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

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

On Thu, 11 Feb 2021 17:32:01 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:

Hi,

> On 2/11/21 5:16 PM, Andre Przywara wrote:
> > 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.  
> 
> Not necessarily. ioport__unregister_all() removes the ioports added by
> x86/ioport.c::ioport__setup_arch(), *plus* ioports added by different devices,
> like serial, rtc, virtio-pci and vfio-pci (which are used by arm/arm64).

Right, indeed. Not that it really matters, since we are about to exit
anyway, but it looks indeed I need to move this to a generic teardown
method, or actually just keep that part here in this file.

Will give this a try.

Thanks!
Andre

> >
> > 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);    


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