[PATCH mlx5-next v3 0/5] Dynamically assign MSI-X vectors count

[PATCH mlx5-next v3 0/5] Dynamically assign MSI-X vectors count

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

Changelog
v3:
 * Renamed pci_set_msix_vec_count to be pci_vf_set_msix_vec_count.
 * Added VF msix_cap check to hide sysfs entry if device doesn't support msix.
 * Changed "-" to be ":" in the mlx5 patch to silence CI warnings about missing
   kdoc description.
 * Split differently error print in mlx5 driver to avoid checkpatch warning.
v2: https://lore.kernel.org/linux-pci/20210114103140.866141-1-leon@kernel.org
 * Patch 1:
  * Renamed vf_msix_vec sysfs knob to be sriov_vf_msix_count
  * Added PF and VF device locks during set MSI-X call to protect from parallel
    driver bind/unbind operations.
  * Removed extra checks when reading sriov_vf_msix, because users will
    be able to distinguish between supported/not supported by looking on
    sriov_vf_total_msix count.
  * Changed all occurrences of "numb" to be "count"
  * Changed returned error from EOPNOTSUPP to be EBUSY if user tries to set
    MSI-X count after driver already bound to the VF.
  * Added extra comment in pci_set_msix_vec_count() to emphasize that driver
    should not be bound.
 * Patch 2:
  * Changed vf_total_msix from int to be u32 and updated function signatures
    accordingly.
  * Improved patch title
v1: https://lore.kernel.org/linux-pci/20210110150727.1965295-1-leon@kernel.org
 * Improved wording and commit messages of first PCI patch
 * Added extra PCI patch to provide total number of MSI-X vectors
 * Prohibited read of vf_msix_vec sysfs file if driver doesn't support write
 * Removed extra function definition in pci.h
v0: https://lore.kernel.org/linux-pci/20210103082440.34994-1-leon@kernel.org

--------------------------------------------------------------------

Hi,

The number of MSI-X vectors is PCI property visible through lspci, that
field is read-only and configured by the device.

The static assignment of an amount of MSI-X vectors doesn't allow utilize
the newly created VF because it is not known to the device the future load
and configuration where that VF will be used.

The VFs are created on the hypervisor and forwarded to the VMs that have
different properties (for example number of CPUs).

To overcome the inefficiency in the spread of such MSI-X vectors, we
allow the kernel to instruct the device with the needed number of such
vectors, before VF is initialized and bounded to the driver.

Before this series:
[root@server ~]# lspci -vs 0000:08:00.2
08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function]
....
        Capabilities: [9c] MSI-X: Enable- Count=12 Masked-

Configuration script:
1. Start fresh
echo 0 > /sys/bus/pci/devices/0000\:08\:00.0/sriov_numvfs
modprobe -q -r mlx5_ib mlx5_core
2. Ensure that driver doesn't run and it is safe to change MSI-X
echo 0 > /sys/bus/pci/devices/0000\:08\:00.0/sriov_drivers_autoprobe
3. Load driver for the PF
modprobe mlx5_core
4. Configure one of the VFs with new number
echo 2 > /sys/bus/pci/devices/0000\:08\:00.0/sriov_numvfs
echo 21 > /sys/bus/pci/devices/0000\:08\:00.2/sriov_vf_msix_count

After this series:
[root@server ~]# lspci -vs 0000:08:00.2
08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function]
....
        Capabilities: [9c] MSI-X: Enable- Count=21 Masked-

Thanks

Leon Romanovsky (5):
  PCI: Add sysfs callback to allow MSI-X table size change of SR-IOV VFs
  PCI: Add SR-IOV sysfs entry to read total number of dynamic MSI-X
    vectors
  net/mlx5: Add dynamic MSI-X capabilities bits
  net/mlx5: Dynamically assign MSI-X vectors count
  net/mlx5: Allow to the users to configure number of MSI-X vectors

 Documentation/ABI/testing/sysfs-bus-pci       | 34 +++++++
 .../net/ethernet/mellanox/mlx5/core/main.c    |  5 +
 .../ethernet/mellanox/mlx5/core/mlx5_core.h   |  6 ++
 .../net/ethernet/mellanox/mlx5/core/pci_irq.c | 72 ++++++++++++++
 .../net/ethernet/mellanox/mlx5/core/sriov.c   | 51 +++++++++-
 drivers/pci/iov.c                             | 94 +++++++++++++++++++
 drivers/pci/msi.c                             | 47 ++++++++++
 drivers/pci/pci-sysfs.c                       |  1 +
 drivers/pci/pci.h                             |  5 +
 include/linux/mlx5/mlx5_ifc.h                 | 11 ++-
 include/linux/pci.h                           |  5 +
 11 files changed, 328 insertions(+), 3 deletions(-)

