Commit 9b3e8148 authored by Zhu Lingshan's avatar Zhu Lingshan Committed by Michael S. Tsirkin
Browse files

vDPA/ifcvf: implement shared IRQ feature 



On some platforms/devices, there may not be enough MSI vectors
allocated for the virtqueues and config changes. In such a case,
the interrupt sources(virtqueues, config changes) must share
an IRQ/vector, to avoid initialization failures, keep
the device functional.

This commit handles three cases:
(1) number of the allocated vectors == the number of virtqueues + 1
(config changes), every virtqueue and the config interrupt has
a separated vector/IRQ, the best and the most likely case.
(2) number of the allocated vectors is less than the best case, but
greater than 1. In this case, all virtqueues share a vector/IRQ,
the config interrupt has a separated vector/IRQ
(3) only one vector is allocated, in this case, the virtqueues and
the config interrupt share a vector/IRQ. The worst and most
unlikely case.

Otherwise, it needs to fail.

This commit introduces some helper functions:
ifcvf_set_vq_vector() and ifcvf_set_config_vector() sets virtqueue
vector and config vector in the device config space, so that
the device can send interrupt DMA.

Signed-off-by: default avatarZhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20220222115428.998334-5-lingshan.zhu@intel.com


Signed-off-by: default avatarTom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220315124130.1710030-1-trix@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent ad5c5690

drivers/vdpa/ifcvf/ifcvf_base.c

+26 −22
Original line number Diff line number Diff line
@@ -15,6 +15,26 @@ struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw) 
	return container_of(hw, struct ifcvf_adapter, vf);

}



u16 ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector)

{

	struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg;



	vp_iowrite16(qid, &cfg->queue_select);

	vp_iowrite16(vector, &cfg->queue_msix_vector);



	return vp_ioread16(&cfg->queue_msix_vector);

}



u16 ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector)

{

	struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg;



	cfg = hw->common_cfg;

	vp_iowrite16(vector,  &cfg->msix_config);



	return vp_ioread16(&cfg->msix_config);

}



static void __iomem *get_cap_addr(struct ifcvf_hw *hw,

				  struct virtio_pci_cap *cap)

{
@@ -131,6 +151,7 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct pci_dev *pdev) 
			notify_off * hw->notify_off_multiplier;

		hw->vring[i].notify_pa = hw->notify_base_pa +

			notify_off * hw->notify_off_multiplier;

		hw->vring[i].irq = -EINVAL;

	}



	hw->lm_cfg = hw->base[IFCVF_LM_BAR];
@@ -140,6 +161,9 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct pci_dev *pdev) 
		  hw->common_cfg, hw->notify_base, hw->isr,

		  hw->dev_cfg, hw->notify_off_multiplier);



	hw->vqs_reused_irq = -EINVAL;

	hw->config_irq = -EINVAL;



	return 0;

}
@@ -321,13 +345,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) 


	ifcvf = vf_to_adapter(hw);

	cfg = hw->common_cfg;

	vp_iowrite16(IFCVF_MSI_CONFIG_OFF, &cfg->msix_config);



	if (vp_ioread16(&cfg->msix_config) == VIRTIO_MSI_NO_VECTOR) {

		IFCVF_ERR(ifcvf->pdev, "No msix vector for device config\n");

		return -EINVAL;

	}



	for (i = 0; i < hw->nr_vring; i++) {

		if (!hw->vring[i].ready)

			break;
@@ -340,15 +357,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) 
		vp_iowrite64_twopart(hw->vring[i].used, &cfg->queue_used_lo,

				     &cfg->queue_used_hi);

		vp_iowrite16(hw->vring[i].size, &cfg->queue_size);

		vp_iowrite16(i + IFCVF_MSI_QUEUE_OFF, &cfg->queue_msix_vector);



		if (vp_ioread16(&cfg->queue_msix_vector) ==

		    VIRTIO_MSI_NO_VECTOR) {

			IFCVF_ERR(ifcvf->pdev,

				  "No msix vector for queue %u\n", i);

			return -EINVAL;

		}



		ifcvf_set_vq_state(hw, i, hw->vring[i].last_avail_idx);

		vp_iowrite16(1, &cfg->queue_enable);

