Re: [PATCH kvmtool 01/21] ioport: Remove ioport__setup_arch()

[Andre Przywara <andre.przywara@arm.com>]

On Wed, 10 Feb 2021 17:44:59 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:

Hi Alex,

> On 12/10/20 2:28 PM, Andre Przywara wrote:
> > Since x86 had a special need for registering tons of special I/O ports,
> > we had an ioport__setup_arch() callback, to allow each architecture
> > to do the same. As it turns out no one uses it beside x86, so we remove
> > that unnecessary abstraction.
> >
> > The generic function was registered via a device_base_init() call, so
> > we just do the same for the x86 specific function only, and can remove
> > the unneeded ioport__setup_arch().
> >
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >  arm/ioport.c         |  5 -----
> >  include/kvm/ioport.h |  1 -
> >  ioport.c             | 28 ----------------------------
> >  mips/kvm.c           |  5 -----
> >  powerpc/ioport.c     |  6 ------
> >  x86/ioport.c         | 25 ++++++++++++++++++++++++-
> >  6 files changed, 24 insertions(+), 46 deletions(-)
> >
> > diff --git a/arm/ioport.c b/arm/ioport.c
> > index 2f0feb9a..24092c9d 100644
> > --- a/arm/ioport.c
> > +++ b/arm/ioport.c
> > @@ -1,11 +1,6 @@
> >  #include "kvm/ioport.h"
> >  #include "kvm/irq.h"
> >  
> > -int ioport__setup_arch(struct kvm *kvm)
> > -{
> > -	return 0;
> > -}
> > -
> >  void ioport__map_irq(u8 *irq)
> >  {
> >  	*irq = irq__alloc_line();
> > diff --git a/include/kvm/ioport.h b/include/kvm/ioport.h
> > index 039633f7..d0213541 100644
> > --- a/include/kvm/ioport.h
> > +++ b/include/kvm/ioport.h
> > @@ -35,7 +35,6 @@ struct ioport_operations {
> >  							    enum irq_type));
> >  };
> >  
> > -int ioport__setup_arch(struct kvm *kvm);
> >  void ioport__map_irq(u8 *irq);
> >  
> >  int __must_check ioport__register(struct kvm *kvm, u16 port, struct ioport_operations *ops,
> > diff --git a/ioport.c b/ioport.c
> > index 844a832d..667e8386 100644
> > --- a/ioport.c
> > +++ b/ioport.c
> > @@ -158,21 +158,6 @@ int ioport__unregister(struct kvm *kvm, u16 port)
> >  	return 0;
> >  }
> >  
> > -static void ioport__unregister_all(void)
> > -{
> > -	struct ioport *entry;
> > -	struct rb_node *rb;
> > -	struct rb_int_node *rb_node;
> > -
> > -	rb = rb_first(&ioport_tree);
> > -	while (rb) {
> > -		rb_node = rb_int(rb);
> > -		entry = ioport_node(rb_node);
> > -		ioport_unregister(&ioport_tree, entry);
> > -		rb = rb_first(&ioport_tree);
> > -	}
> > -}  
> 
> I get the impression this is a rebasing artifact. The commit message doesn't
> mention anything about removing ioport__exit() -> ioport__unregister_all(), and as
> far as I can tell it's still needed because there are places other than
> ioport__setup_arch() from where ioport__register() is called.

I agree that the commit message is a bit thin on this fact, but the
functionality of ioport__unregister_all() is now in
x86/ioport.c:ioport__remove_arch(). I think removing ioport__init()
without removing ioport__exit() as well would look very weird, if not
hackish.

I can amend the commit message to mention this, or is there anything
else I missed?

Cheers,
Andre

> 
> > -
> >  static const char *to_direction(int direction)
> >  {
> >  	if (direction == KVM_EXIT_IO_IN)
> > @@ -220,16 +205,3 @@ out:
> >  
> >  	return !kvm->cfg.ioport_debug;
> >  }
> > -
> > -int ioport__init(struct kvm *kvm)
> > -{
> > -	return ioport__setup_arch(kvm);
> > -}
> > -dev_base_init(ioport__init);
> > -
> > -int ioport__exit(struct kvm *kvm)
> > -{
> > -	ioport__unregister_all();
> > -	return 0;
> > -}
> > -dev_base_exit(ioport__exit);
> > diff --git a/mips/kvm.c b/mips/kvm.c
> > index 26355930..e110e5d5 100644
> > --- a/mips/kvm.c
> > +++ b/mips/kvm.c
> > @@ -100,11 +100,6 @@ void kvm__irq_trigger(struct kvm *kvm, int irq)
> >  		die_perror("KVM_IRQ_LINE ioctl");
> >  }
> >  
> > -int ioport__setup_arch(struct kvm *kvm)
> > -{
> > -	return 0;
> > -}
> > -
> >  bool kvm__arch_cpu_supports_vm(void)
> >  {
> >  	return true;
> > diff --git a/powerpc/ioport.c b/powerpc/ioport.c
> > index 0c188b61..a5cff4ee 100644
> > --- a/powerpc/ioport.c
> > +++ b/powerpc/ioport.c
> > @@ -12,12 +12,6 @@
> >  
> >  #include <stdlib.h>
> >  
> > -int ioport__setup_arch(struct kvm *kvm)
> > -{
> > -	/* PPC has no legacy ioports to set up */
> > -	return 0;
> > -}
> > -
> >  void ioport__map_irq(u8 *irq)
> >  {
> >  }
> > diff --git a/x86/ioport.c b/x86/ioport.c
> > index 7ad7b8f3..8c5c7699 100644
> > --- a/x86/ioport.c
> > +++ b/x86/ioport.c
> > @@ -69,7 +69,7 @@ void ioport__map_irq(u8 *irq)
> >  {
> >  }
> >  
> > -int ioport__setup_arch(struct kvm *kvm)
> > +static int ioport__setup_arch(struct kvm *kvm)
> >  {
> >  	int r;
> >  
> > @@ -150,3 +150,26 @@ int ioport__setup_arch(struct kvm *kvm)
> >  
> >  	return 0;
> >  }
> > +dev_base_init(ioport__setup_arch);
> > +
> > +static int ioport__remove_arch(struct kvm *kvm)
> > +{
> > +	ioport__unregister(kvm, 0x510);
> > +	ioport__unregister(kvm, 0x402);
> > +	ioport__unregister(kvm, 0x03D5);
> > +	ioport__unregister(kvm, 0x03D4);
> > +	ioport__unregister(kvm, 0x0378);
> > +	ioport__unregister(kvm, 0x0278);
> > +	ioport__unregister(kvm, 0x00F0);
> > +	ioport__unregister(kvm, 0x00ED);
> > +	ioport__unregister(kvm, IOPORT_DBG);
> > +	ioport__unregister(kvm, 0x00C0);
> > +	ioport__unregister(kvm, 0x00A0);
> > +	ioport__unregister(kvm, 0x0092);
> > +	ioport__unregister(kvm, 0x0040);
> > +	ioport__unregister(kvm, 0x0020);
> > +	ioport__unregister(kvm, 0x0000);
> > +
> > +	return 0;
> > +}
> > +dev_base_exit(ioport__remove_arch);