--
2.29.2

[PATCH mlx5-next v3 1/5] PCI: Add sysfs callback to allow MSI-X table size change of SR-IOV VFs

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

Extend PCI sysfs interface with a new callback that allows configure
the number of MSI-X vectors for specific SR-IO VF. This is needed
to optimize the performance of newly bound devices by allocating
the number of vectors based on the administrator knowledge of targeted VM.

This function is applicable for SR-IOV VF because such devices allocate
their MSI-X table before they will run on the VMs and HW can't guess the
right number of vectors, so the HW allocates them statically and equally.

The newly added /sys/bus/pci/devices/.../sriov_vf_msix_count file will be seen
for the VFs and it is writable as long as a driver is not bounded to the VF.

The values accepted are:
 * > 0 - this will be number reported by the VF's MSI-X capability
 * < 0 - not valid
 * = 0 - will reset to the device default value

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 Documentation/ABI/testing/sysfs-bus-pci | 20 ++++++
 drivers/pci/iov.c                       | 82 +++++++++++++++++++++++++
 drivers/pci/msi.c                       | 47 ++++++++++++++
 drivers/pci/pci-sysfs.c                 |  1 +
 drivers/pci/pci.h                       |  2 +
 include/linux/pci.h                     |  3 +
 6 files changed, 155 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 25c9c39770c6..34a8c6bcde70 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -375,3 +375,23 @@ Description:
 		The value comes from the PCI kernel device state and can be one
 		of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold".
 		The file is read only.
+
+What:		/sys/bus/pci/devices/.../sriov_vf_msix_count
+Date:		December 2020
+Contact:	Leon Romanovsky <leonro@nvidia.com>
+Description:
+		This file is associated with the SR-IOV VFs.
+		It allows configuration of the number of MSI-X vectors for
+		the VF. This is needed to optimize performance of newly bound
+		devices by allocating the number of vectors based on the
+		administrator knowledge of targeted VM.
+
+		The values accepted are:
+		 * > 0 - this will be number reported by the VF's MSI-X
+			 capability
+		 * < 0 - not valid
+		 * = 0 - will reset to the device default value
+
+		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.
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 4afd4ee4f7f0..b8d7a3b26f87 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -31,6 +31,7 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
 	return (dev->devfn + dev->sriov->offset +
 		dev->sriov->stride * vf_id) & 0xff;
 }
+EXPORT_SYMBOL(pci_iov_virtfn_devfn);

 /*
  * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
@@ -426,6 +427,68 @@ const struct attribute_group sriov_dev_attr_group = {
 	.is_visible = sriov_attrs_are_visible,
 };

+#ifdef CONFIG_PCI_MSI
+static ssize_t sriov_vf_msix_count_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int count = pci_msix_vec_count(pdev);
+
+	if (count < 0)
+		return count;
+
+	return sprintf(buf, "%d\n", count);
+}
+
+static ssize_t sriov_vf_msix_count_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct pci_dev *vf_dev = to_pci_dev(dev);
+	int val, ret;
+
+	ret = kstrtoint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = pci_vf_set_msix_vec_count(vf_dev, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(sriov_vf_msix_count);
+#endif
+
+static struct attribute *sriov_vf_dev_attrs[] = {
+#ifdef CONFIG_PCI_MSI
+	&dev_attr_sriov_vf_msix_count.attr,
+#endif
+	NULL,
+};
+
+static umode_t sriov_vf_attrs_are_visible(struct kobject *kobj,
+					  struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *vf_dev;
+
+	if (dev_is_pf(dev))
+		return 0;
+
+	vf_dev = to_pci_dev(dev);
+	if (!vf_dev->msix_cap)
+		return 0;
+
+	return a->mode;
+}
+
+const struct attribute_group sriov_vf_dev_attr_group = {
+	.attrs = sriov_vf_dev_attrs,
+	.is_visible = sriov_vf_attrs_are_visible,
+};
+
 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
 {
 	return 0;
@@ -1054,6 +1117,25 @@ 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_vf_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/msi.c b/drivers/pci/msi.c
index 3162f88fe940..05a9dfc3397b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -991,6 +991,53 @@ int pci_msix_vec_count(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_msix_vec_count);

