Re: [libvirt] [PATCH 2/6] qemu: allow some PCI devices to be attached to PCIe slots

Part of the resolution to: https://bugzilla.redhat.com/show_bug.cgi?id=1003983 Although most devices available in qemu area defined as PCI devices, and strictly speaking should only be attached via a PCI slot, in practice qemu allows them to be attached to a PCIe slot and sometimes this makes sense. For example, The UHCI and EHCI USB controllers are usually attached directly to the PCIe "root complex" (i.e. PCIe slots) on real hardware, so that should be possible for a Q35-based qemu virtual machine as well. We still want to prefer a standard PCi slot when auto-assigning

addresses, though, and in general to disallow attaching PCI devices via PCIe slots. This patch makes that possible by adding a new QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG flag. Three things are done with this flag: 1) It is set for the "pcie-root" controller 2) qemuCollectPCIAddress() now has a set of nested switches that set this "EITHER" flag for devices that we want to allow connecting to pcie-root when specifically requested in the config. 3) qemuDomainPCIAddressFlagsCompatible() adds this new flag to the "flagsMatchMask" if the address being checked came from config rather than being newly auto-allocated by libvirt (this knowledge is conveniently already available in the "fromConfig" arg). Now any device having the EITHER flag set can be connected to pcie-root if explicitly requested, but auto-allocated addresses for those devices will still be standard PCI slots instead. This patch only loosens the restrictions on devices that have been specifically requested, but the setup is such that it should be fairly easy to add new devices. --- src/qemu/qemu_command.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++--- src/qemu/qemu_command.h | 4 ++++ 2 files changed, 51 insertions(+), 3 deletions(-)