Re: [PATCH] KVM: x86: avoid misreporting level-triggered irqs as edge-triggered in tracing

From: Paolo Bonzini
Date: Thu Apr 11 2019 - 09:14:59 EST


On 27/03/19 15:12, Vitaly Kuznetsov wrote:
> In __apic_accept_irq() interface trig_mode is int and actually on some code
> paths it is set above u8:
>
> kvm_apic_set_irq() extracts it from 'struct kvm_lapic_irq' where trig_mode
> is u16. This is done on purpose as e.g. kvm_set_msi_irq() sets it to
> (1 << 15) & e->msi.data
>
> kvm_apic_local_deliver sets it to reg & (1 << 15).
>
> Fix the immediate issue by making 'tm' into u16. We may also want to adjust
> __apic_accept_irq() interface and use proper sizes for vector, level,
> trig_mode but this is not urgent.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---
> arch/x86/kvm/trace.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
> index 6432d08c7de7..4d47a2631d1f 100644
> --- a/arch/x86/kvm/trace.h
> +++ b/arch/x86/kvm/trace.h
> @@ -438,13 +438,13 @@ TRACE_EVENT(kvm_apic_ipi,
> );
>
> TRACE_EVENT(kvm_apic_accept_irq,
> - TP_PROTO(__u32 apicid, __u16 dm, __u8 tm, __u8 vec),
> + TP_PROTO(__u32 apicid, __u16 dm, __u16 tm, __u8 vec),
> TP_ARGS(apicid, dm, tm, vec),
>
> TP_STRUCT__entry(
> __field( __u32, apicid )
> __field( __u16, dm )
> - __field( __u8, tm )
> + __field( __u16, tm )
> __field( __u8, vec )
> ),
>
>

Queued, thanks.

Paolo