KVM: nSVM: Trace VM-Enter consistency check failures

Use trace_kvm_nested_vmenter_failed() and its macro magic to trace
consistency check failures on nested VMRUN.  Tracing such failures by
running the buggy VMM as a KVM guest is often the only way to get a
precise explanation of why VMRUN failed.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210204000117.3303214-13-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 9960b6746ec54ddf8b0387a2c42c69d79ef57dc8..6936d8a02141917e2019ab748aea6aa7f0113fc6 100644 (file)
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -29,6 +29,8 @@
 #include "lapic.h"
 #include "svm.h"
 
+#define CC KVM_NESTED_VMENTER_CONSISTENCY_CHECK
+
 static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
                                       struct x86_exception *fault)
 {
@@ -233,14 +235,13 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
 
 static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
 {
-       if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
+       if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN)))
                return false;
 
-       if (control->asid == 0)
+       if (CC(control->asid == 0))
                return false;
 
-       if ((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) &&
-           !npt_enabled)
+       if (CC((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) && !npt_enabled))
                return false;
 
        return true;
@@ -257,32 +258,36 @@ static bool nested_vmcb_check_cr3_cr4(struct vcpu_svm *svm,
         * CR0.PG && EFER.LME.
         */
        if ((save->efer & EFER_LME) && (save->cr0 & X86_CR0_PG)) {
-               if (!(save->cr4 & X86_CR4_PAE) || !(save->cr0 & X86_CR0_PE) ||
-                   kvm_vcpu_is_illegal_gpa(vcpu, save->cr3))
+               if (CC(!(save->cr4 & X86_CR4_PAE)) ||
+                   CC(!(save->cr0 & X86_CR0_PE)) ||
+                   CC(kvm_vcpu_is_illegal_gpa(vcpu, save->cr3)))
                        return false;
        }
 
-       return kvm_is_valid_cr4(&svm->vcpu, save->cr4);
+       if (CC(!kvm_is_valid_cr4(vcpu, save->cr4)))
+               return false;
+
+       return true;
 }
 
 /* Common checks that apply to both L1 and L2 state.  */
 static bool nested_vmcb_valid_sregs(struct vcpu_svm *svm,
                                    struct vmcb_save_area *save)
 {
-       if (!(save->efer & EFER_SVME))
+       if (CC(!(save->efer & EFER_SVME)))
                return false;
 
-       if (((save->cr0 & X86_CR0_CD) == 0 && (save->cr0 & X86_CR0_NW)) ||
-           (save->cr0 & ~0xffffffffULL))
+       if (CC((save->cr0 & X86_CR0_CD) == 0 && (save->cr0 & X86_CR0_NW)) ||
+           CC(save->cr0 & ~0xffffffffULL))
                return false;
 
-       if (!kvm_dr6_valid(save->dr6) || !kvm_dr7_valid(save->dr7))
+       if (CC(!kvm_dr6_valid(save->dr6)) || CC(!kvm_dr7_valid(save->dr7)))
                return false;
 
        if (!nested_vmcb_check_cr3_cr4(svm, save))
                return false;
 
-       if (!kvm_valid_efer(&svm->vcpu, save->efer))
+       if (CC(!kvm_valid_efer(&svm->vcpu, save->efer)))
                return false;
 
        return true;
@@ -384,12 +389,12 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm)
 static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
                               bool nested_npt)
 {
-       if (kvm_vcpu_is_illegal_gpa(vcpu, cr3))
+       if (CC(kvm_vcpu_is_illegal_gpa(vcpu, cr3)))
                return -EINVAL;
 
        if (!nested_npt && is_pae_paging(vcpu) &&
            (cr3 != kvm_read_cr3(vcpu) || pdptrs_changed(vcpu))) {
-               if (!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
+               if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)))
                        return -EINVAL;
        }