Palacios Public Git Repository

To checkout Palacios execute

  git clone http://v3vee.org/palacios/palacios.web/palacios.git
This will give you the master branch. You probably want the devel branch or one of the release branches. To switch to the devel branch, simply execute
  cd palacios
  git checkout --track -b devel origin/devel
The other branches are similar.


Added correct physical delivery check for apic
[palacios.git] / palacios / src / devices / apic.c
index 77f727b..427ec79 100644 (file)
@@ -11,7 +11,8 @@
  * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
  * All rights reserved.
  *
- * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ * Authors: Jack Lange <jarusl@cs.northwestern.edu>
+ *          Peter Dinda <pdinda@northwestern.edu> (SMP)
  *
  * This is free software.  You are permitted to use,
  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
 #include <devices/apic_regs.h>
 #include <palacios/vmm.h>
 #include <palacios/vmm_msr.h>
+#include <palacios/vmm_sprintf.h>
+#include <palacios/vm_guest.h>
+#include <palacios/vmm_types.h>
 
 
-#ifndef DEBUG_APIC
+
+
+#ifndef CONFIG_DEBUG_APIC
 #undef PrintDebug
 #define PrintDebug(fmt, args...)
 #endif
 
 
+#ifdef CONFIG_DEBUG_APIC
+static char * shorthand_str[] = { 
+    "(no shorthand)",
+    "(self)",
+    "(all)",
+    "(all-but-me)",
+};
+
+static char * deliverymode_str[] = { 
+    "(fixed)",
+    "(lowest priority)",
+    "(SMI)",
+    "(reserved)",
+    "(NMI)",
+    "(INIT)",
+    "(Start Up)",
+    "(ExtInt)",
+};
+#endif
+
+// Temporary removal of locking
+#define v3_lock(p) p=p
+#define v3_unlock(p) p=p
+
+
 typedef enum { APIC_TMR_INT, APIC_THERM_INT, APIC_PERF_INT, 
               APIC_LINT0_INT, APIC_LINT1_INT, APIC_ERR_INT } apic_irq_type_t;
 
 #define APIC_FIXED_DELIVERY  0x0
+#define APIC_LOWEST_DELIVERY 0x1
 #define APIC_SMI_DELIVERY    0x2
+#define APIC_RES1_DELIVERY   0x3
 #define APIC_NMI_DELIVERY    0x4
 #define APIC_INIT_DELIVERY   0x5
+#define APIC_SIPI_DELIVERY   0x6
 #define APIC_EXTINT_DELIVERY 0x7
 
+#define APIC_SHORTHAND_NONE        0x0
+#define APIC_SHORTHAND_SELF        0x1
+#define APIC_SHORTHAND_ALL         0x2
+#define APIC_SHORTHAND_ALL_BUT_ME  0x3
+
+#define APIC_DEST_PHYSICAL    0x0
+#define APIC_DEST_LOGICAL     0x1
 
-#define BASE_ADDR_MSR 0x0000001B
+
+#define BASE_ADDR_MSR     0x0000001B
 #define DEFAULT_BASE_ADDR 0xfee00000
 
 #define APIC_ID_OFFSET                    0x020
@@ -113,863 +155,1748 @@ typedef enum { APIC_TMR_INT, APIC_THERM_INT, APIC_PERF_INT,
 #define EXT_INT_LOC_VEC_TBL_OFFSET2       0x520   // 0x500 - 0x530
 #define EXT_INT_LOC_VEC_TBL_OFFSET3       0x530   // 0x500 - 0x530
 
-
-
 struct apic_msr {
-  union {
-    uint64_t val;
-    struct {
-      uchar_t rsvd;
-      uint_t bootstrap_cpu : 1;
-      uint_t rsvd2         : 2;
-      uint_t apic_enable   : 1;
-      ullong_t base_addr   : 40;
-      uint_t rsvd3         : 12;
+    union {
+       uint64_t value;
+       struct {
+           uint8_t rsvd;
+           uint8_t bootstrap_cpu : 1;
+           uint8_t rsvd2         : 2;
+           uint8_t apic_enable   : 1;
+           uint64_t base_addr    : 40;
+           uint32_t rsvd3        : 12;
+       } __attribute__((packed));
     } __attribute__((packed));
-  } __attribute__((packed));
 } __attribute__((packed));
 
