diff mbox

[v4,4/5] KVM: introduce kvm_arch functions for IRQ bypass

Message ID 1438622444-25444-5-git-send-email-eric.auger@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Auger Aug. 3, 2015, 5:20 p.m. UTC 
This patch introduces
- kvm_arch_irq_bypass_add_producer
- kvm_arch_irq_bypass_del_producer
- kvm_arch_irq_bypass_stop
- kvm_arch_irq_bypass_start

They make possible to specialize the KVM IRQ bypass consumer in
case CONFIG_KVM_HAVE_IRQ_BYPASS is set.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Feng Wu <feng.wu@intel.com>

---

v2 -> v3 (Feng Wu):
- use 'kvm_arch_irq_bypass_start' instead of 'kvm_arch_irq_bypass_resume'
- Remove 'kvm_arch_irq_bypass_update', which is not needed to be
  a irqbypass callback per Alex's comments.
- Make kvm_arch_irq_bypass_add_producer return 'int'

v1 -> v2:
- use CONFIG_KVM_HAVE_IRQ_BYPASS instead CONFIG_IRQ_BYPASS_MANAGER
- rename all functions according to Paolo's proposal
- add kvm_arch_irq_bypass_update according to Feng's need
---
 include/linux/kvm_host.h | 33 +++++++++++++++++++++++++++++++++
 virt/kvm/Kconfig         |  3 +++
 2 files changed, 36 insertions(+)

Comments

Alex Williamson Aug. 7, 2015, 8:09 p.m. UTC | #1 
On Mon, 2015-08-03 at 19:20 +0200, Eric Auger wrote:
> This patch introduces
> - kvm_arch_irq_bypass_add_producer
> - kvm_arch_irq_bypass_del_producer
> - kvm_arch_irq_bypass_stop
> - kvm_arch_irq_bypass_start
> 
> They make possible to specialize the KVM IRQ bypass consumer in
> case CONFIG_KVM_HAVE_IRQ_BYPASS is set.
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> Signed-off-by: Feng Wu <feng.wu@intel.com>
> 
> ---
> 
> v2 -> v3 (Feng Wu):
> - use 'kvm_arch_irq_bypass_start' instead of 'kvm_arch_irq_bypass_resume'
> - Remove 'kvm_arch_irq_bypass_update', which is not needed to be
>   a irqbypass callback per Alex's comments.
> - Make kvm_arch_irq_bypass_add_producer return 'int'
> 
> v1 -> v2:
> - use CONFIG_KVM_HAVE_IRQ_BYPASS instead CONFIG_IRQ_BYPASS_MANAGER
> - rename all functions according to Paolo's proposal
> - add kvm_arch_irq_bypass_update according to Feng's need
> ---
>  include/linux/kvm_host.h | 33 +++++++++++++++++++++++++++++++++
>  virt/kvm/Kconfig         |  3 +++
>  2 files changed, 36 insertions(+)
> 
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 05e99b8..84b5feb 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -24,6 +24,7 @@
>  #include <linux/err.h>
>  #include <linux/irqflags.h>
>  #include <linux/context_tracking.h>
> +#include <linux/irqbypass.h>
>  #include <asm/signal.h>
>  
>  #include <linux/kvm.h>
> @@ -1151,5 +1152,37 @@ static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
>  {
>  }
>  #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
> +
> +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
> +
> +int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
> +			   struct irq_bypass_producer *);
> +void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *,
> +			   struct irq_bypass_producer *);
> +void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *);
> +void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *);
> +
> +#else

Do we really need static inline stubs?  When would they get used?  How
would they work since we call them via function pointers?

> +
> +static inline int kvm_arch_irq_bypass_add_producer(
> +			struct irq_bypass_consumer *cons,
> +			struct irq_bypass_producer *prod)
> +{
> +	return -1;

