return;
switch (nr) {
+ case DB_VECTOR:
+ /*
+ * "Certain debug exceptions may clear bit 0-3. The
+ * remaining contents of the DR6 register are never
+ * cleared by the processor".
+ */
+ vcpu->arch.dr6 &= ~DR_TRAP_BITS;
+ /*
+ * DR6.RTM is set by all #DB exceptions that don't clear it.
+ */
+ vcpu->arch.dr6 |= DR6_RTM;
+ vcpu->arch.dr6 |= payload;
+ /*
+ * Bit 16 should be set in the payload whenever the #DB
+ * exception should clear DR6.RTM. This makes the payload
+ * compatible with the pending debug exceptions under VMX.
+ * Though not currently documented in the SDM, this also
+ * makes the payload compatible with the exit qualification
+ * for #DB exceptions under VMX.
+ */
+ vcpu->arch.dr6 ^= payload & DR6_RTM;
+ break;
case PF_VECTOR:
vcpu->arch.cr2 = payload;
break;
/*
* In guest mode, payload delivery should be deferred,
* so that the L1 hypervisor can intercept #PF before
- * CR2 is modified. However, for ABI compatibility
- * with KVM_GET_VCPU_EVENTS and KVM_SET_VCPU_EVENTS,
- * we can't delay payload delivery unless userspace
- * has enabled this functionality via the per-VM
- * capability, KVM_CAP_EXCEPTION_PAYLOAD.
+ * CR2 is modified (or intercept #DB before DR6 is
+ * modified under nVMX). However, for ABI
+ * compatibility with KVM_GET_VCPU_EVENTS and
+ * KVM_SET_VCPU_EVENTS, we can't delay payload
+ * delivery unless userspace has enabled this
+ * functionality via the per-VM capability,
+ * KVM_CAP_EXCEPTION_PAYLOAD.
*/
if (!vcpu->kvm->arch.exception_payload_enabled ||
!is_guest_mode(vcpu))
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception);
+static void kvm_queue_exception_p(struct kvm_vcpu *vcpu, unsigned nr,
+ unsigned long payload)
+{
+ kvm_multiple_exception(vcpu, nr, false, 0, true, payload, false);
+}
+
static void kvm_queue_exception_e_p(struct kvm_vcpu *vcpu, unsigned nr,
u32 error_code, unsigned long payload)
{
kvm_run->exit_reason = KVM_EXIT_DEBUG;
*r = EMULATE_USER_EXIT;
} else {
- /*
- * "Certain debug exceptions may clear bit 0-3. The
- * remaining contents of the DR6 register are never
- * cleared by the processor".
- */
- vcpu->arch.dr6 &= ~15;
- vcpu->arch.dr6 |= DR6_BS | DR6_RTM;
- kvm_queue_exception(vcpu, DB_VECTOR);
+ kvm_queue_exception_p(vcpu, DB_VECTOR, DR6_BS);
}
}
__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
X86_EFLAGS_RF);
- if (vcpu->arch.exception.nr == DB_VECTOR &&
- (vcpu->arch.dr7 & DR7_GD)) {
- vcpu->arch.dr7 &= ~DR7_GD;
- kvm_update_dr7(vcpu);
+ if (vcpu->arch.exception.nr == DB_VECTOR) {
+ /*
+ * This code assumes that nSVM doesn't use
+ * check_nested_events(). If it does, the
+ * DR6/DR7 changes should happen before L1
+ * gets a #VMEXIT for an intercepted #DB in
+ * L2. (Under VMX, on the other hand, the
+ * DR6/DR7 changes should not happen in the
+ * event of a VM-exit to L1 for an intercepted
+ * #DB in L2.)
+ */
+ kvm_deliver_exception_payload(vcpu);
+ if (vcpu->arch.dr7 & DR7_GD) {
+ vcpu->arch.dr7 &= ~DR7_GD;
+ kvm_update_dr7(vcpu);
+ }
}
kvm_x86_ops->queue_exception(vcpu);