vDPA/ifcvf: detect and use the onboard number of queues directly

To enable this multi-queue feature for ifcvf, this commit
intends to detect and use the onboard number of queues
directly than IFCVF_MAX_QUEUE_PAIRS = 1 (removed)

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20210818095714.3220-2-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

drivers/vdpa/ifcvf/ifcvf_base.c

@@ -158,7 +158,9 @@ next:
 		return -EIO;
 	}
 
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+	hw->nr_vring = ifc_ioread16(&hw->common_cfg->num_queues);
+
+	for (i = 0; i < hw->nr_vring; i++) {
 		ifc_iowrite16(i, &hw->common_cfg->queue_select);
 		notify_off = ifc_ioread16(&hw->common_cfg->queue_notify_off);
 		hw->vring[i].notify_addr = hw->notify_base +
@@ -304,7 +306,7 @@ u16 ifcvf_get_vq_state(struct ifcvf_hw *hw, u16 qid)
 	u32 q_pair_id;
 
 	ifcvf_lm = (struct ifcvf_lm_cfg __iomem *)hw->lm_cfg;
-	q_pair_id = qid / (IFCVF_MAX_QUEUE_PAIRS * 2);
+	q_pair_id = qid / hw->nr_vring;
 	avail_idx_addr = &ifcvf_lm->vring_lm_cfg[q_pair_id].idx_addr[qid % 2];
 	last_avail_idx = ifc_ioread16(avail_idx_addr);
 
@@ -318,7 +320,7 @@ int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num)
 	u32 q_pair_id;
 
 	ifcvf_lm = (struct ifcvf_lm_cfg __iomem *)hw->lm_cfg;
-	q_pair_id = qid / (IFCVF_MAX_QUEUE_PAIRS * 2);
+	q_pair_id = qid / hw->nr_vring;
 	avail_idx_addr = &ifcvf_lm->vring_lm_cfg[q_pair_id].idx_addr[qid % 2];
 	hw->vring[qid].last_avail_idx = num;
 	ifc_iowrite16(num, avail_idx_addr);

drivers/vdpa/ifcvf/ifcvf_base.h

@@ -31,8 +31,8 @@
 		 (1ULL << VIRTIO_F_ACCESS_PLATFORM)		| \
 		 (1ULL << VIRTIO_NET_F_MRG_RXBUF))
 
-/* Only one queue pair for now. */
-#define IFCVF_MAX_QUEUE_PAIRS	1
+/* Max 8 data queue pairs(16 queues) and one control vq for now. */
+#define IFCVF_MAX_QUEUES	17
 
 #define IFCVF_QUEUE_ALIGNMENT	PAGE_SIZE
 #define IFCVF_QUEUE_MAX		32768
@@ -51,8 +51,6 @@
 #define ifcvf_private_to_vf(adapter) \
 	(&((struct ifcvf_adapter *)adapter)->vf)
 
-#define IFCVF_MAX_INTR (IFCVF_MAX_QUEUE_PAIRS * 2 + 1)
-
 struct vring_info {
 	u64 desc;
 	u64 avail;
@@ -83,7 +81,7 @@ struct ifcvf_hw {
 	u32 dev_type;
 	struct virtio_pci_common_cfg __iomem *common_cfg;
 	void __iomem *net_cfg;
-	struct vring_info vring[IFCVF_MAX_QUEUE_PAIRS * 2];
+	struct vring_info vring[IFCVF_MAX_QUEUES];
 	void __iomem * const *base;
 	char config_msix_name[256];
 	struct vdpa_callback config_cb;
@@ -103,7 +101,7 @@ struct ifcvf_vring_lm_cfg {
 
 struct ifcvf_lm_cfg {
 	u8 reserved[IFCVF_LM_RING_STATE_OFFSET];
-	struct ifcvf_vring_lm_cfg vring_lm_cfg[IFCVF_MAX_QUEUE_PAIRS];
+	struct ifcvf_vring_lm_cfg vring_lm_cfg[IFCVF_MAX_QUEUES];
 };
 
 struct ifcvf_vdpa_mgmt_dev {

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -63,9 +63,13 @@ static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
 	struct pci_dev *pdev = adapter->pdev;
 	struct ifcvf_hw *vf = &adapter->vf;
 	int vector, i, ret, irq;
+	u16 max_intr;
 
-	ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR,
-				    IFCVF_MAX_INTR, PCI_IRQ_MSIX);
+	/* all queues and config interrupt  */
+	max_intr = vf->nr_vring + 1;
+
+	ret = pci_alloc_irq_vectors(pdev, max_intr,
+				    max_intr, PCI_IRQ_MSIX);
 	if (ret < 0) {
 		IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n");
 		return ret;
@@ -83,7 +87,7 @@ static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
 		return ret;
 	}
 
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+	for (i = 0; i < vf->nr_vring; i++) {
 		snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n",
 			 pci_name(pdev), i);
 		vector = i + IFCVF_MSI_QUEUE_OFF;
@@ -112,7 +116,6 @@ static int ifcvf_start_datapath(void *private)
 	u8 status;
 	int ret;
 
-	vf->nr_vring = IFCVF_MAX_QUEUE_PAIRS * 2;
 	ret = ifcvf_start_hw(vf);
 	if (ret < 0) {
 		status = ifcvf_get_status(vf);
@@ -128,7 +131,7 @@ static int ifcvf_stop_datapath(void *private)
 	struct ifcvf_hw *vf = ifcvf_private_to_vf(private);
 	int i;
 
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++)
+	for (i = 0; i < vf->nr_vring; i++)
 		vf->vring[i].cb.callback = NULL;
 
 	ifcvf_stop_hw(vf);
@@ -141,7 +144,7 @@ static void ifcvf_reset_vring(struct ifcvf_adapter *adapter)
 	struct ifcvf_hw *vf = ifcvf_private_to_vf(adapter);
 	int i;
 
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+	for (i = 0; i < vf->nr_vring; i++) {
 		vf->vring[i].last_avail_idx = 0;
 		vf->vring[i].desc = 0;
 		vf->vring[i].avail = 0;
@@ -227,7 +230,7 @@ static void ifcvf_vdpa_set_status(struct vdpa_device *vdpa_dev, u8 status)
 	if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) &&
 	    !(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 		ifcvf_stop_datapath(adapter);
-		ifcvf_free_irq(adapter, IFCVF_MAX_QUEUE_PAIRS * 2);
+		ifcvf_free_irq(adapter, vf->nr_vring);
 	}
 
 	if (status == 0) {
@@ -526,13 +529,13 @@ static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
 		goto err;
 	}
 
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++)
+	for (i = 0; i < vf->nr_vring; i++)
 		vf->vring[i].irq = -EINVAL;
 
 	vf->hw_features = ifcvf_get_hw_features(vf);
 
 	adapter->vdpa.mdev = &ifcvf_mgmt_dev->mdev;
-	ret = _vdpa_register_device(&adapter->vdpa, IFCVF_MAX_QUEUE_PAIRS * 2);
+	ret = _vdpa_register_device(&adapter->vdpa, vf->nr_vring);
 	if (ret) {
 		IFCVF_ERR(pdev, "Failed to register to vDPA bus");
 		goto err;