	}
@@ -362,14 +370,10 @@ static void ifcvf_hw_disable(struct ifcvf_hw *hw) 
	u32 i;



	cfg = hw->common_cfg;

	vp_iowrite16(VIRTIO_MSI_NO_VECTOR, &cfg->msix_config);



	ifcvf_set_config_vector(hw, VIRTIO_MSI_NO_VECTOR);

	for (i = 0; i < hw->nr_vring; i++) {

		vp_iowrite16(i, &cfg->queue_select);

		vp_iowrite16(VIRTIO_MSI_NO_VECTOR, &cfg->queue_msix_vector);

		ifcvf_set_vq_vector(hw, i, VIRTIO_MSI_NO_VECTOR);

	}



	vp_ioread16(&cfg->queue_msix_vector);

}



int ifcvf_start_hw(struct ifcvf_hw *hw)

drivers/vdpa/ifcvf/ifcvf_base.h

+12 −3
Original line number Diff line number Diff line
@@ -28,8 +28,6 @@ 


#define IFCVF_QUEUE_ALIGNMENT	PAGE_SIZE

#define IFCVF_QUEUE_MAX		32768

#define IFCVF_MSI_CONFIG_OFF	0

#define IFCVF_MSI_QUEUE_OFF	1

#define IFCVF_PCI_MAX_RESOURCE	6



#define IFCVF_LM_CFG_SIZE		0x40
@@ -43,6 +41,13 @@ 
#define ifcvf_private_to_vf(adapter) \

	(&((struct ifcvf_adapter *)adapter)->vf)



/* all vqs and config interrupt has its own vector */

#define MSIX_VECTOR_PER_VQ_AND_CONFIG		1

/* all vqs share a vector, and config interrupt has a separate vector */

#define MSIX_VECTOR_SHARED_VQ_AND_CONFIG	2

/* all vqs and config interrupt share a vector */

#define MSIX_VECTOR_DEV_SHARED			3



struct vring_info {

	u64 desc;

	u64 avail;
@@ -77,9 +82,11 @@ struct ifcvf_hw { 
	void __iomem * const *base;

	char config_msix_name[256];

	struct vdpa_callback config_cb;

	unsigned int config_irq;

	int config_irq;

	int vqs_reused_irq;

	/* virtio-net or virtio-blk device config size */

	u32 config_size;

	u8 msix_vector_status;

};



struct ifcvf_adapter {
@@ -124,4 +131,6 @@ int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num); 
struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw);

int ifcvf_probed_virtio_net(struct ifcvf_hw *hw);

u32 ifcvf_get_config_size(struct ifcvf_hw *hw);

u16 ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector);

u16 ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector);

#endif /* _IFCVF_H_ */

drivers/vdpa/ifcvf/ifcvf_main.c

+262 −32
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ static irqreturn_t ifcvf_config_changed(int irq, void *arg) 
	return IRQ_HANDLED;

}



static irqreturn_t ifcvf_intr_handler(int irq, void *arg)

static irqreturn_t ifcvf_vq_intr_handler(int irq, void *arg)

{

	struct vring_info *vring = arg;
@@ -37,24 +37,98 @@ static irqreturn_t ifcvf_intr_handler(int irq, void *arg) 
	return IRQ_HANDLED;

}



static irqreturn_t ifcvf_vqs_reused_intr_handler(int irq, void *arg)

{

	struct ifcvf_hw *vf = arg;

	struct vring_info *vring;

	int i;



	for (i = 0; i < vf->nr_vring; i++) {

		vring = &vf->vring[i];

		if (vring->cb.callback)

			vring->cb.callback(vring->cb.private);

	}



	return IRQ_HANDLED;

}



static irqreturn_t ifcvf_dev_intr_handler(int irq, void *arg)

{

	struct ifcvf_hw *vf = arg;

	u8 isr;



	isr = vp_ioread8(vf->isr);

	if (isr & VIRTIO_PCI_ISR_CONFIG)

		ifcvf_config_changed(irq, arg);



	return ifcvf_vqs_reused_intr_handler(irq, arg);

}



static void ifcvf_free_irq_vectors(void *data)

{

	pci_free_irq_vectors(data);

}



static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues)

static void ifcvf_free_per_vq_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;

	int i;





	for (i = 0; i < queues; i++) {

	for (i = 0; i < vf->nr_vring; i++) {

		if (vf->vring[i].irq != -EINVAL) {

			devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]);

			vf->vring[i].irq = -EINVAL;

		}

	}

}



static void ifcvf_free_vqs_reused_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;



	if (vf->vqs_reused_irq != -EINVAL) {

		devm_free_irq(&pdev->dev, vf->vqs_reused_irq, vf);

		vf->vqs_reused_irq = -EINVAL;