+/**
+ * pci_vf_set_msix_vec_count - change the reported number of MSI-X vectors
+ * This function is applicable for SR-IOV VF because such devices allocate
+ * their MSI-X table before they will run on the VMs and HW can't guess the
+ * right number of vectors, so the HW allocates them statically and equally.
+ * @dev: VF device that is going to be changed
+ * @count amount of MSI-X vectors
+ **/
+int pci_vf_set_msix_vec_count(struct pci_dev *dev, int count)
+{
+	struct pci_dev *pdev = pci_physfn(dev);
+	int ret;
+
+	if (!dev->msix_cap || !pdev->msix_cap || count < 0)
+		/*
+		 * We don't support negative numbers for now,
+		 * but maybe in the future it will make sense.
+		 */
+		return -EINVAL;
+
+	device_lock(&pdev->dev);
+	if (!pdev->driver || !pdev->driver->sriov_set_msix_vec_count) {
+		ret = -EOPNOTSUPP;
+		goto err_pdev;
+	}
+
+	device_lock(&dev->dev);
+	if (dev->driver) {
+		/*
+		 * Driver already probed this VF and configured itself
+		 * based on previously configured (or default) MSI-X vector
+		 * count. It is too late to change this field for this
+		 * specific VF.
+		 */
+		ret = -EBUSY;
+		goto err_dev;
+	}
+
+	ret = pdev->driver->sriov_set_msix_vec_count(dev, count);
+
+err_dev:
+	device_unlock(&dev->dev);
+err_pdev:
+	device_unlock(&pdev->dev);
+	return ret;
+}
+
 static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
 			     int nvec, struct irq_affinity *affd, int flags)
 {
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index fb072f4b3176..0af2222643c2 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1557,6 +1557,7 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
 	&pci_dev_hp_attr_group,
 #ifdef CONFIG_PCI_IOV
 	&sriov_dev_attr_group,
+	&sriov_vf_dev_attr_group,
 #endif
 	&pci_bridge_attr_group,
 	&pcie_dev_attr_group,
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5c59365092fa..a275018beb2f 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -183,6 +183,7 @@ extern unsigned int pci_pm_d3hot_delay;

 #ifdef CONFIG_PCI_MSI
 void pci_no_msi(void);
+int pci_vf_set_msix_vec_count(struct pci_dev *dev, int count);
 #else
 static inline void pci_no_msi(void) { }
 #endif
@@ -502,6 +503,7 @@ resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno);
 void pci_restore_iov_state(struct pci_dev *dev);
 int pci_iov_bus_range(struct pci_bus *bus);
 extern const struct attribute_group sriov_dev_attr_group;
+extern const struct attribute_group sriov_vf_dev_attr_group;
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b32126d26997..6be96d468eda 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -856,6 +856,8 @@ struct module;
  *		e.g. drivers/net/e100.c.
  * @sriov_configure: Optional driver callback to allow configuration of
  *		number of VFs to enable via sysfs "sriov_numvfs" file.
+ * @sriov_set_msix_vec_count: Driver callback to change number of MSI-X vectors
+ *              exposed by the sysfs "vf_msix_vec" entry.
  * @err_handler: See Documentation/PCI/pci-error-recovery.rst
  * @groups:	Sysfs attribute groups.
  * @driver:	Driver model structure.
@@ -871,6 +873,7 @@ struct pci_driver {
 	int  (*resume)(struct pci_dev *dev);	/* Device woken up */
 	void (*shutdown)(struct pci_dev *dev);
 	int  (*sriov_configure)(struct pci_dev *dev, int num_vfs); /* On PF */
+	int  (*sriov_set_msix_vec_count)(struct pci_dev *vf, int msix_vec_count); /* On PF */
 	const struct pci_error_handlers *err_handler;
 	const struct attribute_group **groups;
 	struct device_driver	driver;
--
2.29.2

[PATCH mlx5-next v3 2/5] PCI: Add SR-IOV sysfs entry to read total number of dynamic MSI-X vectors

[Leon Romanovsky]

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                       | 12 ++++++++++++
 drivers/pci/pci.h                       |  3 +++
 include/linux/pci.h                     |  2 ++
 4 files changed, 31 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@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 b8d7a3b26f87..6660632b7a14 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,
 };

@@ -659,6 +670,7 @@ 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);
 }

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index a275018beb2f..444e03ce9c97 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

[PATCH mlx5-next v3 3/5] net/mlx5: Add dynamic MSI-X capabilities bits

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

These new fields declare the number of MSI-X vectors that is
possible to allocate on the VF through PF configuration.

