On 9/10/2020 12:30 AM, Tal Shnaiderman wrote:
Subject: Re: [PATCH] bus/pci: support segment value as address domain on
Windows
On Tue, Aug 25, 2020 at 02:43:16PM +0300, Tal Shnaiderman wrote:
Set the domain value for rte_pci_addr probing on Windows to the value
of the PCI segment returned by SPDRP_BUSNUMBER.
Signed-off-by: Tal Shnaiderman <tal...@nvidia.com>
---
drivers/bus/pci/windows/pci.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/pci/windows/pci.c
b/drivers/bus/pci/windows/pci.c index 489aa7902a..a40acec609 100644
--- a/drivers/bus/pci/windows/pci.c
+++ b/drivers/bus/pci/windows/pci.c
@@ -195,8 +195,8 @@ get_device_pci_address(HDEVINFO dev_info,
return -1;
}
- addr->domain = 0;
- addr->bus = bus_num;
+ addr->domain = bus_num >> 8;
+ addr->bus = bus_num & 0xff;
addr->devid = dev_and_func >> 16;
addr->function = dev_and_func & 0xffff;
return 0;
--
Is this needed to avoid collision of devices with the same B:D:F?
Right, it can happen in virtualization setups when several virtual functions
can have the same BDF, e.g.:
PS > Get-NetAdapterHardwareInfo
Name Segment Bus Device Function Slot NumaNode
PcieLinkSpeed
---- ------- --- ------ -------- ---- --------
-------------
Ethernet 0 0 10 0
Unknown
Ethernet 4 58601 0 2 0 0
Unknown
Ethernet 5 52956 0 2 0 0
Unknown
DPDK currently can detect either Ethernet 4 or ethernet 5 if only BDF is
checked.
Unix uses the Domain value, the equivalent value for Windows is Segment.
Thanks for the explanation, Tal.
I had always been curious how Windows stores the PCIe segment (domain)
number.
On VMs hosted on Hyper-V, the VF segment numbers are always in the high
16-bit values.
Is this documented somewhere, or did you find this by experimentation?
ranjit m.