 
 
+typedef enum {INIT_ST, 
+             SIPI, 
+             STARTED} ipi_state_t; 
+
+struct apic_dev_state;
 
 struct apic_state {
-  addr_t base_addr;
-
-  /* MSRs */
-  v3_msr_t base_addr_msr;
-
-
-  /* memory map registers */
-
-  struct lapic_id_reg lapic_id;
-  struct apic_ver_reg apic_ver;
-  struct ext_apic_ctrl_reg ext_apic_ctrl;
-  struct local_vec_tbl_reg local_vec_tbl;
-  struct tmr_vec_tbl_reg tmr_vec_tbl;
-  struct tmr_div_cfg_reg tmr_div_cfg;
-  struct lint_vec_tbl_reg lint0_vec_tbl;
-  struct lint_vec_tbl_reg lint1_vec_tbl;
-  struct perf_ctr_loc_vec_tbl_reg perf_ctr_loc_vec_tbl;
-  struct therm_loc_vec_tbl_reg therm_loc_vec_tbl;
-  struct err_vec_tbl_reg err_vec_tbl;
-  struct err_status_reg err_status;
-  struct spurious_int_reg spurious_int;
-  struct int_cmd_reg int_cmd;
-  struct log_dst_reg log_dst;
-  struct dst_fmt_reg dst_fmt;
-  struct arb_prio_reg arb_prio;
-  struct task_prio_reg task_prio;
-  struct proc_prio_reg proc_prio;
-  struct ext_apic_feature_reg ext_apic_feature;
-  struct spec_eoi_reg spec_eoi;
+    addr_t base_addr;
+
+    /* MSRs */
+    struct apic_msr base_addr_msr;
+
+
+    /* memory map registers */
+
+    struct lapic_id_reg lapic_id;
+    struct apic_ver_reg apic_ver;
+    struct ext_apic_ctrl_reg ext_apic_ctrl;
+    struct local_vec_tbl_reg local_vec_tbl;
+    struct tmr_vec_tbl_reg tmr_vec_tbl;
+    struct tmr_div_cfg_reg tmr_div_cfg;
+    struct lint_vec_tbl_reg lint0_vec_tbl;
+    struct lint_vec_tbl_reg lint1_vec_tbl;
+    struct perf_ctr_loc_vec_tbl_reg perf_ctr_loc_vec_tbl;
+    struct therm_loc_vec_tbl_reg therm_loc_vec_tbl;
+    struct err_vec_tbl_reg err_vec_tbl;
+    struct err_status_reg err_status;
+    struct spurious_int_reg spurious_int;
+    struct int_cmd_reg int_cmd;
+    struct log_dst_reg log_dst;
+    struct dst_fmt_reg dst_fmt;
+    struct arb_prio_reg arb_prio;
+    struct task_prio_reg task_prio;
+    struct proc_prio_reg proc_prio;
+    struct ext_apic_feature_reg ext_apic_feature;
+    struct spec_eoi_reg spec_eoi;
   
 
-  uint32_t tmr_cur_cnt;
-  uint32_t tmr_init_cnt;
+    uint32_t tmr_cur_cnt;
+    uint32_t tmr_init_cnt;
 
 
+    struct local_vec_tbl_reg ext_intr_vec_tbl[4];
 
-  uint32_t rem_rd_data;
+    uint32_t rem_rd_data;
 
 
-  uchar_t int_req_reg[32];
-  uchar_t int_svc_reg[32];
-  uchar_t int_en_reg[32];
-  uchar_t trig_mode_reg[32];
-  
-  uint32_t eoi;
+    ipi_state_t ipi_state;
+
+    uint8_t int_req_reg[32];
+    uint8_t int_svc_reg[32];
+    uint8_t int_en_reg[32];
+    uint8_t trig_mode_reg[32];
+
+    struct guest_info * core;
+
+    void * controller_handle;
+
+    struct v3_timer * timer;
 
+    uint32_t eoi;
 
+    v3_lock_t  lock;
+
+    // debug
+    uint8_t in_icr;   
 };
 