No reason not to stick with standard errno values, is there?  -EINVAL
Thanks,

Alex

> +}
> +static inline void kvm_arch_irq_bypass_del_producer(
> +			struct irq_bypass_consumer *cons,
> +			struct irq_bypass_producer *prod)
> +{
> +}
> +static inline void kvm_arch_irq_bypass_stop(
> +			struct irq_bypass_consumer *cons)
> +{
> +}
> +static inline void kvm_arch_irq_bypass_start(
> +			struct irq_bypass_consumer *cons)
> +{
> +}
> +#endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */
>  #endif
>  
> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
> index e2c876d..9f8014d 100644
> --- a/virt/kvm/Kconfig
> +++ b/virt/kvm/Kconfig
> @@ -47,3 +47,6 @@ config KVM_GENERIC_DIRTYLOG_READ_PROTECT
>  config KVM_COMPAT
>         def_bool y
>         depends on COMPAT && !S390
> +
> +config HAVE_KVM_IRQ_BYPASS
> +       bool
Eric Auger Aug. 10, 2015, 8:43 a.m. UTC | #2 
On 08/07/2015 10:09 PM, Alex Williamson wrote:
> On Mon, 2015-08-03 at 19:20 +0200, Eric Auger wrote:
>> This patch introduces
>> - kvm_arch_irq_bypass_add_producer
>> - kvm_arch_irq_bypass_del_producer
>> - kvm_arch_irq_bypass_stop
>> - kvm_arch_irq_bypass_start
>>
>> They make possible to specialize the KVM IRQ bypass consumer in
>> case CONFIG_KVM_HAVE_IRQ_BYPASS is set.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>> Signed-off-by: Feng Wu <feng.wu@intel.com>
>>
>> ---
>>
>> v2 -> v3 (Feng Wu):
>> - use 'kvm_arch_irq_bypass_start' instead of 'kvm_arch_irq_bypass_resume'
>> - Remove 'kvm_arch_irq_bypass_update', which is not needed to be
>>   a irqbypass callback per Alex's comments.
>> - Make kvm_arch_irq_bypass_add_producer return 'int'
>>
>> v1 -> v2:
>> - use CONFIG_KVM_HAVE_IRQ_BYPASS instead CONFIG_IRQ_BYPASS_MANAGER
>> - rename all functions according to Paolo's proposal
>> - add kvm_arch_irq_bypass_update according to Feng's need
>> ---
>>  include/linux/kvm_host.h | 33 +++++++++++++++++++++++++++++++++
>>  virt/kvm/Kconfig         |  3 +++
>>  2 files changed, 36 insertions(+)
>>
>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
>> index 05e99b8..84b5feb 100644
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -24,6 +24,7 @@
>>  #include <linux/err.h>
>>  #include <linux/irqflags.h>
>>  #include <linux/context_tracking.h>
>> +#include <linux/irqbypass.h>
>>  #include <asm/signal.h>
>>  
>>  #include <linux/kvm.h>
>> @@ -1151,5 +1152,37 @@ static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
>>  {
>>  }
>>  #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
>> +
>> +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
>> +
>> +int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
>> +			   struct irq_bypass_producer *);
>> +void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *,
>> +			   struct irq_bypass_producer *);
>> +void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *);
>> +void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *);
>> +
>> +#else
> 
> Do we really need static inline stubs?  When would they get used?
This addresses the case where another arch would use an irq bypass
producer (such as vfio platform driver ) and irqfd without
implementing/needing forwarding/posting stuff.

I see 2 solutions: either we have those stubs or in eventfd.c we guard
	irq_bypass_unregister_consumer(&irqfd->consumer);
and
	ret = irq_bypass_register_consumer(&irqfd->consumer);
by

#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
#endif

This latter solution maybe is better.

  How
> would they work since we call them via function pointers?
Just tested that without the ARM forwarding implementation of kvm_arch
functions and that runs fine.
> 
>> +
>> +static inline int kvm_arch_irq_bypass_add_producer(
>> +			struct irq_bypass_consumer *cons,
>> +			struct irq_bypass_producer *prod)
>> +{
>> +	return -1;
> 
> No reason not to stick with standard errno values, is there?  -EINVAL
> Thanks,
sure

Thanks

Eric
> 
> Alex
> 
>> +}
>> +static inline void kvm_arch_irq_bypass_del_producer(
>> +			struct irq_bypass_consumer *cons,
>> +			struct irq_bypass_producer *prod)
>> +{
>> +}
>> +static inline void kvm_arch_irq_bypass_stop(
>> +			struct irq_bypass_consumer *cons)
>> +{
>> +}
>> +static inline void kvm_arch_irq_bypass_start(
>> +			struct irq_bypass_consumer *cons)
>> +{
>> +}
>> +#endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */
>>  #endif
>>  
>> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
>> index e2c876d..9f8014d 100644
>> --- a/virt/kvm/Kconfig
>> +++ b/virt/kvm/Kconfig
>> @@ -47,3 +47,6 @@ config KVM_GENERIC_DIRTYLOG_READ_PROTECT
>>  config KVM_COMPAT
>>         def_bool y
>>         depends on COMPAT && !S390
>> +
>> +config HAVE_KVM_IRQ_BYPASS
>> +       bool
> 
> 
>
diff mbox

Patch

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 05e99b8..84b5feb 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -24,6 +24,7 @@ 
 #include <linux/err.h>
 #include <linux/irqflags.h>
 #include <linux/context_tracking.h>
+#include <linux/irqbypass.h>
 #include <asm/signal.h>
 
 #include <linux/kvm.h>
@@ -1151,5 +1152,37 @@  static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
 {
 }
 #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
+
+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+
+int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
+			   struct irq_bypass_producer *);
+void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *,
+			   struct irq_bypass_producer *);
+void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *);
+void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *);
+
+#else
+
+static inline int kvm_arch_irq_bypass_add_producer(
+			struct irq_bypass_consumer *cons,
+			struct irq_bypass_producer *prod)
+{
+	return -1;
+}
+static inline void kvm_arch_irq_bypass_del_producer(
+			struct irq_bypass_consumer *cons,
+			struct irq_bypass_producer *prod)
+{
+}
+static inline void kvm_arch_irq_bypass_stop(
+			struct irq_bypass_consumer *cons)
+{
+}
+static inline void kvm_arch_irq_bypass_start(
+			struct irq_bypass_consumer *cons)
+{
+}
+#endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */
 #endif
 
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index e2c876d..9f8014d 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -47,3 +47,6 @@  config KVM_GENERIC_DIRTYLOG_READ_PROTECT
 config KVM_COMPAT
        def_bool y
        depends on COMPAT && !S390
+
+config HAVE_KVM_IRQ_BYPASS
+       bool