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

[Sander Eikelenboom]

Wednesday, February 5, 2014, 5:35:32 PM, you wrote:

> 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.

It's fixed with the patch, you don't need to pass that global parameter.
(i only tested it with igor's upcoming branch and the debug-patches (printk's 
only) applied though)

>> --
>> 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
>> >>
>> >>
>> 
>> 
>> 
>>