 
-static void init_apic_state(struct apic_state * apic) {
-  apic->base_addr = DEFAULT_BASE_ADDR;
-  apic->base_addr_msr.value = 0x0000000000000900LL;
-  apic->base_addr_msr.value |= ((uint64_t)DEFAULT_BASE_ADDR); 
-
-  PrintDebug("Sizeof Interrupt Request Register %d, should be 32\n", 
-            (uint_t)sizeof(apic->int_req_reg));
-
-  memset(apic->int_req_reg, 0, sizeof(apic->int_req_reg));
-  memset(apic->int_svc_reg, 0, sizeof(apic->int_svc_reg));
-  memset(apic->int_en_reg, 0xff, sizeof(apic->int_en_reg));
-  memset(apic->trig_mode_reg, 0, sizeof(apic->trig_mode_reg));
-
-  apic->eoi = 0x00000000;
-  apic->rem_rd_data = 0x00000000;
-  apic->tmr_init_cnt = 0x00000000;
-  apic->tmr_cur_cnt = 0x00000000;
-
-  // TODO:
-  // We need to figure out what the APIC ID is....
-  apic->lapic_id.val = 0x00000000;
-
-  // The P6 has 6 LVT entries, so we set the value to (6-1)...
-  apic->apic_ver.val = 0x80050010;
-
-  apic->task_prio.val = 0x00000000;
-  apic->arb_prio.val = 0x00000000;
-  apic->proc_prio.val = 0x00000000;
-  apic->log_dst.val = 0x00000000;
-  apic->dst_fmt.val = 0xffffffff;
-  apic->spurious_int.val = 0x000000ff;
-  apic->err_status.val = 0x00000000;
-  apic->int_cmd.val = 0x0000000000000000LL;
-  apic->tmr_vec_tbl.val = 0x00010000;
-  apic->therm_loc_vec_tbl.val = 0x00010000;
-  apic->perf_ctr_loc_vec_tbl.val = 0x00010000;
-  apic->lint0_vec_tbl.val = 0x00010000;
-  apic->lint1_vec_tbl.val = 0x00010000;
-  apic->err_vec_tbl.val = 0x00010000;
-  apic->tmr_div_cfg.val = 0x00000000;
-  apic->ext_apic_feature.val = 0x00040007;
-  apic->ext_apic_ctrl.val = 0x00000000;
-  apic->spec_eoi.val = 0x00000000;
+
+
+struct apic_dev_state {
+    int num_apics;
+    //    v3_lock_t ipi_lock;   // acquired by route_ipi - only one IPI active at a time
+
+    struct apic_state apics[0];
+} __attribute__((packed));
+
+
+
+
+
+static int apic_read(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data);
+static int apic_write(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data);
+
+// No lcoking done
+static void init_apic_state(struct apic_state * apic, uint32_t id) {
+    apic->base_addr = DEFAULT_BASE_ADDR;
+
+    if (id == 0) { 
+       // boot processor, enabled
+       apic->base_addr_msr.value = 0x0000000000000900LL;
+    } else {
+       // ap processor, enabled
+       apic->base_addr_msr.value = 0x0000000000000800LL;
+    }
+
+    // same base address regardless of ap or main
+    apic->base_addr_msr.value |= ((uint64_t)DEFAULT_BASE_ADDR); 
+
+    PrintDebug("apic %u: (init_apic_state): msr=0x%llx\n",id, apic->base_addr_msr.value);
+
+    PrintDebug("apic %u: (init_apic_state): Sizeof Interrupt Request Register %d, should be 32\n",
+              id, (uint_t)sizeof(apic->int_req_reg));
+
+    memset(apic->int_req_reg, 0, sizeof(apic->int_req_reg));
+    memset(apic->int_svc_reg, 0, sizeof(apic->int_svc_reg));
+    memset(apic->int_en_reg, 0xff, sizeof(apic->int_en_reg));
+    memset(apic->trig_mode_reg, 0, sizeof(apic->trig_mode_reg));
+
+    apic->eoi = 0x00000000;
+    apic->rem_rd_data = 0x00000000;
+    apic->tmr_init_cnt = 0x00000000;
+    apic->tmr_cur_cnt = 0x00000000;
+
+    apic->lapic_id.val = id;
+    
+    apic->ipi_state = INIT_ST;
+
+    // The P6 has 6 LVT entries, so we set the value to (6-1)...
+    apic->apic_ver.val = 0x80050010;
+
+    apic->task_prio.val = 0x00000000;
+    apic->arb_prio.val = 0x00000000;
+    apic->proc_prio.val = 0x00000000;
+    apic->log_dst.val = 0x00000000;
+    apic->dst_fmt.val = 0xffffffff;
+    apic->spurious_int.val = 0x000000ff;
+    apic->err_status.val = 0x00000000;
+    apic->int_cmd.val = 0x0000000000000000LL;
+    apic->tmr_vec_tbl.val = 0x00010000;
+    apic->therm_loc_vec_tbl.val = 0x00010000;
+    apic->perf_ctr_loc_vec_tbl.val = 0x00010000;
+    apic->lint0_vec_tbl.val = 0x00010000;
+    apic->lint1_vec_tbl.val = 0x00010000;
+    apic->err_vec_tbl.val = 0x00010000;
+    apic->tmr_div_cfg.val = 0x00000000;
+    //apic->ext_apic_feature.val = 0x00000007;
+    apic->ext_apic_feature.val = 0x00040007;
+    apic->ext_apic_ctrl.val = 0x00000000;
+    apic->spec_eoi.val = 0x00000000;
+
+    v3_lock_init(&(apic->lock));
+
+    //debug
+    apic->in_icr=0;
 }
 
