On 5/7/2024 4:23 AM, Alejandro Jimenez wrote:
> Use the tracing infrastructure helper __print_flags() for printing flag
> bitfields, to enhance the trace output by displaying a string describing
> each of the inhibit reasons set.
>
> The kvm_apicv_inhibit_changed tracepoint currently shows the raw bitmap
> value, requiring the user to consult the source file where the inhibit
> reasons are defined to decode the trace output.
>
> Co-developed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Vasant Hegde <vasant.hegde@xxxxxxx>
-Vasant
> ---
> arch/x86/include/asm/kvm_host.h | 19 +++++++++++++++++++
> arch/x86/kvm/trace.h | 9 +++++++--
> arch/x86/kvm/x86.c | 4 ++++
> 3 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 1d13e3cd1dc5..08f83efd12ff 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1273,8 +1273,27 @@ enum kvm_apicv_inhibit {
> * mapping between logical ID and vCPU.
> */
> APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED,
> +
> + NR_APICV_INHIBIT_REASONS,
> };
>
> +#define __APICV_INHIBIT_REASON(reason) \
> + { BIT(APICV_INHIBIT_REASON_##reason), #reason }
> +
> +#define APICV_INHIBIT_REASONS \
> + __APICV_INHIBIT_REASON(DISABLE), \
> + __APICV_INHIBIT_REASON(HYPERV), \
> + __APICV_INHIBIT_REASON(ABSENT), \
> + __APICV_INHIBIT_REASON(BLOCKIRQ), \
> + __APICV_INHIBIT_REASON(PHYSICAL_ID_ALIASED), \
> + __APICV_INHIBIT_REASON(APIC_ID_MODIFIED), \
> + __APICV_INHIBIT_REASON(APIC_BASE_MODIFIED), \
> + __APICV_INHIBIT_REASON(NESTED), \
> + __APICV_INHIBIT_REASON(IRQWIN), \
> + __APICV_INHIBIT_REASON(PIT_REINJ), \
> + __APICV_INHIBIT_REASON(SEV), \
> + __APICV_INHIBIT_REASON(LOGICAL_ID_ALIASED)
> +
> struct kvm_arch {
> unsigned long n_used_mmu_pages;
> unsigned long n_requested_mmu_pages;
> diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
> index 9d0b02ef307e..f23fb9a6776e 100644
> --- a/arch/x86/kvm/trace.h
> +++ b/arch/x86/kvm/trace.h
> @@ -1375,6 +1375,10 @@ TRACE_EVENT(kvm_hv_stimer_cleanup,
> __entry->vcpu_id, __entry->timer_index)
> );
>
> +#define kvm_print_apicv_inhibit_reasons(inhibits) \
> + (inhibits), (inhibits) ? " " : "", \
> + (inhibits) ? __print_flags(inhibits, "|", APICV_INHIBIT_REASONS) : ""
> +
> TRACE_EVENT(kvm_apicv_inhibit_changed,
> TP_PROTO(int reason, bool set, unsigned long inhibits),
> TP_ARGS(reason, set, inhibits),
> @@ -1391,9 +1395,10 @@ TRACE_EVENT(kvm_apicv_inhibit_changed,
> __entry->inhibits = inhibits;
> ),
>
> - TP_printk("%s reason=%u, inhibits=0x%lx",
> + TP_printk("%s reason=%u, inhibits=0x%lx%s%s",
> __entry->set ? "set" : "cleared",
> - __entry->reason, __entry->inhibits)
> + __entry->reason,
> + kvm_print_apicv_inhibit_reasons(__entry->inhibits))
> );
>
> TRACE_EVENT(kvm_apicv_accept_irq,
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b389129d59a9..597ff748f955 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -10011,6 +10011,10 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_apicv_activated);
> static void set_or_clear_apicv_inhibit(unsigned long *inhibits,
> enum kvm_apicv_inhibit reason, bool set)
> {
> + const struct trace_print_flags apicv_inhibits[] = { APICV_INHIBIT_REASONS };
> +
> + BUILD_BUG_ON(ARRAY_SIZE(apicv_inhibits) != NR_APICV_INHIBIT_REASONS);
> +
> if (set)
> __set_bit(reason, inhibits);
> else