Value must be in range defined by min_dynamic_vf_msix_table_size
and max_dynamic_vf_msix_table_size.

The driver should continue to query its MSI-X table through PCI
configuration header.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 include/linux/mlx5/mlx5_ifc.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
index 8c5d5fe58051..7ac614bc592a 100644
--- a/include/linux/mlx5/mlx5_ifc.h
+++ b/include/linux/mlx5/mlx5_ifc.h
@@ -1656,7 +1656,16 @@ struct mlx5_ifc_cmd_hca_cap_bits {
 	u8	   reserved_at_6e0[0x10];
 	u8	   sf_base_id[0x10];
 
-	u8	   reserved_at_700[0x80];
+	u8	   reserved_at_700[0x8];
+	u8	   num_total_dynamic_vf_msix[0x18];
+	u8	   reserved_at_720[0x14];
+	u8	   dynamic_msix_table_size[0xc];
+	u8	   reserved_at_740[0xc];
+	u8	   min_dynamic_vf_msix_table_size[0x4];
+	u8	   reserved_at_750[0x4];
+	u8	   max_dynamic_vf_msix_table_size[0xc];
+
+	u8	   reserved_at_760[0x20];
 	u8	   vhca_tunnel_commands[0x40];
 	u8	   reserved_at_7c0[0x40];
 };
-- 
2.29.2

[PATCH mlx5-next v3 4/5] net/mlx5: Dynamically assign MSI-X vectors count

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

The number of MSI-X vectors is PCI property visible through lspci, that
field is read-only and configured by the device. The static assignment
of an amount of MSI-X vectors doesn't allow utilize the newly created
VF because it is not known to the device the future load and configuration
where that VF will be used.

To overcome the inefficiency in the spread of such MSI-X vectors, we
allow the kernel to instruct the device with the needed number of such
vectors.

Such change immediately increases the amount of MSI-X vectors for the
system with @ VFs from 12 vectors per-VF, to be 32 vectors per-VF.

Before this patch:
[root@server ~]# lspci -vs 0000:08:00.2
08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function]
....
	Capabilities: [9c] MSI-X: Enable- Count=12 Masked-

After this patch:
[root@server ~]# lspci -vs 0000:08:00.2
08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function]
....
	Capabilities: [9c] MSI-X: Enable- Count=32 Masked-

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/main.c    |  4 ++
 .../ethernet/mellanox/mlx5/core/mlx5_core.h   |  5 ++
 .../net/ethernet/mellanox/mlx5/core/pci_irq.c | 72 +++++++++++++++++++
 .../net/ethernet/mellanox/mlx5/core/sriov.c   | 13 +++-
 4 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
index c08315b51fd3..8269cfbfc69d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -567,6 +567,10 @@ static int handle_hca_cap(struct mlx5_core_dev *dev, void *set_ctx)
 	if (MLX5_CAP_GEN_MAX(dev, mkey_by_name))
 		MLX5_SET(cmd_hca_cap, set_hca_cap, mkey_by_name, 1);
 
+	if (MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix))
+		MLX5_SET(cmd_hca_cap, set_hca_cap, num_total_dynamic_vf_msix,
+			 MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix));
+
 	return set_caps(dev, set_ctx, MLX5_SET_HCA_CAP_OP_MOD_GENERAL_DEVICE);
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index 0a0302ce7144..5babb4434a87 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -172,6 +172,11 @@ int mlx5_irq_attach_nb(struct mlx5_irq_table *irq_table, int vecidx,
 		       struct notifier_block *nb);
 int mlx5_irq_detach_nb(struct mlx5_irq_table *irq_table, int vecidx,
 		       struct notifier_block *nb);
+
+int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int devfn,
+			    int msix_vec_count);
+int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs);
+
 struct cpumask *
 mlx5_irq_get_affinity_mask(struct mlx5_irq_table *irq_table, int vecidx);
 struct cpu_rmap *mlx5_irq_get_rmap(struct mlx5_irq_table *table);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 6fd974920394..2a35888fcff0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -55,6 +55,78 @@ static struct mlx5_irq *mlx5_irq_get(struct mlx5_core_dev *dev, int vecidx)
 	return &irq_table->irq[vecidx];
 }
 
+/**
+ * mlx5_get_default_msix_vec_count() - Get defaults of number of MSI-X vectors
+ * to be set
+ * @dev: PF to work on
+ * @num_vfs: Number of VFs was asked when SR-IOV was enabled
+ **/
+int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs)
+{
+	int num_vf_msix, min_msix, max_msix;
+
+	num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix);
+	if (!num_vf_msix)
+		return 0;
+
+	min_msix = MLX5_CAP_GEN(dev, min_dynamic_vf_msix_table_size);
+	max_msix = MLX5_CAP_GEN(dev, max_dynamic_vf_msix_table_size);
+
+	/* Limit maximum number of MSI-X to leave some of them free in the
+	 * pool and ready to be assigned by the users without need to resize
+	 * other Vfs.
+	 */
+	return max(min(num_vf_msix / num_vfs, max_msix / 2), min_msix);
+}
+
+/**
+ * mlx5_set_msix_vec_count() - Set dynamically allocated MSI-X to the VF
+ * @dev: PF to work on
+ * @function_id: Internal PCI VF function id
+ * @msix_vec_count: Number of MSI-X to set
+ **/
+int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int function_id,
+			    int msix_vec_count)
+{
+	int sz = MLX5_ST_SZ_BYTES(set_hca_cap_in);
+	int num_vf_msix, min_msix, max_msix;
+	void *hca_cap, *cap;
+	int ret;
+
+	num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix);
+	if (!num_vf_msix)
+		return 0;
+
+	if (!MLX5_CAP_GEN(dev, vport_group_manager) || !mlx5_core_is_pf(dev))
+		return -EOPNOTSUPP;
+
+	min_msix = MLX5_CAP_GEN(dev, min_dynamic_vf_msix_table_size);
+	max_msix = MLX5_CAP_GEN(dev, max_dynamic_vf_msix_table_size);
+
+	if (msix_vec_count < min_msix)
+		return -EINVAL;
+
+	if (msix_vec_count > max_msix)
+		return -EOVERFLOW;
+
+	hca_cap = kzalloc(sz, GFP_KERNEL);
+	if (!hca_cap)
+		return -ENOMEM;
+
+	cap = MLX5_ADDR_OF(set_hca_cap_in, hca_cap, capability);
+	MLX5_SET(cmd_hca_cap, cap, dynamic_msix_table_size, msix_vec_count);
+
+	MLX5_SET(set_hca_cap_in, hca_cap, opcode, MLX5_CMD_OP_SET_HCA_CAP);
+	MLX5_SET(set_hca_cap_in, hca_cap, other_function, 1);
+	MLX5_SET(set_hca_cap_in, hca_cap, function_id, function_id);
+
+	MLX5_SET(set_hca_cap_in, hca_cap, op_mod,
+		 MLX5_SET_HCA_CAP_OP_MOD_GENERAL_DEVICE << 1);
+	ret = mlx5_cmd_exec_in(dev, set_hca_cap, hca_cap);
+	kfree(hca_cap);
+	return ret;
+}
+
 int mlx5_irq_attach_nb(struct mlx5_irq_table *irq_table, int vecidx,
 		       struct notifier_block *nb)
 {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
index 3094d20297a9..f0ec86a1c8a6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
@@ -71,8 +71,7 @@ static int sriov_restore_guids(struct mlx5_core_dev *dev, int vf)
 static int mlx5_device_enable_sriov(struct mlx5_core_dev *dev, int num_vfs)
 {
 	struct mlx5_core_sriov *sriov = &dev->priv.sriov;
-	int err;
-	int vf;
+	int err, vf, num_msix_count;
 
 	if (!MLX5_ESWITCH_MANAGER(dev))
 		goto enable_vfs_hca;
@@ -85,12 +84,22 @@ static int mlx5_device_enable_sriov(struct mlx5_core_dev *dev, int num_vfs)
 	}
 
 enable_vfs_hca:
+	num_msix_count = mlx5_get_default_msix_vec_count(dev, num_vfs);
 	for (vf = 0; vf < num_vfs; vf++) {
 		err = mlx5_core_enable_hca(dev, vf + 1);
 		if (err) {
 			mlx5_core_warn(dev, "failed to enable VF %d (%d)\n", vf, err);
 			continue;
 		}
+
+		err = mlx5_set_msix_vec_count(dev, vf + 1, num_msix_count);
+		if (err) {
+			mlx5_core_warn(dev,
+				       "failed to set MSI-X vector counts VF %d, err %d\n",
+				       vf, err);
+			continue;
+		}
+
 		sriov->vfs_ctx[vf].enabled = 1;
 		if (MLX5_CAP_GEN(dev, port_type) == MLX5_CAP_PORT_TYPE_IB) {
 			err = sriov_restore_guids(dev, vf);
-- 
2.29.2

