[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Bug 1900918] Re: PXB devices
From: |
bwidawsk |
Subject: |
[Bug 1900918] Re: PXB devices |
Date: |
Wed, 21 Oct 2020 23:39:44 -0000 |
*** This bug is a duplicate of bug 1900919 ***
https://bugs.launchpad.net/bugs/1900919
I accidentally double submitted this, and this one has the wrong description.
Please close and use
#1900919 instead.
** This bug has been marked a duplicate of bug 1900919
PXB selected as root bus incorrectly
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1900918
Title:
PXB devices
Status in QEMU:
New
Bug description:
release: 4c41341af76cfc85b5a6c0f87de4838672ab9f89
qdev_device_add() will search for the "closest" bus possible, and bail out
early if that bus is a root bus. pxb devices are considered root buses and so
if you either
1. Add a PCI device on the QEMU command line *after* a pxb device, or
2. Add an integrated PCI device (like a watchdog)
#1: -device pxb-pcie,id=cxl.0,bus=pcie.0,bus_nr=52 -device
ahci,id=sata0,addr=0x8
#2: -watchdog i6300esb -device pxb-pcie,id=cxl.0,bus=pcie.0,bus_nr=52
The PXB will get selected as the bus (instead of the real root bus)
and this will cause an assertion failure with the message like "qemu-
system-x86_64: -device ahci,id=sata0,addr=0x8: PCI: Only PCI/PCIe
bridges can be plugged into pxb-pcie"
I think this is relatively solvable in the code base by determining if
a bus is an expander, and skipping it if so. However, I wonder if it
makes more sense to just allow expanders to have endpoint devices.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1900918/+subscriptions