Michael S. Tsirkin
2022-Jan-25 19:42 UTC
[PATCH V2 4/4] vDPA/ifcvf: implement shared IRQ feature
On Tue, Jan 25, 2022 at 05:17:44PM +0800, Zhu Lingshan wrote:> On some platforms/devices, there may not be enough MSI vector > slots allocated for 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. > > This commit adds some fields in struct ifcvf_hw and re-placed > the existed fields to be aligned with the cacheline. > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > --- > drivers/vdpa/ifcvf/ifcvf_base.c | 47 +++++-- > drivers/vdpa/ifcvf/ifcvf_base.h | 23 ++- > drivers/vdpa/ifcvf/ifcvf_main.c | 240 +++++++++++++++++++++++++++----- > 3 files changed, 253 insertions(+), 57 deletions(-) > > diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c > index 397692ae671c..18dcb63ab1e3 100644 > --- a/drivers/vdpa/ifcvf/ifcvf_base.c > +++ b/drivers/vdpa/ifcvf/ifcvf_base.c > @@ -15,6 +15,36 @@ struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw) > return container_of(hw, struct ifcvf_adapter, vf); > } > > +int ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector) > +{ > + struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg; > + struct ifcvf_adapter *ifcvf = vf_to_adapter(hw); > + > + ifc_iowrite16(qid, &cfg->queue_select); > + ifc_iowrite16(vector, &cfg->queue_msix_vector); > + if (ifc_ioread16(&cfg->queue_msix_vector) == VIRTIO_MSI_NO_VECTOR) { > + IFCVF_ERR(ifcvf->pdev, "No msix vector for queue %u\n", qid); > + return -EINVAL; > + } > + > + return 0; > +} > + > +int ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector) > +{ > + struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg; > + struct ifcvf_adapter *ifcvf = vf_to_adapter(hw); > + > + cfg = hw->common_cfg; > + ifc_iowrite16(vector, &cfg->msix_config); > + if (ifc_ioread16(&cfg->msix_config) == VIRTIO_MSI_NO_VECTOR) { > + IFCVF_ERR(ifcvf->pdev, "No msix vector for device config\n"); > + return -EINVAL; > + } > + > + return 0; > +} > + > static void __iomem *get_cap_addr(struct ifcvf_hw *hw, > struct virtio_pci_cap *cap) > { > @@ -140,6 +170,8 @@ 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_shared_irq = -EINVAL; > +This stuffing of errno values into u32 is not a good idea.> return 0; > } > > @@ -321,12 +353,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) > > ifcvf = vf_to_adapter(hw); > cfg = hw->common_cfg; > - ifc_iowrite16(IFCVF_MSI_CONFIG_OFF, &cfg->msix_config); > - > - if (ifc_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) > @@ -340,15 +366,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) > ifc_iowrite64_twopart(hw->vring[i].used, &cfg->queue_used_lo, > &cfg->queue_used_hi); > ifc_iowrite16(hw->vring[i].size, &cfg->queue_size); > - ifc_iowrite16(i + IFCVF_MSI_QUEUE_OFF, &cfg->queue_msix_vector); > - > - if (ifc_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); > ifc_iowrite16(1, &cfg->queue_enable); > } > diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h > index 949b4fb9d554..d2a2a526f0fc 100644 > --- a/drivers/vdpa/ifcvf/ifcvf_base.h > +++ b/drivers/vdpa/ifcvf/ifcvf_base.h > @@ -27,8 +27,6 @@ > > #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 > @@ -42,6 +40,13 @@ > #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 > + > static inline u8 ifc_ioread8(u8 __iomem *addr) > { > return ioread8(addr); > @@ -97,25 +102,27 @@ struct ifcvf_hw { > u8 __iomem *isr; > /* Live migration */ > u8 __iomem *lm_cfg; > - u16 nr_vring; > /* Notification bar number */ > u8 notify_bar; > + u8 