[SRU,Xenial,2/2] PCI: hv: Use device serial number as PCI domain

Submitted by Joseph Salisbury on Feb. 28, 2017, 4:55 p.m.

Details

Message ID 82925c20030b318dd6972ff9df95c054acc77e2d.1488299293.git.joseph.salisbury@canonical.com
State New
Headers show

Commit Message

Joseph Salisbury Feb. 28, 2017, 4:55 p.m.
From: Haiyang Zhang <haiyangz@microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1667527

Use the device serial number as the PCI domain.  The serial numbers start
with 1 and are unique within a VM.  So names, such as VF NIC names, that
include domain number as part of the name, can be shorter than that based
on part of bus UUID previously.  The new names will also stay same for VMs
created with copied VHD and same number of devices.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
(cherry picked from commit 4a9b0933bdfcd85da840284bf5a0eb17b654b9c2)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
---
 drivers/pci/host/pci-hyperv.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 2bbfdfa..88cf169 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1312,6 +1312,18 @@  static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
 	get_pcichild(hpdev, hv_pcidev_ref_initial);
 	get_pcichild(hpdev, hv_pcidev_ref_childlist);
 	spin_lock_irqsave(&hbus->device_list_lock, flags);
+
+	/*
+	 * When a device is being added to the bus, we set the PCI domain
+	 * number to be the device serial number, which is non-zero and
+	 * unique on the same VM.  The serial numbers start with 1, and
+	 * increase by 1 for each device.  So device names including this
+	 * can have shorter names than based on the bus instance UUID.
+	 * Only the first device serial number is used for domain, so the
+	 * domain number will not change after the first device is added.
+	 */
+	if (list_empty(&hbus->children))
+		hbus->sysdata.domain = desc->ser;
 	list_add_tail(&hpdev->list_entry, &hbus->children);
 	spin_unlock_irqrestore(&hbus->device_list_lock, flags);
 	return hpdev;