	}



}



static void ifcvf_free_vq_irq(struct ifcvf_adapter *adapter)

{

	struct ifcvf_hw *vf = &adapter->vf;



	if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG)

		ifcvf_free_per_vq_irq(adapter);

	else

		ifcvf_free_vqs_reused_irq(adapter);

}



static void ifcvf_free_config_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;



	if (vf->config_irq == -EINVAL)

		return;



	/* If the irq is shared by all vqs and the config interrupt,

	 * it is already freed in ifcvf_free_vq_irq, so here only

	 * need to free config irq when msix_vector_status != MSIX_VECTOR_DEV_SHARED

	 */

	if (vf->msix_vector_status != MSIX_VECTOR_DEV_SHARED) {

		devm_free_irq(&pdev->dev, vf->config_irq, vf);

		vf->config_irq = -EINVAL;

	}

}



static void ifcvf_free_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;



	ifcvf_free_vq_irq(adapter);

	ifcvf_free_config_irq(adapter);

	ifcvf_free_irq_vectors(pdev);

}
@@ -86,48 +160,201 @@ static int ifcvf_alloc_vectors(struct ifcvf_adapter *adapter) 
	return ret;

}



static int ifcvf_request_irq(struct ifcvf_adapter *adapter)

static int ifcvf_request_per_vq_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;

	int vector, nvectors, i, ret, irq;

	int i, vector, ret, irq;



	vf->vqs_reused_irq = -EINVAL;

	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;

		irq = pci_irq_vector(pdev, vector);

		ret = devm_request_irq(&pdev->dev, irq,

				       ifcvf_vq_intr_handler, 0,

				       vf->vring[i].msix_name,

				       &vf->vring[i]);

		if (ret) {

			IFCVF_ERR(pdev, "Failed to request irq for vq %d\n", i);

			goto err;

		}



		vf->vring[i].irq = irq;

		ret = ifcvf_set_vq_vector(vf, i, vector);

		if (ret == VIRTIO_MSI_NO_VECTOR) {

			IFCVF_ERR(pdev, "No msix vector for vq %u\n", i);

			goto err;

		}

	}



	return 0;

err:

	ifcvf_free_irq(adapter);



	nvectors = ifcvf_alloc_vectors(adapter);

	if (nvectors <= 0)

	return -EFAULT;

}



static int ifcvf_request_vqs_reused_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;

	int i, vector, ret, irq;



	snprintf(vf->config_msix_name, 256, "ifcvf[%s]-config\n",

		 pci_name(pdev));

	vector = 0;

	vf->config_irq = pci_irq_vector(pdev, vector);

	ret = devm_request_irq(&pdev->dev, vf->config_irq,

			       ifcvf_config_changed, 0,

			       vf->config_msix_name, vf);

	snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-vqs-reused-irq\n", pci_name(pdev));

	irq = pci_irq_vector(pdev, vector);

	ret = devm_request_irq(&pdev->dev, irq,

			       ifcvf_vqs_reused_intr_handler, 0,

			       vf->vring[0].msix_name, vf);

	if (ret) {

		IFCVF_ERR(pdev, "Failed to request config irq\n");

		return ret;

		IFCVF_ERR(pdev, "Failed to request reused irq for the device\n");

		goto err;

	}



	vf->vqs_reused_irq = irq;

	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;

		vf->vring[i].irq = -EINVAL;

		ret = ifcvf_set_vq_vector(vf, i, vector);

		if (ret == VIRTIO_MSI_NO_VECTOR) {

			IFCVF_ERR(pdev, "No msix vector for vq %u\n", i);

			goto err;

		}

	}



	return 0;

err:

	ifcvf_free_irq(adapter);



	return -EFAULT;

}



static int ifcvf_request_dev_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;

	int i, vector, ret, irq;



	vector = 0;

	snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-dev-irq\n", pci_name(pdev));

	irq = pci_irq_vector(pdev, vector);

	ret = devm_request_irq(&pdev->dev, irq,

				       ifcvf_intr_handler, 0,

				       vf->vring[i].msix_name,

				       &vf->vring[i]);

			       ifcvf_dev_intr_handler, 0,

			       vf->vring[0].msix_name, vf);

	if (ret) {

			IFCVF_ERR(pdev,

				  "Failed to request irq for vq %d\n", i);

			ifcvf_free_irq(adapter, i);

