[PATCH 6/6] vdpa: vp_vdpa: report doorbell location

From: Jason Wang
Date: Fri May 29 2020 - 04:04:28 EST


This patch adds support for reporting doorbell location in vp_vdpa
driver. The doorbell mapping could be then enabled by e.g launching
qemu's virtio-net-pci device with page-per-vq enabled.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/vdpa/vp_vdpa/vp_vdpa.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/vp_vdpa/vp_vdpa.c b/drivers/vdpa/vp_vdpa/vp_vdpa.c
index e59c310e2156..a5ca49533138 100644
--- a/drivers/vdpa/vp_vdpa/vp_vdpa.c
+++ b/drivers/vdpa/vp_vdpa/vp_vdpa.c
@@ -30,6 +30,7 @@
struct vp_vring {
void __iomem *notify;
char msix_name[256];
+ resource_size_t notify_pa;
struct vdpa_callback cb;
int irq;
};
@@ -136,7 +137,8 @@ static int find_capability(struct pci_dev *dev, u8 cfg_type,
return 0;
}

-static void __iomem *map_capability(struct vp_vdpa *vp_vdpa, int off)
+static void __iomem *map_capability(struct vp_vdpa *vp_vdpa, int off,
+ resource_size_t *pa)
{
struct pci_dev *pdev = vp_vdpa->pdev;
u32 offset;
@@ -149,6 +151,9 @@ static void __iomem *map_capability(struct vp_vdpa *vp_vdpa, int off)
off + offsetof(struct virtio_pci_cap, offset),
&offset);

+ if (pa)
+ *pa = pci_resource_start(pdev, bar) + offset;
+
return vp_vdpa->base[bar] + offset;
}

@@ -283,6 +288,18 @@ static u64 vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid)
return 0;
}

+static struct vdpa_notification_area
+vp_vdpa_get_vq_notification(struct vdpa_device *vdpa, u16 qid)
+{
+ struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
+ struct vdpa_notification_area notify;
+
+ notify.addr = vp_vdpa->vring[qid].notify_pa;
+ notify.size = vp_vdpa->notify_off_multiplier;
+
+ return notify;
+}
+
static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid,
u64 num)
{
@@ -423,6 +440,7 @@ static const struct vdpa_config_ops vp_vdpa_ops = {
.set_status = vp_vdpa_set_status,
.get_vq_num_max = vp_vdpa_get_vq_num_max,
.get_vq_state = vp_vdpa_get_vq_state,
+ .get_vq_notification = vp_vdpa_get_vq_notification,
.set_vq_state = vp_vdpa_set_vq_state,
.set_vq_cb = vp_vdpa_set_vq_cb,
.set_vq_ready = vp_vdpa_set_vq_ready,
@@ -445,6 +463,7 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
struct vp_vdpa *vp_vdpa;
int common, notify, device, ret, i;
struct virtio_device_id virtio_id;
+ resource_size_t notify_pa;
u16 notify_off;

/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
@@ -525,9 +544,9 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (ret)
dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");

- vp_vdpa->device = map_capability(vp_vdpa, device);
- vp_vdpa->notify = map_capability(vp_vdpa, notify);
- vp_vdpa->common = map_capability(vp_vdpa, common);
+ vp_vdpa->device = map_capability(vp_vdpa, device, NULL);
+ vp_vdpa->notify = map_capability(vp_vdpa, notify, &notify_pa);
+ vp_vdpa->common = map_capability(vp_vdpa, common, NULL);
vp_vdpa->id = virtio_id;

ret = vdpa_register_device(&vp_vdpa->vdpa);
@@ -545,6 +564,8 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
vp_vdpa->vring[i].irq = -1;
vp_vdpa->vring[i].notify = vp_vdpa->notify +
notify_off * vp_vdpa->notify_off_multiplier;
+ vp_vdpa->vring[i].notify_pa = notify_pa +
+ notify_off * vp_vdpa->notify_off_multiplier;
}

return 0;
--
2.20.1