KVM: nSVM: trap #DB and #BP to userspace if guest debugging is on

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 90a1ca9..adab5b1 100644 (file)
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -608,6 +608,11 @@ static int nested_svm_intercept_db(struct vcpu_svm *svm)
 {
        unsigned long dr6;
 
+       /* Always catch it and pass it to userspace if debugging.  */
+       if (svm->vcpu.guest_debug &
+           (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
+               return NESTED_EXIT_HOST;
+
        /* if we're not singlestepping, it's not ours */
        if (!svm->nmi_singlestep)
                return NESTED_EXIT_DONE;
@@ -682,6 +687,9 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
                if (svm->nested.intercept_exceptions & excp_bits) {
                        if (exit_code == SVM_EXIT_EXCP_BASE + DB_VECTOR)
                                vmexit = nested_svm_intercept_db(svm);
+                       else if (exit_code == SVM_EXIT_EXCP_BASE + BP_VECTOR &&
+                                svm->vcpu.guest_debug & KVM_GUESTDBG_USE_SW_BP)
+                               vmexit = NESTED_EXIT_HOST;
                        else
                                vmexit = NESTED_EXIT_DONE;
                }