-/* DB exceptions for our internal use must not cause vmexit */
-static int nested_svm_intercept_db(struct vcpu_svm *svm)
-{
- unsigned long dr6 = svm->vmcb->save.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)
- goto reflected_db;
-
- /* if it's not a singlestep exception, it's not ours */
- if (!(dr6 & DR6_BS))
- goto reflected_db;
-
- /* if the guest is singlestepping, it should get the vmexit */
- if (svm->nmi_singlestep_guest_rflags & X86_EFLAGS_TF) {
- disable_nmi_singlestep(svm);
- goto reflected_db;
- }
-
- /* it's ours, the nested hypervisor must not see this one */
- return NESTED_EXIT_HOST;
-
-reflected_db:
- /*
- * Synchronize guest DR6 here just like in kvm_deliver_exception_payload;
- * it will be moved into the nested VMCB by nested_svm_vmexit. Once
- * exceptions will be moved to svm_check_nested_events, all this stuff
- * will just go away and we could just return NESTED_EXIT_HOST
- * unconditionally. db_interception will queue the exception, which
- * will be processed by svm_check_nested_events if a nested vmexit is
- * required, and we will just use kvm_deliver_exception_payload to copy
- * the payload to DR6 before vmexit.
- */
- WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT);
- svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM);
- svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1;
- return NESTED_EXIT_DONE;
-}
-