Re: [PATCH] ifcvf/vDPA: ifcvf drives standard virtio pci devices

"Zhu, Lingshan" <lingshan.zhu@xxxxxxxxx> · Tue, 14 May 2024 09:22:48 +0800

On 5/13/2024 9:38 PM, Michael S. Tsirkin wrote:
On Tue, May 14, 2024 at 05:27:07AM +0800, Zhu Lingshan wrote:
Most of ifcvf code work for standard virtio pci,
except for bar4. This commit makes bar4 only effective
for Intel products, thereby turning ifcvf into
a standard virtio pci driver.

Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
  drivers/vdpa/Kconfig            |  2 +-
  drivers/vdpa/ifcvf/ifcvf_base.c | 17 ++++++++++++-----
  drivers/vdpa/ifcvf/ifcvf_main.c |  5 ++++-
  3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
index 656c1cb541de..dbf09f35bcef 100644
--- a/drivers/vdpa/Kconfig
+++ b/drivers/vdpa/Kconfig
@@ -44,7 +44,7 @@ config VDPA_USER
  	  in a userspace program.
  
  config IFCVF
-	tristate "Intel IFC VF vDPA driver"
+	tristate "Intel IFC VF and standard virtio-pci vDPA driver"
  	depends on PCI_MSI
  	help
  	  This kernel module can drive Intel IFC VF NIC to offload
diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c
index 472daa588a9d..47bc9b11c678 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.c
+++ b/drivers/vdpa/ifcvf/ifcvf_base.c
@@ -178,7 +178,8 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct pci_dev *pdev)
  		hw->vring[i].irq = -EINVAL;
  	}
  
-	hw->lm_cfg = hw->base[IFCVF_LM_BAR];
+	if (hw->pdev->subsystem_vendor == PCI_VENDOR_ID_INTEL)
+		hw->lm_cfg = hw->base[IFCVF_LM_BAR];
  
  	IFCVF_DBG(pdev,
  		  "PCI capability mapping: common cfg: %p, notify base: %p\n, isr cfg: %p, device cfg: %p, multiplier: %u\n",
@@ -330,18 +331,24 @@ u16 ifcvf_get_vq_state(struct ifcvf_hw *hw, u16 qid)
  	struct ifcvf_lm_cfg  __iomem *lm_cfg = hw->lm_cfg;
  	u16 last_avail_idx;
  
-	last_avail_idx = vp_ioread16(&lm_cfg->vq_state_region + qid * 2);
+	if (lm_cfg) {
+		last_avail_idx = vp_ioread16(&lm_cfg->vq_state_region + qid * 2);
+		return last_avail_idx;
+	}
  
-	return last_avail_idx;
+	return -EOPNOTSUPP;
  }
  
  int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num)
  {
  	struct ifcvf_lm_cfg  __iomem *lm_cfg = hw->lm_cfg;
  
-	vp_iowrite16(num, &lm_cfg->vq_state_region + qid * 2);
+	if (lm_cfg) {
+		vp_iowrite16(num, &lm_cfg->vq_state_region + qid * 2);
+		return 0;
+	}
  
-	return 0;
+	return -EOPNOTSUPP;
  }
  
  void ifcvf_set_vq_num(struct ifcvf_hw *hw, u16 qid, u32 num)
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 80d0a0460885..e89fd4d96ff1 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -1,6 +1,7 @@
  // SPDX-License-Identifier: GPL-2.0-only
  /*
   * Intel IFC VF NIC driver for virtio dataplane offloading
+ * This driver also drives standard virtio-pci hardwares
   *
   * Copyright (C) 2020 Intel Corporation.
   *
@@ -880,7 +881,9 @@ static struct pci_device_id ifcvf_pci_ids[] = {
  			 VIRTIO_TRANS_ID_BLOCK,
  			 PCI_VENDOR_ID_INTEL,
  			 VIRTIO_ID_BLOCK) },
-
+	/* standard virtio pci devices */
+	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET,
+		     PCI_ANY_ID) },
  	{ 0 },
  };
  MODULE_DEVICE_TABLE(pci, ifcvf_pci_ids);
Will make it conflict with the normal virtio driver, won't it?

What are you trying to achieve here?
The confliction exists before, in my setup, virtio-pci driver always 
probe virtio-pci devices
before ifcvf.

Since ifcvf drives is all standard virtio-pci except for bar4, so this 
patch intends to maximize
the use of the ifcvf driver and allow developers without Intel hardware 
to also develop this driver.

Thanks
Zhu Lingshan



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