Re: [PATCH 06/10] qapi: make Xen event commands unconditionally available

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, May 08, 2025 at 10:48:22AM -0700, David Woodhouse wrote:
> On Thu, 2025-05-08 at 17:01 +0200, Philippe Mathieu-Daudé wrote:
> > Cc'ing Zhao
> > 
> > On 8/5/25 15:58, Daniel P. Berrangé wrote:
> 
> Hm, what mailer does that? Does it mean August 5th or May 8th? Even in
> the original definition of RFC821 they knew not to use dates in those
> forms :)
> 
> > > This removes the TARGET_I386 condition from the Xen event channel
> > > commands, moving them to the recently introduced misc-i386.json
> > > QAPI file, given they are inherantly i386 specific commands.
> 
> 'inherently'
> 
> > 
> > > ---
> > > -##
> > > -# @EvtchnPortType:
> > > -#
> > > -# An enumeration of Xen event channel port types.
> > > -#
> > > -# @closed: The port is unused.
> > > -#
> > > -# @unbound: The port is allocated and ready to be bound.
> > > -#
> > > -# @interdomain: The port is connected as an interdomain interrupt.
> > > -#
> > > -# @pirq: The port is bound to a physical IRQ (PIRQ).
> > > -#
> > > -# @virq: The port is bound to a virtual IRQ (VIRQ).
> > > -#
> > > -# @ipi: The post is an inter-processor interrupt (IPI).
> > > -#
> > > -# Since: 8.0
> > > -##
> > > -{ 'enum': 'EvtchnPortType',
> > > -  'data': ['closed', 'unbound', 'interdomain', 'pirq', 'virq', 'ipi'],
> > > -  'if': 'TARGET_I386' }
> > 
> > Interesting, this ought to be "all {TARGET_I386, CONFIG_KVM}".
> 
> Isn't it CONFIG_XEN_EMU? But ISTR it wasn't possible to depend on those
> target-specific options in generic code? I forget the precise details.
> 
> So we ended up just ensuring the stubs were provided in the right
> cases.
> 
> This patch moves those stubs from hw/i386/kvm/xen-stubs.c which was
> built if !CONFIG_XEN_EMU, and moves them elsewhere if !CONFIG_KVM? So
> at first glance I think it might fail for KVM && !XEN_EMU builds... ?

The files in the top level 'stubs/' directory get built into
libqemuutil.a, and thus those stubs are available to every
system binary, in every configuration scenario.

If the real impl of these methods is present in any binary, the stubs
file impl should get discarded by the linker automatically, avoiding
a duplicate symbols problem.

With regards,
Daniel
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