		IFCVF_ERR(pdev, "Failed to request irq for the device\n");

		goto err;

	}



	vf->vqs_reused_irq = irq;

	for (i = 0; i < vf->nr_vring; i++) {

		vf->vring[i].irq = -EINVAL;

		ret = ifcvf_set_vq_vector(vf, i, vector);

		if (ret == VIRTIO_MSI_NO_VECTOR) {

			IFCVF_ERR(pdev, "No msix vector for vq %u\n", i);

			goto err;

		}

	}



	vf->config_irq = irq;

	ret = ifcvf_set_config_vector(vf, vector);

	if (ret == VIRTIO_MSI_NO_VECTOR) {

		IFCVF_ERR(pdev, "No msix vector for device config\n");

		goto err;

	}



	return 0;

err:

	ifcvf_free_irq(adapter);



	return -EFAULT;



}



static int ifcvf_request_vq_irq(struct ifcvf_adapter *adapter)

{

	struct ifcvf_hw *vf = &adapter->vf;

	int ret;



	if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG)

		ret = ifcvf_request_per_vq_irq(adapter);

	else

		ret = ifcvf_request_vqs_reused_irq(adapter);



	return ret;

}



		vf->vring[i].irq = irq;

static int ifcvf_request_config_irq(struct ifcvf_adapter *adapter)

{

	struct pci_dev *pdev = adapter->pdev;

	struct ifcvf_hw *vf = &adapter->vf;

	int config_vector, ret;



	if (vf->msix_vector_status == MSIX_VECTOR_DEV_SHARED)

		return 0;



	if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG)

		/* vector 0 ~ vf->nr_vring for vqs, num vf->nr_vring vector for config interrupt */

		config_vector = vf->nr_vring;



	if (vf->msix_vector_status ==  MSIX_VECTOR_SHARED_VQ_AND_CONFIG)

		/* vector 0 for vqs and 1 for config interrupt */

		config_vector = 1;



	snprintf(vf->config_msix_name, 256, "ifcvf[%s]-config\n",

		 pci_name(pdev));

	vf->config_irq = pci_irq_vector(pdev, config_vector);

	ret = devm_request_irq(&pdev->dev, vf->config_irq,

			       ifcvf_config_changed, 0,

			       vf->config_msix_name, vf);

	if (ret) {

		IFCVF_ERR(pdev, "Failed to request config irq\n");

		goto err;

	}



	ret = ifcvf_set_config_vector(vf, config_vector);

	if (ret == VIRTIO_MSI_NO_VECTOR) {

		IFCVF_ERR(pdev, "No msix vector for device config\n");

		goto err;

	}



	return 0;

err:

	ifcvf_free_irq(adapter);



	return -EFAULT;

}



static int ifcvf_request_irq(struct ifcvf_adapter *adapter)

{

	struct ifcvf_hw *vf = &adapter->vf;

	int nvectors, ret, max_intr;



	nvectors = ifcvf_alloc_vectors(adapter);

	if (nvectors <= 0)

		return -EFAULT;



	vf->msix_vector_status = MSIX_VECTOR_PER_VQ_AND_CONFIG;

	max_intr = vf->nr_vring + 1;

	if (nvectors < max_intr)

		vf->msix_vector_status = MSIX_VECTOR_SHARED_VQ_AND_CONFIG;



	if (nvectors == 1) {

		vf->msix_vector_status = MSIX_VECTOR_DEV_SHARED;

		ret = ifcvf_request_dev_irq(adapter);



		return ret;

	}



	ret = ifcvf_request_vq_irq(adapter);

	if (ret)

		return ret;



	ret = ifcvf_request_config_irq(adapter);



	if (ret)

		return ret;



	return 0;

}
@@ -284,7 +511,7 @@ static int ifcvf_vdpa_reset(struct vdpa_device *vdpa_dev) 


	if (status_old & VIRTIO_CONFIG_S_DRIVER_OK) {

		ifcvf_stop_datapath(adapter);

		ifcvf_free_irq(adapter, vf->nr_vring);

		ifcvf_free_irq(adapter);

	}



	ifcvf_reset_vring(adapter);
@@ -431,7 +658,10 @@ static int ifcvf_vdpa_get_vq_irq(struct vdpa_device *vdpa_dev, 
{

	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);



	if (vf->vqs_reused_irq < 0)

		return vf->vring[qid].irq;

	else

		return -EINVAL;

}



static struct vdpa_notification_area ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev,