From: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
To: kvm@vger.kernel.org
Cc: seanjc@google.com, pbonzini@redhat.com,
linux-kernel@vger.kernel.org, suravee.suthikulpanit@amd.com,
vashegde@amd.com, mlevitsk@redhat.com, joao.m.martins@oracle.com,
boris.ostrovsky@oracle.com, mark.kanda@oracle.com,
alejandro.j.jimenez@oracle.com
Subject: [PATCH 4/4] KVM: x86: Add vCPU stat for APICv interrupt injections causing #VMEXIT
Date: Mon, 29 Apr 2024 15:57:38 +0000 [thread overview]
Message-ID: <20240429155738.990025-5-alejandro.j.jimenez@oracle.com> (raw)
In-Reply-To: <20240429155738.990025-1-alejandro.j.jimenez@oracle.com>
Even when APICv/AVIC is active, certain guest accesses to its local APIC(s)
cannot be fully accelerated, and cause a #VMEXIT to allow the VMM to
emulate the behavior and side effects. Expose a counter stat for these
specific #VMEXIT types.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm/avic.c | 7 +++++++
arch/x86/kvm/vmx/vmx.c | 2 ++
arch/x86/kvm/x86.c | 1 +
4 files changed, 11 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e7e3213cefae..388979dfe9f3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1576,6 +1576,7 @@ struct kvm_vcpu_stat {
u64 guest_mode;
u64 notify_window_exits;
u64 apicv_active;
+ u64 apicv_unaccelerated_inj;
};
struct x86_instruction_info;
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 4b74ea91f4e6..274041d3cf66 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -517,6 +517,8 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
kvm_apic_write_nodecode(vcpu, APIC_ICR);
else
kvm_apic_send_ipi(apic, icrl, icrh);
+
+ ++vcpu->stat.apicv_unaccelerated_inj;
break;
case AVIC_IPI_FAILURE_TARGET_NOT_RUNNING:
/*
@@ -525,6 +527,8 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
* vcpus. So, we just need to kick the appropriate vcpu.
*/
avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index);
+
+ ++vcpu->stat.apicv_unaccelerated_inj;
break;
case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE:
WARN_ONCE(1, "Invalid backing page\n");
@@ -704,6 +708,9 @@ int avic_unaccelerated_access_interception(struct kvm_vcpu *vcpu)
trace_kvm_avic_unaccelerated_access(vcpu->vcpu_id, offset,
trap, write, vector);
+
+ ++vcpu->stat.apicv_unaccelerated_inj;
+
if (trap) {
/* Handling Trap */
WARN_ONCE(!write, "svm: Handling trap read.\n");
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f10b5f8f364b..a7487f12ded1 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5657,6 +5657,8 @@ static int handle_apic_write(struct kvm_vcpu *vcpu)
{
unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
+ ++vcpu->stat.apicv_unaccelerated_inj;
+
/*
* APIC-write VM-Exit is trap-like, KVM doesn't need to advance RIP and
* hardware has done any necessary aliasing, offset adjustments, etc...
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 03cb933920cb..c8730b0fac87 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -307,6 +307,7 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_IBOOLEAN(VCPU, guest_mode),
STATS_DESC_COUNTER(VCPU, notify_window_exits),
STATS_DESC_IBOOLEAN(VCPU, apicv_active),
+ STATS_DESC_COUNTER(VCPU, apicv_unaccelerated_inj),
};
const struct kvm_stats_header kvm_vcpu_stats_header = {
--
2.39.3
prev parent reply other threads:[~2024-04-29 15:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 15:57 [PATCH 0/4] Export APICv-related state via binary stats interface Alejandro Jimenez
2024-04-29 15:57 ` [PATCH 1/4] KVM: x86: Expose per-vCPU APICv status Alejandro Jimenez
2024-04-29 15:57 ` [PATCH 2/4] KVM: x86: Add a VM stat exposing when SynIC AutoEOI is in use Alejandro Jimenez
2024-04-29 15:57 ` [PATCH 3/4] KVM: x86: Add a VM stat exposing when KVM PIT is set to reinject mode Alejandro Jimenez
2024-04-29 15:57 ` Alejandro Jimenez [this message]
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