[25/44] KVM: s390: Do s390 specific init without bouncing through kvm_init()

Message ID 20221102231911.3107438-26-seanjc@google.com
State New
Headers
Series KVM: Rework kvm_init() and hardware enabling |

Commit Message

Sean Christopherson Nov. 2, 2022, 11:18 p.m. UTC
  Move the guts of kvm_arch_init() into a new helper, __kvm_s390_init(),
and invoke the new helper directly from kvm_s390_init() instead of
bouncing through kvm_init().  Invoking kvm_arch_init() is the very
first action performed by kvm_init(), i.e. this is a glorified nop.

Moving setup to __kvm_s390_init() will allow tagging more functions as
__init, and emptying kvm_arch_init() will allow dropping the hook
entirely once all architecture implementations are nops.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/s390/kvm/kvm-s390.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)
  

Comments

Philippe Mathieu-Daudé Nov. 3, 2022, 7:16 a.m. UTC | #1
On 3/11/22 00:18, Sean Christopherson wrote:
> Move the guts of kvm_arch_init() into a new helper, __kvm_s390_init(),
> and invoke the new helper directly from kvm_s390_init() instead of
> bouncing through kvm_init().  Invoking kvm_arch_init() is the very
> first action performed by kvm_init(), i.e. this is a glorified nop.
> 
> Moving setup to __kvm_s390_init() will allow tagging more functions as
> __init, and emptying kvm_arch_init() will allow dropping the hook
> entirely once all architecture implementations are nops.
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>   arch/s390/kvm/kvm-s390.c | 29 +++++++++++++++++++++++++----
>   1 file changed, 25 insertions(+), 4 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
  
Claudio Imbrenda Nov. 3, 2022, 12:44 p.m. UTC | #2
On Wed,  2 Nov 2022 23:18:52 +0000
Sean Christopherson <seanjc@google.com> wrote:

> Move the guts of kvm_arch_init() into a new helper, __kvm_s390_init(),
> and invoke the new helper directly from kvm_s390_init() instead of
> bouncing through kvm_init().  Invoking kvm_arch_init() is the very
> first action performed by kvm_init(), i.e. this is a glorified nop.
> 
> Moving setup to __kvm_s390_init() will allow tagging more functions as
> __init, and emptying kvm_arch_init() will allow dropping the hook
> entirely once all architecture implementations are nops.
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  arch/s390/kvm/kvm-s390.c | 29 +++++++++++++++++++++++++----
>  1 file changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 7fcd2d3b3558..e1c9980aae78 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -461,7 +461,7 @@ static void kvm_s390_cpu_feat_init(void)
>  	 */
>  }
>  
> -int kvm_arch_init(void *opaque)
> +static int __kvm_s390_init(void)
>  {
>  	int rc = -ENOMEM;
>  
> @@ -519,7 +519,7 @@ int kvm_arch_init(void *opaque)
>  	return rc;
>  }
>  
> -void kvm_arch_exit(void)
> +static void __kvm_s390_exit(void)
>  {
>  	gmap_unregister_pte_notifier(&gmap_notifier);
>  	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
> @@ -533,6 +533,16 @@ void kvm_arch_exit(void)
>  	debug_unregister(kvm_s390_dbf_uv);
>  }
>  
> +int kvm_arch_init(void *opaque)
> +{
> +	return 0;
> +}
> +
> +void kvm_arch_exit(void)
> +{
> +
> +}
> +

I wonder at this point if it's possible to define kvm_arch_init and
kvm_arch_exit directly in kvm_main.c with __weak

>  /* Section: device related */
>  long kvm_arch_dev_ioctl(struct file *filp,
>  			unsigned int ioctl, unsigned long arg)
> @@ -5634,7 +5644,7 @@ static inline unsigned long nonhyp_mask(int i)
>  
>  static int __init kvm_s390_init(void)
>  {
> -	int i;
> +	int i, r;
>  
>  	if (!sclp.has_sief2) {
>  		pr_info("SIE is not available\n");
> @@ -5650,12 +5660,23 @@ static int __init kvm_s390_init(void)
>  		kvm_s390_fac_base[i] |=
>  			stfle_fac_list[i] & nonhyp_mask(i);
>  
> -	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +	r = __kvm_s390_init();
> +	if (r)
> +		return r;
> +
> +	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +	if (r) {
> +		__kvm_s390_exit();
> +		return r;
> +	}
> +	return 0;
>  }
>  
>  static void __exit kvm_s390_exit(void)
>  {
>  	kvm_exit();
> +
> +	__kvm_s390_exit();
>  }
>  
>  module_init(kvm_s390_init);
  
Claudio Imbrenda Nov. 3, 2022, 1:21 p.m. UTC | #3
On Thu, 3 Nov 2022 13:44:15 +0100
Claudio Imbrenda <imbrenda@linux.ibm.com> wrote:

