Re: [Qemu-devel] [PATCH] pc_piix: enable legacy hotplug for Xen

[Stefano Stabellini]

On Tue, 4 Feb 2014, Sander Eikelenboom wrote:
> Tuesday, February 4, 2014, 10:55:18 PM, you wrote:
> 
> > Il 04/02/2014 22:32, Michael S. Tsirkin ha scritto:
> >> xenfv has no fwcfg and so does not load acpi from QEMU.
> >> as such new acpi features don't work.
> >>
> >> Reported-by: Sander Eikelenboom <address@hidden>
> >> Signed-off-by: Michael S. Tsirkin <address@hidden>
> >> ---
> >>
> >> Sander, could you pleas econfirm this works for you?
> 
> Yes this works for me (still on top of the debug patches + pull of the branch 
> igor mentoined),
> but without -global PIIX4_PM.acpi-pci-hotplug-with-bridge-support=off:
> 
> No fw cfg. Bailing out.
> bsel: 0, bus: pci.0
> bsel: 0, bus: pci.0
> bsel: 0, bus: pci.0
> bsel: 0, bus: pci.0
> 

Sander, thanks for testing and reporting the issue in the first place.

Just to be clear: does the patch fix PCI passthrough completely or do
you still need to pass -global
PIIX4_PM.acpi-pci-hotplug-with-bridge-support=off?
Sorry but I couldn't quite understand your reply.




> --
> Sander
> 
> >> Also, Xen really should switch to fw cfg some day ...
> 
> > Yeah, especially because nowadays "-M pc" works with Xen.  It would be 
> > nice if fw_cfg could be enabled even for Xen on all machines except the 
> > legacy "-M xenfv".
> 
> > Stefano, could you give it a shot now that you'll be soon done with 4.4?
> 
> > Paolo
> 
> >>  hw/i386/pc_piix.c | 11 +++++++++++
> >>  1 file changed, 11 insertions(+)
> >>
> >> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> >> index a327d71..1acd2b2 100644
> >> --- a/hw/i386/pc_piix.c
> >> +++ b/hw/i386/pc_piix.c
> >> @@ -793,6 +793,17 @@ static QEMUMachine xenfv_machine = {
> >>      .max_cpus = HVM_MAX_VCPUS,
> >>      .default_machine_opts = "accel=xen",
> >>      .hot_add_cpu = pc_hot_add_cpu,
> >> +    .compat_props = (GlobalProperty[]) {
> >> +        /* xenfv has no fwcfg and so does not load acpi from QEMU.
> >> +         * as such new acpi features don't work.
> >> +         */
> >> +        {
> >> +            .driver   = "PIIX4_PM",
> >> +            .property = "acpi-pci-hotplug-with-bridge-support",
> >> +            .value    = "off",
> >> +        },
> >> +        { /* end of list */ }
> >> +    },
> >>  };
> >>  #endif
> >>
> >>
> 
> 
> 
>