 
 
 
-static int read_apic_msr(uint_t msr, v3_msr_t * dst, void * priv_data) {
-  struct vm_device * dev = (struct vm_device *)priv_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  PrintError("READING APIC BASE ADDR: HI=%x LO=%x\n", apic->base_addr_msr.hi, apic->base_addr_msr.lo);
+// MSR handler - locks apic itself
+static int read_apic_msr(struct guest_info * core, uint_t msr, v3_msr_t * dst, void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)priv_data;
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]);
 
-  return -1;
+    PrintDebug("apic %u: core %u: MSR read\n", apic->lapic_id.val, core->cpu_id);
+    v3_lock(apic->lock);
+    dst->value = apic->base_addr;
+    v3_unlock(apic->lock);
+    return 0;
 }
 
+// MSR handler - locks apic itself
+static int write_apic_msr(struct guest_info * core, uint_t msr, v3_msr_t src, void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)priv_data;
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]);
+    struct v3_mem_region * old_reg = v3_get_mem_region(core->vm_info, core->cpu_id, apic->base_addr);
+
+
+    PrintDebug("apic %u: core %u: MSR write\n", apic->lapic_id.val, core->cpu_id);
 
-static int write_apic_msr(uint_t msr, v3_msr_t src, void * priv_data) {
-  //  struct vm_device * dev = (struct vm_device *)priv_data;
-  //  struct apic_state * apic = (struct apic_state *)dev->private_data;
+    if (old_reg == NULL) {
+       // uh oh...
+       PrintError("apic %u: core %u: APIC Base address region does not exit...\n",
+                  apic->lapic_id.val, core->cpu_id);
+       return -1;
+    }
+    
+    v3_lock(apic->lock);
+
+    v3_delete_mem_region(core->vm_info, old_reg);
 
-  PrintError("WRITING APIC BASE ADDR: HI=%x LO=%x\n", src.hi, src.lo);
+    apic->base_addr = src.value;
+
+    if (v3_hook_full_mem(core->vm_info, core->cpu_id, apic->base_addr, 
+                        apic->base_addr + PAGE_SIZE_4KB, 
+                        apic_read, apic_write, apic_dev) == -1) {
+       PrintError("apic %u: core %u: Could not hook new APIC Base address\n",
+                  apic->lapic_id.val, core->cpu_id);
+       v3_unlock(apic->lock);
+       return -1;
+    }
 
