diff mbox series

[v2,2/4] KVM: x86: add more information to the kvm_entry tracepoint

Message ID 20230924124410.897646-3-mlevitsk@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86: tracepoint updates | expand

Commit Message

Maxim Levitsky Sept. 24, 2023, 12:44 p.m. UTC 
Add:
  - Flag showing that VM is in a guest mode on entry.
  - Flag showing that immediate vm exit is set to happen after the entry.
  - VMX/SVM specific interrupt injection info (like in a vm exit).

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 arch/x86/include/asm/kvm-x86-ops.h |  1 +
 arch/x86/include/asm/kvm_host.h    |  5 ++++-
 arch/x86/kvm/svm/svm.c             | 17 +++++++++++++++++
 arch/x86/kvm/trace.h               | 19 +++++++++++++++++--
 arch/x86/kvm/vmx/vmx.c             | 12 ++++++++++++
 5 files changed, 51 insertions(+), 3 deletions(-)

Comments

Paolo Bonzini Sept. 26, 2023, 4:39 p.m. UTC | #1 
On 9/24/23 14:44, Maxim Levitsky wrote:
> +		__field(	u32,		inj_info	)
> +		__field(	u32,		inj_info_err	)
> +		__field(	bool,		guest_mode	)
> +		__field(	bool,		req_imm_exit	)
> +		),

As anticipated in patch 1 I'm not so sure about adding req_imm_exit here 
but also (especially) in kvm_exit.  I do believe it should be traced, 
I'm not sure it's needed in kvm_entry+kvm_exit as opposed to just a 
separate tracepoint.

Paolo
Maxim Levitsky Sept. 28, 2023, 10:41 a.m. UTC | #2 
У вт, 2023-09-26 у 18:39 +0200, Paolo Bonzini пише:
> On 9/24/23 14:44, Maxim Levitsky wrote:
> > +		__field(	u32,		inj_info	)
> > +		__field(	u32,		inj_info_err	)
> > +		__field(	bool,		guest_mode	)
> > +		__field(	bool,		req_imm_exit	)
> > +		),
> 
> As anticipated in patch 1 I'm not so sure about adding req_imm_exit here 
> but also (especially) in kvm_exit.  I do believe it should be traced, 
> I'm not sure it's needed in kvm_entry+kvm_exit as opposed to just a 
> separate tracepoint.


I will drop guest_mode.

Best regards,
	Maxim Levitsky


> 
> Paolo
>
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index f654a7f4cc8c0c..346fed6e3c33aa 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -99,6 +99,7 @@  KVM_X86_OP(get_l2_tsc_multiplier)
 KVM_X86_OP(write_tsc_offset)
 KVM_X86_OP(write_tsc_multiplier)
 KVM_X86_OP(get_exit_info)
+KVM_X86_OP(get_entry_info)
 KVM_X86_OP(check_intercept)
 KVM_X86_OP(handle_exit_irqoff)
 KVM_X86_OP(sched_in)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 383a1d0cc0743b..321721813474f7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1679,13 +1679,16 @@  struct kvm_x86_ops {
 	void (*write_tsc_multiplier)(struct kvm_vcpu *vcpu);
 
 	/*
-	 * Retrieve somewhat arbitrary exit information.  Intended to
+	 * Retrieve somewhat arbitrary exit/entry information.  Intended to
 	 * be used only from within tracepoints or error paths.
 	 */
 	void (*get_exit_info)(struct kvm_vcpu *vcpu, u32 *reason,
 			      u64 *info1, u64 *info2,
 			      u32 *exit_int_info, u32 *exit_int_info_err_code);
 
+	void (*get_entry_info)(struct kvm_vcpu *vcpu,
+				u32 *inj_info, u32 *inj_info_error_code);
+
 	int (*check_intercept)(struct kvm_vcpu *vcpu,
 			       struct x86_instruction_info *info,
 			       enum x86_intercept_stage stage,
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 60b130b7f9d510..cd65c04be3d0e2 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3504,6 +3504,22 @@  static void svm_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
 		*error_code = 0;
 }
 
+static void svm_get_entry_info(struct kvm_vcpu *vcpu,
+			u32 *inj_info,
+			u32 *inj_info_error_code)
+{
+	struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control;
+
+	*inj_info = control->event_inj;
+
+	if ((*inj_info & SVM_EXITINTINFO_VALID) &&
+	    (*inj_info & SVM_EXITINTINFO_VALID_ERR))
+		*inj_info_error_code = control->event_inj_err;
+	else
+		*inj_info_error_code = 0;
+
+}
+
 static int svm_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -4992,6 +5008,7 @@  static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.required_apicv_inhibits = AVIC_REQUIRED_APICV_INHIBITS,
 
 	.get_exit_info = svm_get_exit_info,
+	.get_entry_info = svm_get_entry_info,
 
 	.vcpu_after_set_cpuid = svm_vcpu_after_set_cpuid,
 
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 83843379813ee3..f4c56f59f5c11b 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -21,14 +21,29 @@  TRACE_EVENT(kvm_entry,
 	TP_STRUCT__entry(
 		__field(	unsigned int,	vcpu_id		)
 		__field(	unsigned long,	rip		)
-	),
+		__field(	u32,		inj_info	)
+		__field(	u32,		inj_info_err	)
+		__field(	bool,		guest_mode	)
+		__field(	bool,		req_imm_exit	)
+		),
 
 	TP_fast_assign(
 		__entry->vcpu_id        = vcpu->vcpu_id;
 		__entry->rip		= kvm_rip_read(vcpu);
+
+		static_call(kvm_x86_get_entry_info)(vcpu,
+					  &__entry->inj_info,
+					  &__entry->inj_info_err);
+
+		__entry->req_imm_exit   = vcpu->arch.req_immediate_exit;
+		__entry->guest_mode = is_guest_mode(vcpu);
 	),
 
-	TP_printk("vcpu %u, rip 0x%lx", __entry->vcpu_id, __entry->rip)
+	TP_printk("vcpu %u, rip 0x%lx inj 0x%08x inj_error_code 0x%08x%s%s",
+			__entry->vcpu_id, __entry->rip,
+			__entry->inj_info, __entry->inj_info_err,
+			__entry->req_imm_exit ? " [imm exit]" : "",
+			__entry->guest_mode ? " [guest]" : "")
 );
 
 /*
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index eb7e42235e8811..9dd13f52d4999c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6156,6 +6156,17 @@  static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
 	}
 }
 
+static void vmx_get_entry_info(struct kvm_vcpu *vcpu,
+			      u32 *inj_info,
+			      u32 *inj_info_error_code)
+{
+	*inj_info = vmcs_read32(VM_ENTRY_INTR_INFO_FIELD);
+	if (is_exception_with_error_code(*inj_info))
+		*inj_info_error_code = vmcs_read32(VM_ENTRY_EXCEPTION_ERROR_CODE);
+	else
+		*inj_info_error_code = 0;
+}
+
 static void vmx_destroy_pml_buffer(struct vcpu_vmx *vmx)
 {
 	if (vmx->pml_pg) {
@@ -8297,6 +8308,7 @@  static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.get_mt_mask = vmx_get_mt_mask,
 
 	.get_exit_info = vmx_get_exit_info,
+	.get_entry_info = vmx_get_entry_info,
 
 	.vcpu_after_set_cpuid = vmx_vcpu_after_set_cpuid,