Thread (49 messages) 49 messages, 6 authors, 2021-01-19

Re: [PATCH mlx5-next v1 2/5] PCI: Add SR-IOV sysfs entry to read number of MSI-X vectors

From: Leon Romanovsky <leon@kernel.org>
Date: 2021-01-19 06:21:33
Also in: linux-pci, linux-rdma

On Mon, Jan 18, 2021 at 06:03:22PM +0100, Greg KH wrote:
On Sun, Jan 10, 2021 at 05:07:24PM +0200, Leon Romanovsky wrote:
quoted
From: Leon Romanovsky <leonro@nvidia.com>

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@nvidia.com>
---
 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 05e26e5da54e..64e9b700acc9 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
 		supports the ->sriov_set_msix_vec_count() callback 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@nvidia.com>
+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 42c0df4158d1..0a6ddf3230fd 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, "%d\n", pdev->sriov->vf_total_msix);
Nit, please use sysfs_emit() for new sysfs files.
I'll do, thanks.
thanks,

greg k-h
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