Re: [Qemu-devel] [RFC PATCH 1/3] KVM: s390: Move out initialization code.

[Cornelia Huck]

On Thu, 21 Feb 2013 15:43:55 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Thu, Feb 21, 2013 at 02:12:58PM +0100, Cornelia Huck wrote:
> > kvm-s390's module initialization code needs to live in a separate
> > module (kvm-s390.ko) if we want to include eventfd (which has its
> > own module init func).
> > 
> > Signed-off-by: Cornelia Huck <address@hidden>
> 
> I don't get this explanation.
> What's the problem this solves?
> Could you clarify please?

On s390, we currently build a single 'kvm' module, with a module_init
function. eventfd has its own module_init function, and we can't have
two of them in the same module. I just moved our specific module
initialization into a new 'kvm_s390' module.

> 
> > ---
> >  arch/s390/kvm/Makefile   |  4 +++-
> >  arch/s390/kvm/init.c     | 52 
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> >  arch/s390/kvm/kvm-s390.c | 38 ++++-------------------------------
> >  3 files changed, 59 insertions(+), 35 deletions(-)
> >  create mode 100644 arch/s390/kvm/init.c
> > 
> > diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> > index 3975722..2441ffd 100644
> > --- a/arch/s390/kvm/Makefile
> > +++ b/arch/s390/kvm/Makefile
> > @@ -11,4 +11,6 @@ common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
> >  ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> >  
> >  kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o 
> > sigp.o diag.o
> > -obj-$(CONFIG_KVM) += kvm.o
> > +kvm_s390-objs := init.o
> > +
> > +obj-$(CONFIG_KVM) += kvm.o kvm_s390.o
> > diff --git a/arch/s390/kvm/init.c b/arch/s390/kvm/init.c
> > new file mode 100644
> > index 0000000..dc4028a
> > --- /dev/null
> > +++ b/arch/s390/kvm/init.c
> > @@ -0,0 +1,52 @@
> > +/*
> > + * kvm on s390 module initialization
> > + *
> > + * Copyright IBM Corp. 2013
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License (version 2 only)
> > + * as published by the Free Software Foundation.
> > + *
> > + *    Author(s): Cornelia Huck <address@hidden>
> > + */
> > +
> > +#include <linux/kvm.h>
> > +#include <linux/kvm_host.h>
> > +#include <linux/module.h>
> > +#include "kvm-s390.h"
> > +
> > +extern unsigned long long *facilities;
> > +
> > +static int __init kvm_s390_init(void)
> > +{
> > +   int ret;
> > +   ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> > +   if (ret)
> > +           return ret;
> > +
> > +   /*
> > +    * guests can ask for up to 255+1 double words, we need a full page
> > +    * to hold the maximum amount of facilities. On the other hand, we
> > +    * only set facilities that are known to work in KVM.
> > +    */
> > +   facilities = (unsigned long long *) get_zeroed_page(GFP_KERNEL|GFP_DMA);
> > +   if (!facilities) {
> > +           kvm_exit();
> > +           return -ENOMEM;
> > +   }
> > +   memcpy(facilities, S390_lowcore.stfle_fac_list, 16);
> > +   facilities[0] &= 0xff00fff3f47c0000ULL;
> > +   facilities[1] &= 0x001c000000000000ULL;
> > +   return 0;
> > +}
> > +
> > +static void __exit kvm_s390_exit(void)
> > +{
> > +   free_page((unsigned long) facilities);
> > +   kvm_exit();
> > +}
> > +
> > +module_init(kvm_s390_init);
> > +module_exit(kvm_s390_exit);
> > +
> > +MODULE_LICENSE("GPL");
> 
> GPL v2?
> 
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index f822d36..58a5f03 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -36,6 +36,9 @@
> >  #include "trace.h"
> >  #include "trace-s390.h"
> >  
> > +unsigned long long *facilities;
> > +EXPORT_SYMBOL_GPL(facilities);
> > +
> >  #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
> >  
> >  struct kvm_stats_debugfs_item debugfs_entries[] = {
> > @@ -83,8 +86,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
> >     { NULL }
> >  };
> >  
> > -static unsigned long long *facilities;
> > -
> >  /* Section: not file related */
> >  int kvm_arch_hardware_enable(void *garbage)
> >  {
> > @@ -823,6 +824,7 @@ int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, 
> > unsigned long addr)
> >             return -EFAULT;
> >     return 0;
> >  }
> > +EXPORT_SYMBOL_GPL(kvm_s390_vcpu_store_status);
> >  
> >  static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
> >                                  struct kvm_enable_cap *cap)
> > @@ -1026,35 +1028,3 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
> >                                struct kvm_memory_slot *slot)
> >  {
> >  }
> > -
> > -static int __init kvm_s390_init(void)
> > -{
> > -   int ret;
> > -   ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> > -   if (ret)
> > -           return ret;
> > -
> > -   /*
> > -    * guests can ask for up to 255+1 double words, we need a full page
> > -    * to hold the maximum amount of facilities. On the other hand, we
> > -    * only set facilities that are known to work in KVM.
> > -    */
> > -   facilities = (unsigned long long *) get_zeroed_page(GFP_KERNEL|GFP_DMA);
> > -   if (!facilities) {
> > -           kvm_exit();
> > -           return -ENOMEM;
> > -   }
> > -   memcpy(facilities, S390_lowcore.stfle_fac_list, 16);
> > -   facilities[0] &= 0xff00fff3f47c0000ULL;
> > -   facilities[1] &= 0x001c000000000000ULL;
> > -   return 0;
> > -}
> > -
> > -static void __exit kvm_s390_exit(void)
> > -{
> > -   free_page((unsigned long) facilities);
> > -   kvm_exit();
> > -}
> > -
> > -module_init(kvm_s390_init);
> > -module_exit(kvm_s390_exit);
> > -- 
> > 1.7.12.4
> > 
> > --
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