[PATCH v2] kvm: x86: move tracepoints outside extended quiescent state

From: Paolo Bonzini
Date: Thu Dec 10 2015 - 13:16:31 EST


Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a
lockdep splat.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm.c | 4 ++--
arch/x86/kvm/vmx.c | 3 ++-
arch/x86/kvm/x86.c | 4 ++--
3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 83a1c643f9a5..899c40f826dd 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3422,6 +3422,8 @@ static int handle_exit(struct kvm_vcpu *vcpu)
struct kvm_run *kvm_run = vcpu->run;
u32 exit_code = svm->vmcb->control.exit_code;

+ trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM);
+
if (!is_cr_intercept(svm, INTERCEPT_CR0_WRITE))
vcpu->arch.cr0 = svm->vmcb->save.cr0;
if (npt_enabled)
@@ -3892,8 +3894,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp;
vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;

- trace_kvm_exit(svm->vmcb->control.exit_code, vcpu, KVM_ISA_SVM);
-
if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
kvm_before_handle_nmi(&svm->vcpu);

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index af823a388c19..6b5605607849 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8042,6 +8042,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
u32 exit_reason = vmx->exit_reason;
u32 vectoring_info = vmx->idt_vectoring_info;

+ trace_kvm_exit(exit_reason, vcpu, KVM_ISA_VMX);
+
/*
* Flush logged GPAs PML buffer, this will make dirty_bitmap more
* updated. Another good is, in kvm_vm_ioctl_get_dirty_log, before
@@ -8668,7 +8670,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->loaded_vmcs->launched = 1;

vmx->exit_reason = vmcs_read32(VM_EXIT_REASON);
- trace_kvm_exit(vmx->exit_reason, vcpu, KVM_ISA_VMX);

/*
* the KVM_REQ_EVENT optimization bit is only on for one entry, and if
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eed32283d22c..b84ba4b17757 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6515,6 +6515,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (req_immediate_exit)
smp_send_reschedule(vcpu->cpu);

+ trace_kvm_entry(vcpu->vcpu_id);
+ wait_lapic_expire(vcpu);
__kvm_guest_enter();

if (unlikely(vcpu->arch.switch_db_regs)) {
@@ -6527,8 +6529,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
}

- trace_kvm_entry(vcpu->vcpu_id);
- wait_lapic_expire(vcpu);
kvm_x86_ops->run(vcpu);

/*
--
1.8.3.1

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