msix_vector_status; > + /* virtio-net or virtio-blk device config size */ > + u32 config_size; > /* Notificaiton bar address */ > void __iomem *notify_base; > phys_addr_t notify_base_pa; > u32 notify_off_multiplier; > + u32 dev_type; > u64 req_features; > u64 hw_features; > - u32 dev_type; > struct virtio_pci_common_cfg __iomem *common_cfg; > void __iomem *dev_cfg; > struct vring_info vring[IFCVF_MAX_QUEUES]; > void __iomem * const *base; > char config_msix_name[256]; > struct vdpa_callback config_cb; > - unsigned int config_irq; > - /* virtio-net or virtio-blk device config size */ > - u32 config_size; > + u32 config_irq; > + u32 vqs_shared_irq; > + u16 nr_vring; > }; > > struct ifcvf_adapter { > @@ -160,4 +167,6 @@ 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); > +int ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector); > +int ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector); > #endif /* _IFCVF_H_ */ > diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c > index 7e2af2d2aaf5..c7070ff01776 100644 > --- a/drivers/vdpa/ifcvf/ifcvf_main.c > +++ b/drivers/vdpa/ifcvf/ifcvf_main.c > @@ -17,6 +17,7 @@ > #define DRIVER_AUTHOR "Intel Corporation" > #define IFCVF_DRIVER_NAME "ifcvf" > > +/* handles config interrupt */ > static irqreturn_t ifcvf_config_changed(int irq, void *arg) > { > struct ifcvf_hw *vf = arg; > @@ -27,6 +28,7 @@ static irqreturn_t ifcvf_config_changed(int irq, void *arg) > return IRQ_HANDLED; > } > > +/* handles vqs interrupt */ > static irqreturn_t ifcvf_intr_handler(int irq, void *arg) > { > struct vring_info *vring = arg; > @@ -37,24 +39,77 @@ static irqreturn_t ifcvf_intr_handler(int irq, void *arg) > return IRQ_HANDLED; > } > > +/* handls vqs shared interrupt */ > +static irqreturn_t ifcvf_vq_shared_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) > + vf->vring->cb.callback(vring->cb.private); > + } > + > + return IRQ_HANDLED; > +} > + > +/* handles a shared interrupt for vqs and config */ > +static irqreturn_t ifcvf_dev_shared_intr_handler(int irq, void *arg) > +{ > + struct ifcvf_hw *vf = arg; > + u8 isr; > + > + isr = ifc_ioread8(vf->isr); > + if (isr & VIRTIO_PCI_ISR_CONFIG) > + ifcvf_config_changed(irq, arg); > + > + return ifcvf_vq_shared_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_vq_irq(struct ifcvf_adapter *adapter, int queues) > { > struct pci_dev *pdev = adapter->pdev; > struct ifcvf_hw *vf = &adapter->vf; > int i; > > + if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG) > + for (i = 0; i < queues; i++) { > + devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]); > + vf->vring[i].irq = -EINVAL; > + } > + else { > + devm_free_irq(&pdev->dev, vf->vqs_shared_irq, vf); > + } vf->vqs_shared_irq = -EINVAL;If you use {} in the else branch, use it on the then branch, too.> +} > > - for (i = 0; i < queues; i++) { > - devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]); > - vf->vring[i].irq = -EINVAL; > +static void ifcvf_free_config_irq(struct ifcvf_adapter *adapter) > +{ > + struct pci_dev *pdev = adapter->pdev; > + struct ifcvf_hw *vf = &adapter->vf; > + > + /* 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, int queues) > +{ > + struct pci_dev *pdev = adapter->pdev; > > - devm_free_irq(&pdev->dev, vf->config_irq, vf); > + ifcvf_free_vq_irq(adapter, queues); > + ifcvf_free_config_irq(adapter); > ifcvf_free_irq_vectors(pdev); > } > > @@ -81,58 +136,170 @@ 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, i, ret, irq; > - u16 nvectors, max_intr; > + int i, vector, ret, irq; > > - nvectors = ifcvf_alloc_vectors(adapter); > - if (!