On 07/16/18 11:45, Liu, Jing2 wrote: > Hi Laszlo, > > On 7/12/2018 3:29 PM, Laszlo Ersek wrote: >> On 07/12/18 07:43, Liu, Jing2 wrote: >>> Yep, thanks for the advice. >>> But hotplugging on pci-bridge is the actual use case >>> request so we would better solve and fix this. >> >> >> You can cold-plug a PCI Express Root Port in the Q35 root complex >> (pcie.0), reserving the MMIO resources you want, cold-plug a PCIE-PCI >> Bridge in that root port, and then hot-plug the desired endpoint into >> that PCIE-PCI Bridge. > > I'm trying this. But actual results show that, > when pcie-pci-bridge has no coldplug device, it shows all NONE for each > windows. > 01:00.0 PCI bridge: Red Hat, Inc. Device 000e (prog-if 00 [Normal decode]) > I/O behind bridge: None > Memory behind bridge: None > Prefetchable memory behind bridge: None
Can you check /proc/iomem, and dmesg? What is your exact QEMU command line? BTW, there's also <https://bugzilla.redhat.com/show_bug.cgi?id=1536147>. It might be relevant here. (I haven't personally tested SeaBIOS in the hotplug scenario at hand, but it's been my understanding that, as long as you cold-plug the PCIe-PCI bridge itself, RHBZ#1536147 shouldn't apply, and the hotplug into the bridge should just work. Personally I've only tested the same with OVMF only.) Adding Marcel and Alexander to the thread (likely belatedly; sorry about that). Thanks Laszlo > Only if I cold plug some device (e.g. e1000) under it, and then hotplug > another device might be successful. > > BTW, I open the guest kernel config: CONFIG_PCI_REALLOC_ENABLE_AUTO=y, > but it doesn't work. > I'm not sure if there are some other issues I forgot? > > Jing > > This is one of the exact examples that >> "docs/pcie_pci_bridge.txt" provides. (The other example is when the >> PCIE-PCI bridge itself is hot-plugged into the root port, for which bus >> number reservation is necessary too, at the root port level.) >> >> If you want more than that, e.g. do something similar on i440fx, that >> will take QEMU work as well, not just SeaBIOS. >> >> Laszlo >> > _______________________________________________ SeaBIOS mailing list SeaBIOS@seabios.org https://mail.coreboot.org/mailman/listinfo/seabios
