[PATCH] kvm: Correct documentation of kvm_irqchip_*()

[PATCH] kvm: Correct documentation of kvm_irqchip_*()

[Eduardo Habkost]

When split irqchip support was introduced, the meaning of
kvm_irqchip_in_kernel() changed: now it only means the LAPIC is
in kernel.  The PIC, IOAPIC, and PIT might be in userspace if
irqchip=split was set.  Update the doc comment to reflect that.

While at it, remove the "the user asked us" part in
kvm_irqchip_is_split() doc comment.  That macro has nothing to do
with existence of explicit user-provided options.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 include/sysemu/kvm.h | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 5bbea538830..23fce48b0be 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -51,23 +51,22 @@ extern bool kvm_msi_use_devid;
 /**
  * kvm_irqchip_in_kernel:
  *
- * Returns: true if the user asked us to create an in-kernel
- * irqchip via the "kernel_irqchip=on" machine option.
+ * Returns: true if an in-kernel irqchip was created.
  * What this actually means is architecture and machine model
- * specific: on PC, for instance, it means that the LAPIC,
- * IOAPIC and PIT are all in kernel. This function should never
- * be used from generic target-independent code: use one of the
- * following functions or some other specific check instead.
+ * specific: on PC, for instance, it means that the LAPIC
+ * is in kernel.  This function should never be used from generic
+ * target-independent code: use one of the following functions or
+ * some other specific check instead.
  */
 #define kvm_irqchip_in_kernel() (kvm_kernel_irqchip)
 
 /**
  * kvm_irqchip_is_split:
  *
- * Returns: true if the user asked us to split the irqchip
- * implementation between user and kernel space. The details are
- * architecture and machine specific. On PC, it means that the PIC,
- * IOAPIC, and PIT are in user space while the LAPIC is in the kernel.
+ * Returns: true if the irqchip implementation is split between
+ * user and kernel space.  The details are architecture and
+ * machine specific.  On PC, it means that the PIC, IOAPIC, and
+ * PIT are in user space while the LAPIC is in the kernel.
  */
 #define kvm_irqchip_is_split() (kvm_split_irqchip)
 
-- 
2.26.2

Re: [PATCH] kvm: Correct documentation of kvm_irqchip_*()

[Paolo Bonzini]

On 22/09/20 22:36, Eduardo Habkost wrote:
> When split irqchip support was introduced, the meaning of
> kvm_irqchip_in_kernel() changed: now it only means the LAPIC is
> in kernel.  The PIC, IOAPIC, and PIT might be in userspace if
> irqchip=split was set.  Update the doc comment to reflect that.
> 
> While at it, remove the "the user asked us" part in
> kvm_irqchip_is_split() doc comment.  That macro has nothing to do
> with existence of explicit user-provided options.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  include/sysemu/kvm.h | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)
> 
> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> index 5bbea538830..23fce48b0be 100644
> --- a/include/sysemu/kvm.h
> +++ b/include/sysemu/kvm.h
> @@ -51,23 +51,22 @@ extern bool kvm_msi_use_devid;
>  /**
>   * kvm_irqchip_in_kernel:
>   *
> - * Returns: true if the user asked us to create an in-kernel
> - * irqchip via the "kernel_irqchip=on" machine option.
> + * Returns: true if an in-kernel irqchip was created.
>   * What this actually means is architecture and machine model
> - * specific: on PC, for instance, it means that the LAPIC,
> - * IOAPIC and PIT are all in kernel. This function should never
> - * be used from generic target-independent code: use one of the
> - * following functions or some other specific check instead.
> + * specific: on PC, for instance, it means that the LAPIC
> + * is in kernel.  This function should never be used from generic
> + * target-independent code: use one of the following functions or
> + * some other specific check instead.
>   */
>  #define kvm_irqchip_in_kernel() (kvm_kernel_irqchip)
>  
>  /**
>   * kvm_irqchip_is_split:
>   *
> - * Returns: true if the user asked us to split the irqchip
> - * implementation between user and kernel space. The details are
> - * architecture and machine specific. On PC, it means that the PIC,
> - * IOAPIC, and PIT are in user space while the LAPIC is in the kernel.
> + * Returns: true if the irqchip implementation is split between
> + * user and kernel space.  The details are architecture and
> + * machine specific.  On PC, it means that the PIC, IOAPIC, and
> + * PIT are in user space while the LAPIC is in the kernel.
>   */
>  #define kvm_irqchip_is_split() (kvm_split_irqchip)
>  
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>