On Wed, 2024-02-07 at 12:55 -0600, Bjorn Helgaas wrote: > On Tue, Feb 06, 2024 at 05:27:29PM -0700, Nirmal Patel wrote: > > ... > > Did you have a chance to look at my response on January 16th to > > your > > questions? I tried to summarize all of the potential problems and > > issues with different fixes. Please let me know if it is easier if > > I > > resend the explanation. Thanks. > > I did see your Jan 16 response, thanks. > > I had more questions after reading it, but they're more about > understanding the topology seen by the host and the guest: > Jan 16: https://lore.kernel.org/r/20240117004933.GA108810@bhelgaas > Feb 1: https://lore.kernel.org/r/20240201211620.GA650432@bhelgaas > > As I mentioned in my second Feb 1 response > (https://lore.kernel.org/r/20240201222245.GA650725@bhelgaas), the > usual plan envisioned by the PCI Firmware spec is that an OS can use > a > PCIe feature if the platform has granted the OS ownership via _OSC > and > a device advertises the feature via a Capability in config space. > > My main concern with the v2 patch > ( > https://lore.kernel.org/r/20231127211729.42668-1-nirmal.patel@xxxxxxxxxxxxxxx > ) > is that it overrides _OSC for native_pcie_hotplug, but not for any of > the other features (AER, PME, LTR, DPC, etc.) > > I think it's hard to read the specs and conclude that PCIe hotplug is > a special case, and I think we're likely to have similar issues with > other features in the future. > > But if you think this is the best solution, I'm OK with merging it. I sincerely apologize for late responses. I just found out that my evolution mail client is automatically sending linux-pci emails to junk since January 2024. At the moment Hotplug is an exception for us, but I do share your concern about other flags. We have done lot of testing and so far patch v2 is the best solution we have. Thanks nirmal > > Bjorn