On 03/21/2013 08:58 AM, Michael S. Tsirkin wrote: >> >> Most of them do really ugly hacks in hardware (like putting in a "back >> door" in config space) to make that possible. > > config space register that let us access > registers within BAR actually sounds pretty reasonable. > Way better than an I/O BAR. > It is really, really, nasty, not to mention slow. >>> >>> Problem is, BIOS and OS normally assume failure to allocate >>> any resources means card won't function and disable it. >>> So it does not seem to be worth it to have such a >>> device specific failover ability. >>> >> >> That is a violation of the PCIe spec; the PCIe spec specifically states >> that failure to allocate an I/O BAR should still allow the device to >> function. > > Where does it say this? In PCI Express 1.1 base, it is section 1.3.2.2, third bullet. -hpa _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
