[PATCH 1/2 V2] PCI: introduce device assignment interface and refactory related code

From: Ethan Zhao
Date: Fri Jul 11 2014 - 01:53:35 EST


This patch introduces two new device assignment functions

pci_sriov_assign_device(),
pci_sriov_deassign_device()

along with the existed one

pci_vfs_assigned()

They construct the VFs assignment management interface, used to assign/
deassign device to VM and query the VFs reference counter. instead of
direct manipulation of device flag.

This patch refashioned the related code and make them atomic.

v2: reorder the patchset and make it bisectable and atomic, steps clear
between interface defination and implemenation according to the
suggestion from alex.williamson@xxxxxxxxxx

Signed-off-by: Ethan Zhao <ethan.zhao@xxxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 17 ++---------------
drivers/pci/iov.c | 20 ++++++++++++++++++++
drivers/xen/xen-pciback/pci_stub.c | 4 ++--
include/linux/pci.h | 4 ++++
virt/kvm/assigned-dev.c | 2 +-
virt/kvm/iommu.c | 4 ++--
6 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 02c11a7..781040e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -693,22 +693,9 @@ complete_reset:
static bool i40e_vfs_are_assigned(struct i40e_pf *pf)
{
struct pci_dev *pdev = pf->pdev;
- struct pci_dev *vfdev;
-
- /* loop through all the VFs to see if we own any that are assigned */
- vfdev = pci_get_device(PCI_VENDOR_ID_INTEL, I40E_DEV_ID_VF , NULL);
- while (vfdev) {
- /* if we don't own it we don't care */
- if (vfdev->is_virtfn && pci_physfn(vfdev) == pdev) {
- /* if it is assigned we cannot release it */
- if (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED)
- return true;
- }

- vfdev = pci_get_device(PCI_VENDOR_ID_INTEL,
- I40E_DEV_ID_VF,
- vfdev);
- }
+ if (pci_vfs_assigned(pdev))
+ return true;

return false;
}
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index de7a747..c082523 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -644,6 +644,26 @@ int pci_vfs_assigned(struct pci_dev *dev)
EXPORT_SYMBOL_GPL(pci_vfs_assigned);

/**
+ * pci_sriov_assign_device - assign device to VM
+ * @pdev: the device to be assigned.
+ */
+void pci_sriov_assign_device(struct pci_dev *pdev)
+{
+ pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_assign_device);
+
+/**
+ * pci_sriov_deassign_device - deasign device from VM
+ * @pdev: the device to be deassigned.
+ */
+void pci_sriov_deassign_device(struct pci_dev *pdev)
+{
+ pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_deassign_device);
+
+/**
* pci_sriov_set_totalvfs -- reduce the TotalVFs available
* @dev: the PCI PF device
* @numvfs: number that should be used for TotalVFs supported
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 62fcd48..1d7b747 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -133,7 +133,7 @@ static void pcistub_device_release(struct kref *kref)
xen_pcibk_config_free_dyn_fields(dev);
xen_pcibk_config_free_dev(dev);

- dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+ pci_sriov_deassign_device(dev);
pci_dev_put(dev);

kfree(psdev);
@@ -404,7 +404,7 @@ static int pcistub_init_device(struct pci_dev *dev)
dev_dbg(&dev->dev, "reset device\n");
xen_pcibk_reset_device(dev);

- dev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+ pci_sriov_assign_device(dev);
return 0;

config_release:
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aab57b4..ddfcceb 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1603,6 +1603,8 @@ int pci_num_vf(struct pci_dev *dev);
int pci_vfs_assigned(struct pci_dev *dev);
int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
int pci_sriov_get_totalvfs(struct pci_dev *dev);
+void pci_sriov_assign_device(struct pci_dev *dev);
+void pci_sriov_deassign_device(struct pci_dev *dev);
#else
static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
{ return -ENODEV; }
@@ -1614,6 +1616,8 @@ static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
{ return 0; }
static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
{ return 0; }
+static inline void pci_sriov_assign_device(struct pci_dev *dev) { }
+static inline void pci_sriov_deassign_device(struct pci_dev *dev) { }
#endif

#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index bf06577..80b477f 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -302,7 +302,7 @@ static void kvm_free_assigned_device(struct kvm *kvm,
else
pci_restore_state(assigned_dev->dev);

- assigned_dev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+ pci_sriov_deassign_device(assigned_dev->dev);

pci_release_regions(assigned_dev->dev);
pci_disable_device(assigned_dev->dev);
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 0df7d4b..6d3f5ef 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -194,7 +194,7 @@ int kvm_assign_device(struct kvm *kvm,
goto out_unmap;
}

- pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+ pci_sriov_assign_device(pdev);

dev_info(&pdev->dev, "kvm assign device\n");

@@ -220,7 +220,7 @@ int kvm_deassign_device(struct kvm *kvm,

iommu_detach_device(domain, &pdev->dev);

- pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+ pci_sriov_deassign_device(pdev);

dev_info(&pdev->dev, "kvm deassign device\n");

--
1.7.1

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