[PATCH v6 2/4] KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info

From: David Edmondson
Date: Mon Sep 20 2021 - 06:39:03 EST


Extend the get_exit_info static call to provide the reason for the VM
exit. Modify relevant trace points to use this rather than extracting
the reason in the caller.

Signed-off-by: David Edmondson <david.edmondson@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 7 ++++---
arch/x86/kvm/svm/svm.c | 8 +++++---
arch/x86/kvm/trace.h | 9 +++++----
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 6 ++++--
5 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f8f48a7ec577..d22bbeb48f66 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1405,10 +1405,11 @@ struct kvm_x86_ops {
void (*write_tsc_multiplier)(struct kvm_vcpu *vcpu, u64 multiplier);

/*
- * Retrieve somewhat arbitrary exit information. Intended to be used
- * only from within tracepoints to avoid VMREADs when tracing is off.
+ * Retrieve somewhat arbitrary exit information. Intended to
+ * be used only from within tracepoints or error paths.
*/
- void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2,
+ void (*get_exit_info)(struct kvm_vcpu *vcpu, u32 *reason,
+ u64 *info1, u64 *info2,
u32 *exit_int_info, u32 *exit_int_info_err_code);

int (*check_intercept)(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 05e8d4d27969..a902a767f722 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3272,11 +3272,13 @@ int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
return svm_exit_handlers[exit_code](vcpu);
}

-static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2,
+static void svm_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
+ u64 *info1, u64 *info2,
u32 *intr_info, u32 *error_code)
{
struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control;

+ *reason = control->exit_code;
*info1 = control->exit_info_1;
*info2 = control->exit_info_2;
*intr_info = control->exit_int_info;
@@ -3293,7 +3295,7 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
struct kvm_run *kvm_run = vcpu->run;
u32 exit_code = svm->vmcb->control.exit_code;

- trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM);
+ trace_kvm_exit(vcpu, KVM_ISA_SVM);

/* SEV-ES guests must use the CR write traps to track CR registers. */
if (!sev_es_guest(vcpu->kvm)) {
@@ -3306,7 +3308,7 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
if (is_guest_mode(vcpu)) {
int vmexit;

- trace_kvm_nested_vmexit(exit_code, vcpu, KVM_ISA_SVM);
+ trace_kvm_nested_vmexit(vcpu, KVM_ISA_SVM);

vmexit = nested_svm_exit_special(svm);

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 03ebe368333e..953b0fcb21ee 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -288,8 +288,8 @@ TRACE_EVENT(kvm_apic,

#define TRACE_EVENT_KVM_EXIT(name) \
TRACE_EVENT(name, \
- TP_PROTO(unsigned int exit_reason, struct kvm_vcpu *vcpu, u32 isa), \
- TP_ARGS(exit_reason, vcpu, isa), \
+ TP_PROTO(struct kvm_vcpu *vcpu, u32 isa), \
+ TP_ARGS(vcpu, isa), \
\
TP_STRUCT__entry( \
__field( unsigned int, exit_reason ) \
@@ -303,11 +303,12 @@ TRACE_EVENT(name, \
), \
\
TP_fast_assign( \
- __entry->exit_reason = exit_reason; \
__entry->guest_rip = kvm_rip_read(vcpu); \
__entry->isa = isa; \
__entry->vcpu_id = vcpu->vcpu_id; \
- static_call(kvm_x86_get_exit_info)(vcpu, &__entry->info1, \
+ static_call(kvm_x86_get_exit_info)(vcpu, \
+ &__entry->exit_reason, \
+ &__entry->info1, \
&__entry->info2, \
&__entry->intr_info, \
&__entry->error_code); \
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index ccb03d69546c..43ea97b3f8e6 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6059,7 +6059,7 @@ bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu)
goto reflect_vmexit;
}

- trace_kvm_nested_vmexit(exit_reason.full, vcpu, KVM_ISA_VMX);
+ trace_kvm_nested_vmexit(vcpu, KVM_ISA_VMX);

/* If L0 (KVM) wants the exit, it trumps L1's desires. */
if (nested_vmx_l0_wants_exit(vcpu, exit_reason))
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0c2c0d5ae873..99f8f7c4a510 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5628,11 +5628,13 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
static const int kvm_vmx_max_exit_handlers =
ARRAY_SIZE(kvm_vmx_exit_handlers);

-static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2,
+static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
+ u64 *info1, u64 *info2,
u32 *intr_info, u32 *error_code)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);

+ *reason = vmx->exit_reason.full;
*info1 = vmx_get_exit_qual(vcpu);
if (!(vmx->exit_reason.failed_vmentry)) {
*info2 = vmx->idt_vectoring_info;
@@ -6769,7 +6771,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (likely(!vmx->exit_reason.failed_vmentry))
vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);

- trace_kvm_exit(vmx->exit_reason.full, vcpu, KVM_ISA_VMX);
+ trace_kvm_exit(vcpu, KVM_ISA_VMX);

if (unlikely(vmx->exit_reason.failed_vmentry))
return EXIT_FASTPATH_NONE;
--
2.33.0