From: Leon Romanovsky <leonro@xxxxxxxxxx>
Some SR-IOV capable devices provide an ability to configure specific
number of MSI-X vectors on their VF prior driver is probed on that VF.
In order to make management easy, provide new read-only sysfs file that
returns a total number of possible to configure MSI-X vectors.
cat /sys/bus/pci/devices/.../sriov_vf_total_msix
= 0 - feature is not supported
> 0 - total number of MSI-X vectors to consume by the VFs
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-pci | 14 +++++++++++
drivers/pci/iov.c | 31 +++++++++++++++++++++++++
drivers/pci/pci.h | 3 +++
include/linux/pci.h | 2 ++
4 files changed, 50 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 34a8c6bcde70..530c249cc3da 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -395,3 +395,17 @@ Description:
The file is writable if the PF is bound to a driver that
set sriov_vf_total_msix > 0 and there is no driver bound
to the VF.
+
+What: /sys/bus/pci/devices/.../sriov_vf_total_msix
+Date: January 2021
+Contact: Leon Romanovsky <leonro@xxxxxxxxxx>
+Description:
+ This file is associated with the SR-IOV PFs.
+ It returns a total number of possible to configure MSI-X
+ vectors on the enabled VFs.
+
+ The values returned are:
+ * > 0 - this will be total number possible to consume by VFs,
+ * = 0 - feature is not supported
+
+ If no SR-IOV VFs are enabled, this value will return 0.
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 5bc496f8ffa3..f9dc31947dbc 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -394,12 +394,22 @@ static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
return count;
}
+static ssize_t sriov_vf_total_msix_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return sprintf(buf, "%u\n", pdev->sriov->vf_total_msix);
+}
+
static DEVICE_ATTR_RO(sriov_totalvfs);
static DEVICE_ATTR_RW(sriov_numvfs);
static DEVICE_ATTR_RO(sriov_offset);
static DEVICE_ATTR_RO(sriov_stride);
static DEVICE_ATTR_RO(sriov_vf_device);
static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
+static DEVICE_ATTR_RO(sriov_vf_total_msix);
static struct attribute *sriov_dev_attrs[] = {
&dev_attr_sriov_totalvfs.attr,
@@ -408,6 +418,7 @@ static struct attribute *sriov_dev_attrs[] = {
&dev_attr_sriov_stride.attr,
&dev_attr_sriov_vf_device.attr,
&dev_attr_sriov_drivers_autoprobe.attr,
+ &dev_attr_sriov_vf_total_msix.attr,
NULL,
};
@@ -654,6 +665,7 @@ static void sriov_disable(struct pci_dev *dev)
sysfs_remove_link(&dev->dev.kobj, "dep_link");
iov->num_VFs = 0;
+ iov->vf_total_msix = 0;
pci_iov_set_numvfs(dev, 0);
}
@@ -1112,6 +1124,25 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev)
}
EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
+/**
+ * pci_sriov_set_vf_total_msix - set total number of MSI-X vectors for the VFs
+ * @dev: the PCI PF device
+ * @count: the total number of MSI-X vector to consume by the VFs
+ *
+ * Sets the number of MSI-X vectors that is possible to consume by the VFs.
+ * This interface is complimentary part of the pci_set_msix_vec_count()
+ * that will be used to configure the required number on the VF.
+ */
+void pci_sriov_set_vf_total_msix(struct pci_dev *dev, u32 count)
+{
+ if (!dev->is_physfn || !dev->driver ||
+ !dev->driver->sriov_set_msix_vec_count)
+ return;
+
+ dev->sriov->vf_total_msix = count;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_set_vf_total_msix);
+
/**
* pci_sriov_configure_simple - helper to configure SR-IOV
* @dev: the PCI device
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index dbbfa9e73ea8..604e1f9172c2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -327,6 +327,9 @@ struct pci_sriov {
u16 subsystem_device; /* VF subsystem device */
resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */
bool drivers_autoprobe; /* Auto probing of VFs by driver */
+ u32 vf_total_msix; /* Total number of MSI-X vectors the VFs
+ * can consume
+ */
};
/**
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6be96d468eda..c950513558b8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2075,6 +2075,7 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev);
int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn);
resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno);
void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool probe);
+void pci_sriov_set_vf_total_msix(struct pci_dev *dev, u32 count);
/* Arch may override these (weak) */
int pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs);
@@ -2115,6 +2116,7 @@ static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
static inline resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
{ return 0; }
static inline void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool probe) { }
+static inline void pci_sriov_set_vf_total_msix(struct pci_dev *dev, u32 count) {}
#endif
#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
--
2.29.2
