL_PERIOD)); +} + struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, const struct vdpa_dev_set_config *config) { @@ -286,6 +310,13 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, set_dma_ops(dev, &vdpasim_dma_ops); vdpasim->vdpa.mdev = dev_attr->mgmt_dev; + INIT_DELAYED_WORK(&vdpasim->notify_work, vdpasim_notify_work); + + vdpasim->notify = (u16 *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!vdpasim->notify) + goto err_iommu; + WRITE_ONCE(*vdpasim->notify, VDPASIM_NOTIFY_DEFVAL); + vdpasim->config = kzalloc(dev_attr->config_size, GFP_KERNEL); if (!vdpasim->config) goto err_iommu; @@ -320,6 +351,13 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, vdpasim->vdpa.dma_dev = dev; + /* + * Start periodic (every 100ms) notify work, it won't introduce + * any overhead if the device is not started. + */ + schedule_delayed_work(&vdpasim->notify_work, + msecs_to_jiffies(VDPASIM_VRING_POLL_PERIOD)); + return vdpasim; err_iommu: @@ -671,11 +709,34 @@ static int vdpasim_dma_unmap(struct vdpa_device *vdpa, unsigned int asid, return 0; } +static pgprot_t vdpasim_get_vq_notification_pgprot(struct vdpa_device *vdpa, + u16 qid, pgprot_t prot) +{ + /* + * We use normal RAM pages to emulate the vq notification area, so + * just keep the pgprot as it mmaped. + */ + return prot; +} + +static struct vdpa_notification_area +vdpasim_get_vq_notification(struct vdpa_device *vdpa, u16 qid) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + struct vdpa_notification_area notify; + + notify.addr = virt_to_phys((void *)vdpasim->notify); + notify.size = PAGE_SIZE; + + return notify; +} + static void vdpasim_free(struct vdpa_device *vdpa) { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); int i; + cancel_delayed_work_sync(&vdpasim->notify_work); cancel_work_sync(&vdpasim->work); for (i = 0; i < vdpasim->dev_attr.nvqs; i++) { @@ -694,6 +755,8 @@ static void vdpasim_free(struct vdpa_device *vdpa) kfree(vdpasim->iommu); kfree(vdpasim->vqs); kfree(vdpasim->config); + if (vdpasim->notify) + free_page((unsigned long)vdpasim->notify); } static const struct vdpa_config_ops vdpasim_config_ops = { @@ -705,6 +768,8 @@ static const struct vdpa_config_ops vdpasim_config_ops = { .get_vq_ready = vdpasim_get_vq_ready, .set_vq_state = vdpasim_set_vq_state, .get_vq_state = vdpasim_get_vq_state, + .get_vq_notification = vdpasim_get_vq_notification, + .get_vq_notification_pgprot = vdpasim_get_vq_notification_pgprot, .get_vq_align = vdpasim_get_vq_align, .get_vq_group = vdpasim_get_vq_group, .get_device_features = vdpasim_get_device_features, @@ -738,6 +803,8 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = { .get_vq_ready = vdpasim_get_vq_ready, .set_vq_state = vdpasim_set_vq_state, .get_vq_state = vdpasim_get_vq_state, + .get_vq_notification = vdpasim_get_vq_notification, + .get_vq_notification_pgprot = vdpasim_get_vq_notification_pgprot, .get_vq_align = vdpasim_get_vq_align, .get_vq_group = vdpasim_get_vq_group, .get_device_features = vdpasim_get_device_features, diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h index 0e78737dcc16..786e902de0b2 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h @@ -69,6 +69,9 @@ struct vdpasim { bool running; /* spinlock to synchronize iommu table */ spinlock_t iommu_lock; + /* dummy notify page */ + u16 *notify; + struct delayed_work notify_work; }; struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *attr, -- 2.23.0
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