On 7/25/2024 3:44 PM, Zhou Shengqing wrote:
On 7/24/2024 2:35 PM, Zhou Shengqing wrote:
Do you mean it shoud be like this?
while ((d = pci_get_device(PCI_VENDOR_ID_INTEL, 0x09a2, d))) {
if (d->bus->number == dev->bus->number) {
pci_read_config_word(d, 0x1c0, &en1k);
if (en1k & 0x4) {
pci_info(dev, "1K I/O windows enabled per %s EN1K setting\n", pci_name(d));
dev->io_window_1k = 1;
}
}
}
00:00.0 System peripheral: Intel Corporation Device 09a2 (rev 20)
00:0f.0 PCI bridge: Intel Corporation Device 1bbf (rev 10) (prog-if 00 [Normal decode])
15:00.0 System peripheral: Intel Corporation Device 09a2 (rev 20)
15:01.0 PCI bridge: Intel Corporation Device 352a (rev 04) (prog-if 00 [Normal decode])
and if you check domain number only, they might sit on different bus, perhaps that
would make thing complex, could you make sure the VT-d is on the upstream bus of the
bridge ?
I checked it on ICX SPR EMR GNR, VT-d is always on the same bus with root port,
and VT-d device and function number is always 0.
Yes, every VT-d instance in the root complex and the root port integrated are
on the same bus. and VT-d is the first device of that bus.
The EDS doesn't say if there is exception one of the VT-d instances in an
system its EN1K wasn't set while others were set, vice vesa. so I suggest
just check the VT-d and then set the root port's io_windows_1k of the same bus.
But as Bjorn mentioned at July 12, 2024, 6:48 p.m.,
"To be safe, "d" (the [8086:09a2] device) should be on the same bus as
"dev" (with VMD, I think we get Root Ports *below* the VMD bridge,
which would be a different bus, and they presumably are not influenced
by the EN1K bit."
When VMD enabled, just check bus number identical may lead to enable
1k io windows for VMD domain root port. E.g. 0000:80:00.0 is a
VT-d(09a2). If VMD enabled, there might be a root port 10000:80:01.0 present.
this code may lead to enable 10000:80:01.0 io_window_1k = 1.
This is probably not expected.
If I modify it like this,
while ((d = pci_get_device(PCI_VENDOR_ID_INTEL, 0x09a2, d))) {
BTW, don't save letters to use single letter variable 'd', please use 'vtd_dev' or
something else to express the VT-d device.
Got it!
---if (d->bus->number == dev->bus->number) {
+++if (d->bus == dev->bus) {
What if their 'bus' are NULL, though it is almost impossible. :)
pci_read_config_word(d, 0x1c0, &en1k);
if (en1k & 0x4) {
pci_info(dev, "1K I/O windows enabled per %s EN1K setting\n", pci_name(d));
dev->io_window_1k = 1;
}
}
}
Can the situation mentioned above be avoided?
Yes, my understanding, as Bjorn pointed out root port extended from VMD
bridge not on the same bus as VT-d.
For the root port extended from VMD, should the 1k window be set
when BIOS setup EN1K knob enabled?
In my case, I think EN1K should not apply to the VMD root port.
But what I'm confused about is, how can I reasonably exclude the VMD root port
in the code?
VMD, if enabled, is EP, not RP. and its RPs are mapped into its own space, and
sit at different buses as VT-d, no need to care about them if am correct.
Thanks,
Ethan
