SVM: return EIO to vmd to stop the guest when it HLTs with interrupts

disabled (no NMI support yet)

diff --git a/sys/arch/amd64/amd64/vmm.c b/sys/arch/amd64/amd64/vmm.c
index 0b58bf8..d1184e5 100644 (file)
--- a/sys/arch/amd64/amd64/vmm.c
+++ b/sys/arch/amd64/amd64/vmm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vmm.c,v 1.150 2017/05/30 19:13:20 mlarkin Exp $       */
+/*     $OpenBSD: vmm.c,v 1.151 2017/05/30 19:31:28 mlarkin Exp $       */
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
  *
@@ -3967,13 +3967,30 @@ vmx_handle_intr(struct vcpu *vcpu)
  * svm_handle_hlt
  *
  * Handle HLT exits
+ *
+ * Parameters
+ *  vcpu: The VCPU that executed the HLT instruction
+ *
+ * Return Values:
+ *  EIO: The guest halted with interrupts disabled
+ *  EAGAIN: Normal return to vmd - vmd should halt scheduling this VCPU
+ *   until a virtual interrupt is ready to inject
  */
 int
 svm_handle_hlt(struct vcpu *vcpu)
 {
+       struct vmcb *vmcb = (struct vmcb *)vcpu->vc_control_va;
+       uint64_t rflags = vmcb->v_rflags;
+
        /* All HLT insns are 1 byte */
        vcpu->vc_gueststate.vg_rip += 1;
 
+       if (!(rflags & PSL_I)) {
+               DPRINTF("%s: guest halted with interrupts disabled\n",
+                   __func__);
+               return (EIO);
+       }
+
        return (EAGAIN);
 }
 
@@ -4012,7 +4029,8 @@ vmx_handle_hlt(struct vcpu *vcpu)
        KASSERT(insn_length == 1);
 
        if (!(rflags & PSL_I)) {
-               DPRINTF("%s: guest halted with interrupts disabled\n", __func__);
+               DPRINTF("%s: guest halted with interrupts disabled\n",
+                   __func__);
                return (EIO);
        }