Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] kvm: svm: Introduce GA Log tracepoint for AVIC
To:     Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc:     joro@8bytes.org, jon.grimm@amd.com
References: <1584009568-14089-1-git-send-email-suravee.suthikulpanit@amd.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <66820077-421a-1807-4ee8-588fb380c34d@redhat.com>
Date:   Sat, 14 Mar 2020 11:58:36 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.5.0
MIME-Version: 1.0
In-Reply-To: <1584009568-14089-1-git-send-email-suravee.suthikulpanit@amd.com>
Content-Type: text/plain; charset=windows-1252
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 12/03/20 11:39, Suravee Suthikulpanit wrote:
> GA Log tracepoint is useful when debugging AVIC performance
> issue as it can be used with perf to count the number of times
> IOMMU AVIC injects interrupts through the slow-path instead of
> directly inject interrupts to the target vcpu.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> ---
>  arch/x86/kvm/svm.c   |  1 +
>  arch/x86/kvm/trace.h | 18 ++++++++++++++++++
>  arch/x86/kvm/x86.c   |  1 +
>  3 files changed, 20 insertions(+)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 24c0b2b..504f2cb 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1208,6 +1208,7 @@ static int avic_ga_log_notifier(u32 ga_tag)
>  	u32 vcpu_id = AVIC_GATAG_TO_VCPUID(ga_tag);
>  
>  	pr_debug("SVM: %s: vm_id=%#x, vcpu_id=%#x\n", __func__, vm_id, vcpu_id);
> +	trace_kvm_avic_ga_log(vm_id, vcpu_id);
>  
>  	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
>  	hash_for_each_possible(svm_vm_data_hash, kvm_svm, hnode, vm_id) {
> diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
> index f194dd0..023de6c 100644
> --- a/arch/x86/kvm/trace.h
> +++ b/arch/x86/kvm/trace.h
> @@ -1367,6 +1367,24 @@
>  		  __entry->vec)
>  );
>  
> +TRACE_EVENT(kvm_avic_ga_log,
> +	    TP_PROTO(u32 vmid, u32 vcpuid),
> +	    TP_ARGS(vmid, vcpuid),
> +
> +	TP_STRUCT__entry(
> +		__field(u32, vmid)
> +		__field(u32, vcpuid)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->vmid = vmid;
> +		__entry->vcpuid = vcpuid;
> +	),
> +
> +	TP_printk("vmid=%u, vcpuid=%u",
> +		  __entry->vmid, __entry->vcpuid)
> +);
> +
>  TRACE_EVENT(kvm_hv_timer_state,
>  		TP_PROTO(unsigned int vcpu_id, unsigned int hv_timer_in_use),
>  		TP_ARGS(vcpu_id, hv_timer_in_use),
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 5de2006..ef38b82 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -10514,4 +10514,5 @@ u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu)
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_ga_log);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_apicv_update_request);
> 

Queued, thanks.

Paolo