(nvectors > 0)) > - return nvectors; > + 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_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); > + ifcvf_free_vq_irq(adapter, i); > + } else { > + vf->vring[i].irq = irq; > + ifcvf_set_vq_vector(vf, i, vector); > + } > + } > > - max_intr = vf->nr_vring + 1; > + vf->vqs_shared_irq = -EINVAL; > + > + return 0; > +} > + > +static int ifcvf_request_shared_vq_irq(struct ifcvf_adapter *adapter) > +{ > + struct pci_dev *pdev = adapter->pdev; > + struct ifcvf_hw *vf = &adapter->vf; > + int i, vector, ret, irq; > + > + vector = 0; > + irq = pci_irq_vector(pdev, vector); > + ret = devm_request_irq(&pdev->dev, irq, > + ifcvf_vq_shared_intr_handler, 0, > + "ifcvf_vq_shared_irq", > + vf); > + if (ret) { > + IFCVF_ERR(pdev, "Failed to request shared irq for vf\n"); > + > + return ret; > + } > + > + vf->vqs_shared_irq = irq; > + for (i = 0; i < vf->nr_vring; i++) { > + vf->vring[i].irq = -EINVAL; > + ifcvf_set_vq_vector(vf, i, vector); > + } > + > + return 0; > + > +} > + > +static int ifcvf_request_dev_shared_irq(struct ifcvf_adapter *adapter) > +{ > + struct pci_dev *pdev = adapter->pdev; > + struct ifcvf_hw *vf = &adapter->vf; > + int i, vector, ret, irq; > + > + vector = 0; > + irq = pci_irq_vector(pdev, vector); > + ret = devm_request_irq(&pdev->dev, irq, > + ifcvf_dev_shared_intr_handler, 0, > + "ifcvf_dev_shared_irq", > + vf); > + if (ret) { > + IFCVF_ERR(pdev, "Failed to request shared irq for vf\n"); > > - 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; > } > > + vf->vqs_shared_irq = irq; > + for (i = 0; i < vf->nr_vring; i++) { > + vf->vring[i].irq = -EINVAL; > + ifcvf_set_vq_vector(vf, i, vector); > + } > + > + vf->config_irq = irq; > + ifcvf_set_config_vector(vf, vector); > + > + return 0; > + > +} > + > +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_shared_vq_irq(adapter); > + > + return ret; > +} > + > +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)); > - vector = 0; > - vf->config_irq = pci_irq_vector(pdev, vector); > + 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"); > + ifcvf_free_vq_irq(adapter, vf->nr_vring); > return ret; > } > + ifcvf_set_config_vector(vf, config_vector); > > - 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; > - 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]); > - if (ret) { > - IFCVF_ERR(pdev, > - "Failed to request irq for vq %d\n", i); > - ifcvf_free_irq(adapter, i); > + return 0; > +} > > - return ret; > - } > +static int ifcvf_request_irq(struct ifcvf_adapter *adapter)This function was not moved, was it? Try --minimal or --histogram maybe. Or just --anchored=ifcvf_request_irq> +{ > + struct ifcvf_hw *vf = &adapter->vf; > + u16 nvectors, max_intr; > + int ret; > > - vf->vring[i].irq = irq; > + nvectors = ifcvf_alloc_vectors(adapter); > + if (!(nvectors > 0)) > + return nvectors; > +> + 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_shared_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; > } > > @@ -436,7 +603,10 @@ static int ifcvf_vdpa_get_vq_irq(struct vdpa_device *vdpa_dev, > { > struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev); > > - return vf->vring[qid].irq; > + if (vf->vqs_shared_irq < 0) > + return vf->vring[qid].irq; > + else > + return -EINVAL; > } > > static struct vdpa_notification_area ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev, > -- > 2.27.0