Michael S. Tsirkin
2022-Feb-14 14:25 UTC
[PATCH V4 4/4] vDPA/ifcvf: implement shared IRQ feature
On Mon, Feb 14, 2022 at 03:19:25PM +0800, Jason Wang wrote:> > ? 2022/2/3 ??3:27, Zhu Lingshan ??: > > 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 | 243 +++++++++++++++++++++++++++----- > > 3 files changed, 256 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; > > + } > > > Let's leave this check for the caller, E.g can caller try to assign > NO_VECTOR during uni-nit?Hmm I'm not sure I agree. Caller will have to write queue select again, and that's an extra IO, which is a waste. And having function checking itself just seems better contained.> > > + > > + 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; > > + } > > > Similar question as above. > > > > + > > + 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; > > + > > 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..9cfe088c82e9 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 > > > I think there's no much value to differ 2 from 3 consider config interrupt > should be rare.Yes but if we do not have a dedicated vector then we need an extra device IO (in fact, a read) on each interrupt.> > > + > > 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; > > > Any reason for moving nv_vring, config_size, and other stuffs? > > > > /* 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; > > + int config_irq; > > + int 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 44c89ab0b6da..ca414399f040 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 */ > > > This seems unrelated to the shared IRQ logic and it looks useless since it's > easily to deduce it from the function name below. > > > > 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 */ > > > So did this. > > > > static irqreturn_t ifcvf_intr_handler(int irq, void *arg) > > { > > struct vring_info *vring = arg; > > @@ -37,24 +39,78 @@ 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)shared is not a good name given IRQ_SHARED is not set. maybe "common"? "reused"?> > +{ > > + struct ifcvf_hw *vf = arg; > > + u8 isr; > > + > > + isr = ifc_ioread8(vf->isr); > > > We need to exactly what vp_interrupt do here. Checking against vf->isr first > and return IRQ_NONE if it is not set.no, vf->isr is not set for VQ interrupts. If need to actually poke at the VQ to know.> Always return IRQ_HANDLED will break the device who shares an irq with > IFCVF.It's a MSI, not INT#. So interrupt is not shared as such - it's only sharing vector between config and vq.> > > + 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; > > + } > > +} > > - 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); > > } > > @@ -86,58 +142,172 @@ 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; > > - u16 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; > > + /* reuse msix_name[256] space of vring0 to store shared vqs interrupt name */ > > > I think we can remove this comment since the code is straightforward. > > > > + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-vqs-shared-irq\n", pci_name(pdev)); > > + irq = pci_irq_vector(pdev, vector); > > + ret = devm_request_irq(&pdev->dev, irq, > > + ifcvf_vq_shared_intr_handler, 0, > > + vf->vring[0].msix_name, 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; > > + /* reuse msix_name[256] space of vring0 to store shared device interrupt name */ > > + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-dev-shared-irq\n", pci_name(pdev)); > > + irq = pci_irq_vector(pdev, vector); > > + ret = devm_request_irq(&pdev->dev, irq, > > + ifcvf_dev_shared_intr_handler, 0, > > + vf->vring[0].msix_name, 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; > > } > > - 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); > > + ifcvf_set_config_vector(vf, config_vector); > > - return ret; > > - } > > + return 0; > > +} > > + > > +static int ifcvf_request_irq(struct ifcvf_adapter *adapter) > > +{ > > > As replied above, I think having two modes should be sufficient and the code > could be greatly simplified. > > Thanks >Well it is claimed there are platforms where we are short on vectors. 3 versus 2 seems a 50% saving. You disagree?> > + struct ifcvf_hw *vf = &adapter->vf; > > + int nvectors, ret, max_intr; > > - 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; > > } > > @@ -441,7 +611,10 @@ 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,
