On 28.07.22 17:26, Jan Beulich wrote:
Hello Jan
On 28.07.2022 16:16, Oleksandr wrote:
On 27.07.22 13:32, Jan Beulich wrote:
On 19.07.2022 19:42, Oleksandr Tyshchenko wrote:
From: Oleksandr Andrushchenko <[email protected]>
Assign SBDF to the PCI devices being passed through with bus 0.
The resulting topology is where PCIe devices reside on the bus 0 of the
root complex itself (embedded endpoints).
This implementation is limited to 32 devices which are allowed on
a single PCI bus.
Please note, that at the moment only function 0 of a multifunction
device can be passed through.
I've not been able to spot where this restriction is being enforced -
can you please point me at the respective code?
Nor have I found the respective code.
Could you please suggest a place where to put such enforcement (I guess,
this should be present in the toolstack)?
Such check should be in the tool stack primarily to give a sensible
error message to the user. Yet the hypervisor needs to check itself
nevertheless. You know the code you're adding much better than I do,
so I guess I'm a little puzzled by you asking me to suggest a place.
(And for the tool stack I guess asking tool stack folks would get
you better mileage.)
Thanks for the clarification.
I am still getting used to the changes which that patch series makes (I
didn't write that code).
Asking for suggestion I didn't mean to point an exact place in the code,
but rather a subsystem/software layer,
sorry if I was unclear.
@@ -124,6 +191,7 @@ void vpci_deassign_device(struct pci_dev *pdev)
if ( !has_vpci(pdev->domain) )
return;
+ vpci_remove_virtual_device(pdev);
vpci_remove_device(pdev);
}
And other call sites of vpci_remove_device() do not have a need of
cleaning up guest_sbdf / vpci_dev_assigned_map?
I am not 100% sure, but it looks like they don't need. On the other
hand, even if they don't need that, doing the cleaning won't be an issue
at all,
there is a check before cleaning (which will be extended as I proposed
above), so ...
IOW I wonder if it
wouldn't be better to have vpci_remove_device() do this as well
(retaining - see my comment on the earlier patch) the simple aliasing
of vpci_deassign_device() to vpci_remove_device()).
... maybe yes. Shall I do that change?
Well - yes please, afaic.
ok, will do
Jan
--
Regards,
Oleksandr Tyshchenko
