Re: [PATCH 2/4] kvm: x86: allow set apic and ioapic debug dynamically

From: Paolo Bonzini
Date: Wed Jul 03 2019 - 12:23:09 EST


On 01/07/19 08:21, Yi Wang wrote:
> There are two *_debug() macros in kvm apic source file:
> - ioapic_debug, which is disable using #if 0
> - apic_debug, which is commented
>
> Maybe it's better to control these two macros using CONFIG_KVM_DEBUG,
> which can be set in make menuconfig.
>
> Signed-off-by: Yi Wang <wang.yi59@xxxxxxxxxx>
> ---
> arch/x86/kvm/ioapic.c | 2 +-
> arch/x86/kvm/lapic.c | 5 ++++-
> 2 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
> index 1add1bc..8099253 100644
> --- a/arch/x86/kvm/ioapic.c
> +++ b/arch/x86/kvm/ioapic.c
> @@ -45,7 +45,7 @@
> #include "lapic.h"
> #include "irq.h"
>
> -#if 0
> +#ifdef CONFIG_KVM_DEBUG
> #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
> #else
> #define ioapic_debug(fmt, arg...)
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 4924f83..dfff5c6 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -54,8 +54,11 @@
> #define PRIu64 "u"
> #define PRIo64 "o"
>
> -/* #define apic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) */
> +#ifdef CONFIG_KVM_DEBUG
> +#define apic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
> +#else
> #define apic_debug(fmt, arg...) do {} while (0)
> +#endif
>
> /* 14 is the version for Xeon and Pentium 8.4.8*/
> #define APIC_VERSION (0x14UL | ((KVM_APIC_LVT_NUM - 1) << 16))
>

I would just drop all of them. I've never used them in years, the kvm
tracepoints are enough.

Paolo