[PATCH mlx5-next v3 5/5] net/mlx5: Allow to the users to configure number of MSI-X vectors

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

Implement ability to configure MSI-X for the SR-IOV VFs.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/main.c    |  1 +
 .../ethernet/mellanox/mlx5/core/mlx5_core.h   |  1 +
 .../net/ethernet/mellanox/mlx5/core/sriov.c   | 38 +++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
index 8269cfbfc69d..334b3b5077c5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -1647,6 +1647,7 @@ static struct pci_driver mlx5_core_driver = {
 	.shutdown	= shutdown,
 	.err_handler	= &mlx5_err_handler,
 	.sriov_configure   = mlx5_core_sriov_configure,
+	.sriov_set_msix_vec_count = mlx5_core_sriov_set_msix_vec_count,
 };
 
 static void mlx5_core_verify_params(void)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index 5babb4434a87..8a2523d2d43a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -138,6 +138,7 @@ void mlx5_sriov_cleanup(struct mlx5_core_dev *dev);
 int mlx5_sriov_attach(struct mlx5_core_dev *dev);
 void mlx5_sriov_detach(struct mlx5_core_dev *dev);
 int mlx5_core_sriov_configure(struct pci_dev *dev, int num_vfs);
+int mlx5_core_sriov_set_msix_vec_count(struct pci_dev *vf, int msix_vec_count);
 int mlx5_core_enable_hca(struct mlx5_core_dev *dev, u16 func_id);
 int mlx5_core_disable_hca(struct mlx5_core_dev *dev, u16 func_id);
 int mlx5_create_scheduling_element_cmd(struct mlx5_core_dev *dev, u8 hierarchy,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
index f0ec86a1c8a6..febb7a5ec72d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c
@@ -144,6 +144,7 @@ mlx5_device_disable_sriov(struct mlx5_core_dev *dev, int num_vfs, bool clear_vf)
 static int mlx5_sriov_enable(struct pci_dev *pdev, int num_vfs)
 {
 	struct mlx5_core_dev *dev  = pci_get_drvdata(pdev);
+	u32 num_vf_msix;
 	int err;
 
 	err = mlx5_device_enable_sriov(dev, num_vfs);
@@ -152,6 +153,8 @@ static int mlx5_sriov_enable(struct pci_dev *pdev, int num_vfs)
 		return err;
 	}
 
+	num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix);
+	pci_sriov_set_vf_total_msix(pdev, num_vf_msix);
 	err = pci_enable_sriov(pdev, num_vfs);
 	if (err) {
 		mlx5_core_warn(dev, "pci_enable_sriov failed : %d\n", err);
@@ -187,6 +190,41 @@ int mlx5_core_sriov_configure(struct pci_dev *pdev, int num_vfs)
 	return err ? err : num_vfs;
 }
 
+int mlx5_core_sriov_set_msix_vec_count(struct pci_dev *vf, int msix_vec_count)
+{
+	struct pci_dev *pf = pci_physfn(vf);
+	struct mlx5_core_sriov *sriov;
+	struct mlx5_core_dev *dev;
+	int num_vf_msix, id;
+
+	dev = pci_get_drvdata(pf);
+	num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix);
+	if (!num_vf_msix)
+		return -EOPNOTSUPP;
+
+	if (!msix_vec_count)
+		msix_vec_count =
+			mlx5_get_default_msix_vec_count(dev, pci_num_vf(pf));
+
+	sriov = &dev->priv.sriov;
+
+	/* Reversed translation of PCI VF function number to the internal
+	 * function_id, which exists in the name of virtfn symlink.
+	 */
+	for (id = 0; id < pci_num_vf(pf); id++) {
+		if (!sriov->vfs_ctx[id].enabled)
+			continue;
+
+		if (vf->devfn == pci_iov_virtfn_devfn(pf, id))
+			break;
+	}
+
+	if (id == pci_num_vf(pf) || !sriov->vfs_ctx[id].enabled)
+		return -EINVAL;
+
+	return mlx5_set_msix_vec_count(dev, id + 1, msix_vec_count);
+}
+
 int mlx5_sriov_attach(struct mlx5_core_dev *dev)
 {
 	if (!mlx5_core_is_pf(dev) || !pci_num_vf(dev->pdev))
-- 
2.29.2