On Mon, 23 May 2016 20:23:19 +0200 Thomas Huth <thuth@xxxxxxxxxx> wrote: > On 23.05.2016 10:28, Greg Kurz wrote: > > A strange behaviour is observed when comparing PCI hotplug in QEMU, between > > x86 and pseries. If you consider the following steps: > > - start a VM > > - add a PCI device via the QEMU monitor before the rtasd has started (for > > example starting the VM in paused state, or hotplug during FW or boot > > loader) > > - resume the VM execution > > > > The x86 kernel detects the PCI device, but the pseries one does not. > > > > This happens because the rtasd kernel worker is currently started under > > device_initcall, while PCI probing happens earlier under subsys_initcall. > > > > As a consequence, if we have a pending RTAS event at boot time, a message > > is printed and the event is dropped. > > > > This patch moves all the initialization of rtasd to arch_initcall, which is > > run before subsys_call: this way, logging_enabled is true when the RTAS > > event pops up and it is not lost anymore. > > > > The proc fs bits stay at device_initcall because they cannot be run before > > fs_initcall. > > > > Signed-off-by: Greg Kurz <gkurz@xxxxxxxxxxxxxxxxxx> > > --- > > arch/powerpc/kernel/rtasd.c | 19 ++++++++++++++----- > > 1 file changed, 14 insertions(+), 5 deletions(-) > > By the way, same is true for device UNplugging: When unplugging devices > in QEMU while the firmware is still running, they are never properly > removed from the guest. I've checked it, and your patch fixes this > problem as well! Great :-) > > Tested-by: Thomas Huth <thuth@xxxxxxxxxx> > Indeed, all pending RTAS events were lost... now rtasd will log them, up to 64 events, but I did not test that far :) Thanks for testing ! Cheers. -- Greg -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