> On Wed,  2 Nov 2022 23:18:52 +0000
> Sean Christopherson <seanjc@google.com> wrote:
> 
> > Move the guts of kvm_arch_init() into a new helper, __kvm_s390_init(),
> > and invoke the new helper directly from kvm_s390_init() instead of
> > bouncing through kvm_init().  Invoking kvm_arch_init() is the very
> > first action performed by kvm_init(), i.e. this is a glorified nop.
> > 
> > Moving setup to __kvm_s390_init() will allow tagging more functions as
> > __init, and emptying kvm_arch_init() will allow dropping the hook
> > entirely once all architecture implementations are nops.
> > 
> > No functional change intended.
> > 
> > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > ---
> >  arch/s390/kvm/kvm-s390.c | 29 +++++++++++++++++++++++++----
> >  1 file changed, 25 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 7fcd2d3b3558..e1c9980aae78 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -461,7 +461,7 @@ static void kvm_s390_cpu_feat_init(void)
> >  	 */
> >  }
> >  
> > -int kvm_arch_init(void *opaque)
> > +static int __kvm_s390_init(void)
> >  {
> >  	int rc = -ENOMEM;
> >  
> > @@ -519,7 +519,7 @@ int kvm_arch_init(void *opaque)
> >  	return rc;
> >  }
> >  
> > -void kvm_arch_exit(void)
> > +static void __kvm_s390_exit(void)
> >  {
> >  	gmap_unregister_pte_notifier(&gmap_notifier);
> >  	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
> > @@ -533,6 +533,16 @@ void kvm_arch_exit(void)
> >  	debug_unregister(kvm_s390_dbf_uv);
> >  }
> >  
> > +int kvm_arch_init(void *opaque)
> > +{
> > +	return 0;
> > +}
> > +
> > +void kvm_arch_exit(void)
> > +{
> > +
> > +}
> > +  
> 
> I wonder at this point if it's possible to define kvm_arch_init and
> kvm_arch_exit directly in kvm_main.c with __weak

ah, nevermind, you get rid of them completely in the next patch

> 
> >  /* Section: device related */
> >  long kvm_arch_dev_ioctl(struct file *filp,
> >  			unsigned int ioctl, unsigned long arg)
> > @@ -5634,7 +5644,7 @@ static inline unsigned long nonhyp_mask(int i)
> >  
> >  static int __init kvm_s390_init(void)
> >  {
> > -	int i;
> > +	int i, r;
> >  
> >  	if (!sclp.has_sief2) {
> >  		pr_info("SIE is not available\n");
> > @@ -5650,12 +5660,23 @@ static int __init kvm_s390_init(void)
> >  		kvm_s390_fac_base[i] |=
> >  			stfle_fac_list[i] & nonhyp_mask(i);
> >  
> > -	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> > +	r = __kvm_s390_init();
> > +	if (r)
> > +		return r;
> > +
> > +	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> > +	if (r) {
> > +		__kvm_s390_exit();
> > +		return r;
> > +	}
> > +	return 0;
> >  }
> >  
> >  static void __exit kvm_s390_exit(void)
> >  {
> >  	kvm_exit();
> > +
> > +	__kvm_s390_exit();
> >  }
> >  
> >  module_init(kvm_s390_init);  
>
  
Eric Farman Nov. 7, 2022, 6:22 p.m. UTC | #4
On Wed, 2022-11-02 at 23:18 +0000, Sean Christopherson wrote:
> Move the guts of kvm_arch_init() into a new helper,
> __kvm_s390_init(),
> and invoke the new helper directly from kvm_s390_init() instead of
> bouncing through kvm_init().  Invoking kvm_arch_init() is the very
> first action performed by kvm_init(), i.e. this is a glorified nop.
> 
> Moving setup to __kvm_s390_init() will allow tagging more functions
> as
> __init, and emptying kvm_arch_init() will allow dropping the hook
> entirely once all architecture implementations are nops.
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  arch/s390/kvm/kvm-s390.c | 29 +++++++++++++++++++++++++----
>  1 file changed, 25 insertions(+), 4 deletions(-)

Reviewed-by: Eric Farman <farman@linux.ibm.com>
  

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 7fcd2d3b3558..e1c9980aae78 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -461,7 +461,7 @@  static void kvm_s390_cpu_feat_init(void)
 	 */
 }
 
-int kvm_arch_init(void *opaque)
+static int __kvm_s390_init(void)
 {
 	int rc = -ENOMEM;
 
@@ -519,7 +519,7 @@  int kvm_arch_init(void *opaque)
 	return rc;
 }
 
-void kvm_arch_exit(void)
+static void __kvm_s390_exit(void)
 {
 	gmap_unregister_pte_notifier(&gmap_notifier);
 	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
@@ -533,6 +533,16 @@  void kvm_arch_exit(void)
 	debug_unregister(kvm_s390_dbf_uv);
 }
 
+int kvm_arch_init(void *opaque)
+{
+	return 0;
+}
+
+void kvm_arch_exit(void)
+{
+
+}
+
 /* Section: device related */
 long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg)
@@ -5634,7 +5644,7 @@  static inline unsigned long nonhyp_mask(int i)
 
 static int __init kvm_s390_init(void)
 {
-	int i;
+	int i, r;
 
 	if (!sclp.has_sief2) {
 		pr_info("SIE is not available\n");
@@ -5650,12 +5660,23 @@  static int __init kvm_s390_init(void)
 		kvm_s390_fac_base[i] |=
 			stfle_fac_list[i] & nonhyp_mask(i);
 
-	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	r = __kvm_s390_init();
+	if (r)
+		return r;
+
+	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	if (r) {
+		__kvm_s390_exit();
+		return r;
+	}
+	return 0;
 }
 
 static void __exit kvm_s390_exit(void)
 {
 	kvm_exit();
+
+	__kvm_s390_exit();
 }
 
 module_init(kvm_s390_init);