3605 Xen HVM hangs during boot if apix is enabled

*** 112,122 ****
  static void apix_intx_clear_mask(int irqno);
  static int apix_intx_get_shared(int irqno);
  static void apix_intx_set_shared(int irqno, int delta);
  static apix_vector_t *apix_intx_xlate_vector(dev_info_t *, int,
      struct intrspec *);
! static int apix_intx_alloc_vector(dev_info_t *, int, struct intrspec *);
  
  extern int apic_clkinit(int);
  
  /* IRM initialization for APIX PSM module */
  extern void apix_irm_init(void);
--- 112,123 ----
  static void apix_intx_clear_mask(int irqno);
  static int apix_intx_get_shared(int irqno);
  static void apix_intx_set_shared(int irqno, int delta);
  static apix_vector_t *apix_intx_xlate_vector(dev_info_t *, int,
      struct intrspec *);
! static int apix_intx_alloc_vector(dev_info_t *, ddi_intr_handle_impl_t *,
!     struct intrspec *);
  
  extern int apic_clkinit(int);
  
  /* IRM initialization for APIX PSM module */
  extern void apix_irm_init(void);
*** 259,277 ****
          int rval;
  
          if (apix_enable == 0)
                  return (PSM_FAILURE);
  
-         /*
-          * FIXME Temporarily disable apix module on Xen HVM platform due to
-          * known hang during boot (see #3605).
-          *
-          * Please remove when/if the issue is resolved.
-          */
-         if (get_hwenv() == HW_XEN_HVM)
-                 return (PSM_FAILURE);
- 
          /* check for hw features if specified  */
          if (apix_hw_chk_enable) {
                  /* check if x2APIC mode is supported */
                  if ((apix_supported_hw & APIX_SUPPORT_X2APIC) ==
                      APIX_SUPPORT_X2APIC) {
--- 260,269 ----
*** 1182,1193 ****
                          /* allocate or share vector for fixed */
                          if ((ihdl_plat_t *)hdlp->ih_private == NULL) {
                                  return (PSM_FAILURE);
                          }
                          ispec = ((ihdl_plat_t *)hdlp->ih_private)->ip_ispecp;
!                         *result = apix_intx_alloc_vector(dip, hdlp->ih_inum,
!                             ispec);
                          break;
                  default:
                          return (PSM_FAILURE);
                  }
                  break;
--- 1174,1184 ----
                          /* allocate or share vector for fixed */
                          if ((ihdl_plat_t *)hdlp->ih_private == NULL) {
                                  return (PSM_FAILURE);
                          }
                          ispec = ((ihdl_plat_t *)hdlp->ih_private)->ip_ispecp;
!                         *result = apix_intx_alloc_vector(dip, hdlp, ispec);
                          break;
                  default:
                          return (PSM_FAILURE);
                  }
                  break;
*** 2521,2541 ****
          mutex_exit(&airq_mutex);
          return (newirq);
  }
  
  static int
! apix_intx_alloc_vector(dev_info_t *dip, int inum, struct intrspec *ispec)
  {
          int irqno;
          apix_vector_t *vecp;
  
!         if ((irqno = apix_intx_xlate_irq(dip, inum, ispec)) == -1)
                  return (0);
  
!         if ((vecp = apix_alloc_intx(dip, inum, irqno)) == NULL)
                  return (0);
  
          DDI_INTR_IMPLDBG((CE_CONT, "apix_intx_alloc_vector: dip=0x%p name=%s "
              "irqno=0x%x cpuid=%d vector=0x%x\n",
              (void *)dip, ddi_driver_name(dip), irqno,
              vecp->v_cpuid, vecp->v_vector));
  
--- 2512,2535 ----
          mutex_exit(&airq_mutex);
          return (newirq);
  }
  
  static int
! apix_intx_alloc_vector(dev_info_t *dip, ddi_intr_handle_impl_t *hdlp,
!     struct intrspec *ispec)
  {
          int irqno;
          apix_vector_t *vecp;
  
!         if ((irqno = apix_intx_xlate_irq(dip, hdlp->ih_inum, ispec)) == -1)
                  return (0);
  
!         if ((vecp = apix_alloc_intx(dip, hdlp->ih_inum, irqno)) == NULL)
                  return (0);
  
+         hdlp->ih_irq = irqno;
+ 
          DDI_INTR_IMPLDBG((CE_CONT, "apix_intx_alloc_vector: dip=0x%p name=%s "
              "irqno=0x%x cpuid=%d vector=0x%x\n",
              (void *)dip, ddi_driver_name(dip), irqno,
              vecp->v_cpuid, vecp->v_vector));