[PATCH] x86: irq: unconditionally define KVM interrupt vectors

[PATCH] x86: irq: unconditionally define KVM interrupt vectors

[Paolo Bonzini]

Unlike arch/x86/kernel/idt.c, FRED support chose to remove the #ifdefs
from the .c files and concentrate them in the headers, where unused
handlers are #define'd to NULL.

However, the constants for KVM's 3 posted interrupt vectors are still
defined conditionally in irq_vectors.h.  In the tree that FRED support was
developed on, this is innocuous because CONFIG_HAVE_KVM was effectively
always set.  With the cleanups that recently went into the KVM tree to
remove CONFIG_HAVE_KVM, the conditional became IS_ENABLED(CONFIG_KVM).
This causes a linux-next compilation failure in FRED code, when
CONFIG_KVM=n.

In preparation for the merging of FRED in Linux 6.9, define the interrupt
vector numbers unconditionally.

Cc: x86@kernel.org
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Xin Li (Intel) <xin@zytor.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/irq_vectors.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 3f73ac3ed3a0..d18bfb238f66 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -84,11 +84,9 @@
 #define HYPERVISOR_CALLBACK_VECTOR	0xf3
 
 /* Vector for KVM to deliver posted interrupt IPI */
-#if IS_ENABLED(CONFIG_KVM)
 #define POSTED_INTR_VECTOR		0xf2
 #define POSTED_INTR_WAKEUP_VECTOR	0xf1
 #define POSTED_INTR_NESTED_VECTOR	0xf0
-#endif
 
 #define MANAGED_IRQ_SHUTDOWN_VECTOR	0xef
 
-- 
2.39.1

Re: [PATCH] x86: irq: unconditionally define KVM interrupt vectors

[Xin Li]

On 2/23/2024 2:22 AM, Paolo Bonzini wrote:
> Unlike arch/x86/kernel/idt.c, FRED support chose to remove the #ifdefs
> from the .c files and concentrate them in the headers, where unused
> handlers are #define'd to NULL.
> 
> However, the constants for KVM's 3 posted interrupt vectors are still
> defined conditionally in irq_vectors.h.  In the tree that FRED support was
> developed on, this is innocuous because CONFIG_HAVE_KVM was effectively
> always set.  With the cleanups that recently went into the KVM tree to
> remove CONFIG_HAVE_KVM, the conditional became IS_ENABLED(CONFIG_KVM).
> This causes a linux-next compilation failure in FRED code, when
> CONFIG_KVM=n.
> 
> In preparation for the merging of FRED in Linux 6.9, define the interrupt
> vector numbers unconditionally.
> 
> Cc: x86@kernel.org
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Suggested-by: Xin Li (Intel) <xin@zytor.com>
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   arch/x86/include/asm/irq_vectors.h | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
> index 3f73ac3ed3a0..d18bfb238f66 100644
> --- a/arch/x86/include/asm/irq_vectors.h
> +++ b/arch/x86/include/asm/irq_vectors.h
> @@ -84,11 +84,9 @@
>   #define HYPERVISOR_CALLBACK_VECTOR	0xf3
>   
>   /* Vector for KVM to deliver posted interrupt IPI */
> -#if IS_ENABLED(CONFIG_KVM)
>   #define POSTED_INTR_VECTOR		0xf2
>   #define POSTED_INTR_WAKEUP_VECTOR	0xf1
>   #define POSTED_INTR_NESTED_VECTOR	0xf0
> -#endif
>   
>   #define MANAGED_IRQ_SHUTDOWN_VECTOR	0xef
>   

Thank you very much!
     Xin

Re: [PATCH] x86: irq: unconditionally define KVM interrupt vectors

[Thomas Gleixner]

On Fri, Feb 23 2024 at 05:22, Paolo Bonzini wrote:
> Unlike arch/x86/kernel/idt.c, FRED support chose to remove the #ifdefs
> from the .c files and concentrate them in the headers, where unused
> handlers are #define'd to NULL.
>
> However, the constants for KVM's 3 posted interrupt vectors are still
> defined conditionally in irq_vectors.h.  In the tree that FRED support was
> developed on, this is innocuous because CONFIG_HAVE_KVM was effectively
> always set.  With the cleanups that recently went into the KVM tree to
> remove CONFIG_HAVE_KVM, the conditional became IS_ENABLED(CONFIG_KVM).
> This causes a linux-next compilation failure in FRED code, when
> CONFIG_KVM=n.
>
> In preparation for the merging of FRED in Linux 6.9, define the interrupt
> vector numbers unconditionally.
>
> Cc: x86@kernel.org
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Suggested-by: Xin Li (Intel) <xin@zytor.com>
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>