On Mon, Feb 14, 2022 at 10:25 PM Michael S. Tsirkin <mst at redhat.com> wrote:> > On Mon, Feb 14, 2022 at 03:19:25PM +0800, Jason Wang wrote: > > > > ? 2022/2/3 ??3:27, Zhu Lingshan ??: > > > 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 | 243 +++++++++++++++++++++++++++----- > > > 3 files changed, 256 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; > > > + } > > > > > > Let's leave this check for the caller, E.g can caller try to assign > > NO_VECTOR during uni-nit? > > > Hmm I'm not sure I agree. Caller will have to write queue select > again, and that's an extra IO, which is a waste. > And having function checking itself just seems better contained.It's as simple as just return what we read here like virtio_pci did: u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev, u16 index, u16 vector) { struct virtio_pci_common_cfg __iomem *cfg = mdev->common; vp_iowrite16(index, &cfg->queue_select); vp_iowrite16(vector, &cfg->queue_msix_vector); /* Flush the write out to device */ return vp_ioread16(&cfg->queue_msix_vector); } EXPORT_SYMBOL_GPL(vp_modern_queue_vector); Then the caller can decide to check it with NO_VECTOR if needed. Current code will break the callers that want to set NO_VECTOR.> > > > > > + > > > + 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; > > > + } > > > > > > Similar question as above. > > > > > > > + > > > + 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; > > > + > > > 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..9cfe088c82e9 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 > > > > > > I think there's no much value to differ 2 from 3 consider config interrupt > > should be rare. > > > Yes but if we do not have a dedicated vector then we need an > extra device IO (in fact, a read) on each interrupt.Ok, right.> > > > > > + > > > 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; > > > > > > Any reason for moving nv_vring, config_size, and other stuffs? > > > > > > > /* 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; > > > + int config_irq; > > > + int 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 44c89ab0b6da..ca414399f040 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 */ > > > > > > This seems unrelated to the shared IRQ logic and it looks useless since it's > > easily to deduce it from the function name below. > > > > > > > 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 */ > > > > > > So did this. > > > > > > > static irqreturn_t ifcvf_intr_handler(int irq, void *arg) > > > { > > > struct vring_info *vring = arg; > > > @@ -37,24 +39,78 @@ 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) > > shared is not a good name given IRQ_SHARED is not set. > maybe "common"? "reused"? > > > > +{ > > > + struct ifcvf_hw *vf = arg; > > > + u8 isr; > > > + > > > + isr = ifc_ioread8(vf->isr); > > > > > > We need to exactly what vp_interrupt do here. Checking against vf->isr first > > and return IRQ_NONE if it is not set. > > no, vf->isr is not set for VQ interrupts.I actually wonder what's the actual behaviour of IFCVF.> If need to actually poke > at the VQ to know. > > > Always return IRQ_HANDLED will break the device who shares an irq with > > IFCVF. > > > It's a MSI, not INT#. So interrupt is not shared as such - it's only > sharing vector between config and vq.Right, I thought it was a shared one as virito_pci did.> > > > > > > + 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; > > > + } > > > +} > > > - 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); > > > } > > > @@ -86,58 +142,172 @@ 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; > > > - u16 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; > > > + /* reuse msix_name[256] space of vring0 to store shared vqs interrupt name */ > > > > > > I think we can remove this comment since the code is straightforward. > > > > > > > + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-vqs-shared-irq\n", pci_name(pdev)); > > > + irq = pci_irq_vector(pdev, vector); > > > + ret = devm_request_irq(&pdev->dev, irq, > > > + ifcvf_vq_shared_intr_handler, 0, > > > + vf->vring[0].msix_name, 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; > > > + /* reuse msix_name[256] space of vring0 to store shared device interrupt name */ > > > + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-dev-shared-irq\n", pci_name(pdev)); > > > + irq = pci_irq_vector(pdev, vector); > > > + ret = devm_request_irq(&pdev->dev, irq, > > > + ifcvf_dev_shared_intr_handler, 0, > > > + vf->vring[0].msix_name, 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; > > > } > > > - 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); > > > + ifcvf_set_config_vector(vf, config_vector); > > > - return ret; > > > - } > > > + return 0; > > > +} > > > + > > > +static int ifcvf_request_irq(struct ifcvf_adapter *adapter) > > > +{ > > > > > > As replied above, I think having two modes should be sufficient and the code > > could be greatly simplified. > > > > Thanks > > > > Well it is claimed there are platforms where we are short > on vectors. 3 versus 2 seems a 50% saving. You disagree?I think we can 2 vectors (a dedicated for config). Thanks> > > > + struct ifcvf_hw *vf = &adapter->vf; > > > + int nvectors, ret, max_intr; > > > - 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; > > > } > > > @@ -441,7 +611,10 @@ 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, >