[PATCH v5 1/3] KVM: x86: add more information to the kvm_entry tracepoint

From: Maxim Levitsky
Date: Tue Sep 10 2024 - 16:04:39 EST


Add VMX/SVM specific interrupt injection info to vm entry tracepoint.
Also add a flag showing that immediate vm exit is set to happen after
the entry.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
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 | 17 ++++++++++++++---
arch/x86/kvm/vmx/main.c | 1 +
arch/x86/kvm/vmx/vmx.c | 11 +++++++++++
arch/x86/kvm/vmx/x86_ops.h | 4 ++++
7 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 03b7e13f15bbd..af5c4d55d47bc 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_OPTIONAL(update_cpu_dirty_logging)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 52443ccda320f..8118f75a8a35d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1756,13 +1756,16 @@ 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 9a0506ef87dfb..485f3c2826312 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3525,6 +3525,22 @@ 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);
@@ -5057,6 +5073,7 @@ 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 d3aeffd6ae753..b4c014b1aa9a1 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -22,16 +22,27 @@ TRACE_EVENT(kvm_entry,
__field( unsigned int, vcpu_id )
__field( unsigned long, rip )
__field( bool, immediate_exit )
+ __field( u32, inj_info )
+ __field( u32, inj_info_err )
+ __field( bool, guest_mode )
),

TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->rip = kvm_rip_read(vcpu);
- __entry->immediate_exit = force_immediate_exit;
+ __entry->immediate_exit = force_immediate_exit;
+ __entry->guest_mode = is_guest_mode(vcpu);
+
+ static_call(kvm_x86_get_entry_info)(vcpu,
+ &__entry->inj_info,
+ &__entry->inj_info_err);
),

- TP_printk("vcpu %u, rip 0x%lx%s", __entry->vcpu_id, __entry->rip,
- __entry->immediate_exit ? "[immediate exit]" : "")
+ 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->immediate_exit ? "[immediate exit]" : "",
+ __entry->guest_mode ? "[guest]" : "")
);

/*
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 7e2e78a142574..769a7ca06f59b 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -108,6 +108,7 @@ struct kvm_x86_ops vt_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,

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 89682832dded7..af18174cc4a20 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6180,6 +6180,17 @@ void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
}
}

+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) {
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index b6a7cfc6ae317..124425997ec15 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -104,8 +104,12 @@ void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
int vmx_set_identity_map_addr(struct kvm *kvm, u64 ident_addr);
u8 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio);
+
void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
u64 *info1, u64 *info2, u32 *intr_info, u32 *error_code);
+void vmx_get_entry_info(struct kvm_vcpu *vcpu, u32 *inj_info,
+ u32 *inj_info_error_code);
+
u64 vmx_get_l2_tsc_offset(struct kvm_vcpu *vcpu);
u64 vmx_get_l2_tsc_multiplier(struct kvm_vcpu *vcpu);
void vmx_write_tsc_offset(struct kvm_vcpu *vcpu);
--
2.26.3