Re: [libvirt] [PATCH 4/4] Re-arrange PCI device address assignment to match QEMU's default

To try and ensure that people upgrading from old QEMU get guests with the same PCI device ordering, change the way we assign addrs to match QEMU's default order. This should make Windows less annoyed. * src/qemu/qemu_conf.c: Follow QEMU's default PCI ordering logic when assigning addresses --- src/qemu/qemu_conf.c | 124 +++++++++++++++++++++++++++++++------------------- 1 files changed, 77 insertions(+), 47 deletions(-) diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index ae345fb..5075970 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -2239,7 +2239,33 @@ int qemuDomainPCIAddressSetNextAddr(qemuDomainPCIAddressSetPtr addrs, return -1; } - +/* + * This assigns static PCI slots to all configured devices. + * The ordering here is chosen to match the ordering used + * with old QEMU < 0.12, so that if a user updates a QEMU + * host from old QEMU to QEMU >= 0.12, their guests should + * get PCI addresses in the same order as before. + * + * NB, if they previously hotplugged devices then all bets + * are off. Hotplug for old QEMU was unfixably broken wrt + * to stable PCI addressing. + * + * Order is: + * + * - Host bridge (slot 0) + * - PIIX3 ISA bridge, IDE controller, something else unknown, USB controller (slot 1) + * - Video (slot 2) + * + * Incrementally assign slots from 3 onwards: + * + * - Net + * - Sound + * - SCSI controllers + * - VirtIO block + * - VirtIO balloon + * - Host device passthrough + * - Watchdog + */

+ + /* Disks (VirtIO only for nwo */