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virtio: add VIRTIO_F_NOTIFICATION_DATA feature support

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According to VirtIO spec v1.2, VIRTIO_F_NOTIFICATION_DATA feature
indicates that the driver passes extra data along with the queue
notifications.

In a split queue case, the extra data is 16-bit available index. In a
packed queue case, the extra data is 1-bit wrap counter and 15-bit
available index.

Add support for this feature for MMIO, channel I/O and modern PCI
transports.

Signed-off-by: Viktor Prutyanov <viktor@daynix.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20230413081855.36643-2-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Viktor Prutyanov 2023-04-13 11:18:54 +03:00 committed by Michael S. Tsirkin
parent 3616bf377a
commit af8ececda1
6 changed files with 79 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/s390/virtio/virtio_ccw.c
View File

@ -391,7 +391,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
}
static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)
{
struct virtio_ccw_vq_info *info = vq->priv;
struct virtio_ccw_device *vcdev;
@ -402,12 +402,22 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
*((unsigned int *)&schid),
vq->index, info->cookie);
data, info->cookie);
if (info->cookie < 0)
return false;
return true;
}
static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
{
return virtio_ccw_do_kvm_notify(vq, vq->index);
}
static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)
{
return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));
}
static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
struct ccw1 *ccw, int index)
{
@ -495,6 +505,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
struct ccw1 *ccw)
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
bool (*notify)(struct virtqueue *vq);
int err;
struct virtqueue *vq = NULL;
struct virtio_ccw_vq_info *info;
@ -502,6 +513,11 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
unsigned long flags;
bool may_reduce;
if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
notify = virtio_ccw_kvm_notify_with_data;
else
notify = virtio_ccw_kvm_notify;
/* Allocate queue. */
info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
if (!info) {
@ -524,7 +540,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
may_reduce = vcdev->revision > 0;
vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
vdev, true, may_reduce, ctx,
virtio_ccw_kvm_notify, callback, name);
notify, callback, name);
if (!vq) {
/* For now, we fail if we can't get the requested size. */

18
drivers/virtio/virtio_mmio.c
View File

@ -285,6 +285,16 @@ static bool vm_notify(struct virtqueue *vq)
return true;
}
static bool vm_notify_with_data(struct virtqueue *vq)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
u32 data = vring_notification_data(vq);
writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
return true;
}
/* Notify all virtqueues on an interrupt. */
static irqreturn_t vm_interrupt(int irq, void *opaque)
{
@ -363,12 +373,18 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
const char *name, bool ctx)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
bool (*notify)(struct virtqueue *vq);
struct virtio_mmio_vq_info *info;
struct virtqueue *vq;
unsigned long flags;
unsigned int num;
int err;
if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
notify = vm_notify_with_data;
else
notify = vm_notify;
if (!name)
return NULL;
@ -397,7 +413,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
/* Create the vring */
vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
true, true, ctx, vm_notify, callback, name);
true, true, ctx, notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto error_new_virtqueue;

17
drivers/virtio/virtio_pci_modern.c
View File

@ -288,6 +288,15 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
return vp_modern_config_vector(&vp_dev->mdev, vector);
}
static bool vp_notify_with_data(struct virtqueue *vq)
{
u32 data = vring_notification_data(vq);
iowrite32(data, (void __iomem *)vq->priv);
return true;
}
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
struct virtio_pci_vq_info *info,
unsigned int index,
@ -298,10 +307,16 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
{
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
bool (*notify)(struct virtqueue *vq);
struct virtqueue *vq;
u16 num;
int err;
if (__virtio_test_bit(&vp_dev->vdev, VIRTIO_F_NOTIFICATION_DATA))
notify = vp_notify_with_data;
else
notify = vp_notify;
if (index >= vp_modern_get_num_queues(mdev))
return ERR_PTR(-EINVAL);
@ -316,7 +331,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
vq = vring_create_virtqueue(index, num,
SMP_CACHE_BYTES, &vp_dev->vdev,
true, true, ctx,
vp_notify, callback, name);
notify, callback, name);
if (!vq)
return ERR_PTR(-ENOMEM);

19
drivers/virtio/virtio_ring.c
View File

@ -2762,6 +2762,23 @@ void vring_del_virtqueue(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
u32 vring_notification_data(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 next;
if (vq->packed_ring)
next = (vq->packed.next_avail_idx &
~(-(1 << VRING_PACKED_EVENT_F_WRAP_CTR))) |
vq->packed.avail_wrap_counter <<
VRING_PACKED_EVENT_F_WRAP_CTR;
else
next = vq->split.avail_idx_shadow;
return next << 16 | _vq->index;
}
EXPORT_SYMBOL_GPL(vring_notification_data);
/* Manipulates transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev)
{
@ -2781,6 +2798,8 @@ void vring_transport_features(struct virtio_device *vdev)
break;
case VIRTIO_F_ORDER_PLATFORM:
break;
case VIRTIO_F_NOTIFICATION_DATA:
break;
default:
/* We don't understand this bit. */
__virtio_clear_bit(vdev, i);

2
include/linux/virtio_ring.h
View File

@ -117,4 +117,6 @@ void vring_del_virtqueue(struct virtqueue *vq);
void vring_transport_features(struct virtio_device *vdev);
irqreturn_t vring_interrupt(int irq, void *_vq);
u32 vring_notification_data(struct virtqueue *_vq);
#endif /* _LINUX_VIRTIO_RING_H */

6
include/uapi/linux/virtio_config.h
View File

@ -99,6 +99,12 @@
*/
#define VIRTIO_F_SR_IOV 37
/*
* This feature indicates that the driver passes extra data (besides
* identifying the virtqueue) in its device notifications.
*/
#define VIRTIO_F_NOTIFICATION_DATA 38
/*
* This feature indicates that the driver can reset a queue individually.
*/