-  return -1;
+    v3_unlock(apic->lock);
+    return 0;
 }
 
 
 // irq_num is the bit offset into a 256 bit buffer...
-static int activate_apic_irq(struct apic_state * apic, uint32_t irq_num) {
-  int major_offset = (irq_num & ~0x00000007) >> 3;
-  int minor_offset = irq_num & 0x00000007;
-  uchar_t * req_location = apic->int_req_reg + major_offset;
-  uchar_t * en_location = apic->int_en_reg + major_offset;
-  uchar_t flag = 0x1 << minor_offset;
-
-  if (irq_num <= 15) {
-    PrintError("Attempting to raise an invalid interrupt: %d\n", irq_num);
-    return -1;
-  }
+// return values
+//    -1 = error
+//     0 = OK, no interrupt needed now
+//     1 = OK, interrupt needed now
+// the caller is expeced to have locked the apic
+static int activate_apic_irq_nolock(struct apic_state * apic, uint32_t irq_num) {
+    int major_offset = (irq_num & ~0x00000007) >> 3;
+    int minor_offset = irq_num & 0x00000007;
+    uint8_t * req_location = apic->int_req_reg + major_offset;
+    uint8_t * en_location = apic->int_en_reg + major_offset;
+    uint8_t flag = 0x1 << minor_offset;
+
+
+    if (irq_num <= 15 || irq_num>255) {
+       PrintError("apic %u: core %d: Attempting to raise an invalid interrupt: %d\n", 
+                  apic->lapic_id.val, apic->core->cpu_id, irq_num);
+       return -1;
+    }
 
-  PrintDebug("Raising APIC IRQ %d\n", irq_num);
 
-  if (*en_location & flag) {
-    *req_location |= flag;
-  } else {
-    PrintDebug("Interrupt  not enabled... %.2x\n", *en_location);
-    return 0;
-  }
+    PrintDebug("apic %u: core %d: Raising APIC IRQ %d\n", apic->lapic_id.val, apic->core->cpu_id, irq_num);
 
-  return 0;
-}
+    if (*req_location & flag) {
+       PrintDebug("Interrupt %d  coallescing\n", irq_num);
+       return 0;
+    }
 
+    if (*en_location & flag) {
+       *req_location |= flag;
 
+       if (apic->in_icr) { 
+           PrintError("apic %u: core %d: activate_apic_irq_nolock to deliver irq 0x%x when in_icr=1\n",  apic->lapic_id.val, apic->core->cpu_id, irq_num);
+           //      return 0;
+       }
 
-static int apic_do_eoi(struct apic_state * apic) {
-  int i = 0, j = 0;
+       return 1;
+    } else {
+       PrintDebug("apic %u: core %d: Interrupt  not enabled... %.2x\n", 
+                  apic->lapic_id.val, apic->core->cpu_id,*en_location);
+       return 0;
+    }
+
+}
 
-  // We iterate backwards to find the highest priority
-  for (i = 31; i >= 0; i--) {
-    uchar_t  * svc_major = apic->int_svc_reg + i;
+
+// Caller is expected to have locked the apic
+static int get_highest_isr(struct apic_state * apic) {
+    int i = 0, j = 0;
+
+    // We iterate backwards to find the highest priority
+    for (i = 31; i >= 0; i--) {
+       uint8_t  * svc_major = apic->int_svc_reg + i;
     
-    if ((*svc_major) & 0xff) {
-      for (j = 7; j >= 0; j--) {
-       uchar_t flag = 0x1 << j;
-       if ((*svc_major) & flag) {
-         *svc_major &= ~flag;
-         return 0;
+       if ((*svc_major) & 0xff) {
+           for (j = 7; j >= 0; j--) {
+               uint8_t flag = 0x1 << j;
+               if ((*svc_major) & flag) {
+                   return ((i * 8) + j);
+               }
+           }
        }
-      }
     }
-  }
 
-  return 0;
+    return -1;
 }
  
 
-static int activate_internal_irq(struct apic_state * apic, apic_irq_type_t int_type) {
-  uint32_t vec_num = 0;
-  uint32_t del_mode = 0;
-  int masked = 0;
-
-
-  switch (int_type) {
-  case APIC_TMR_INT:
-    vec_num = apic->tmr_vec_tbl.vec;
-    del_mode = APIC_FIXED_DELIVERY;
-    masked = apic->tmr_vec_tbl.mask;
-    break;
-  case APIC_THERM_INT:
-    vec_num = apic->therm_loc_vec_tbl.vec;
-    del_mode = apic->therm_loc_vec_tbl.msg_type;
-    masked = apic->therm_loc_vec_tbl.mask;
-    break;
-  case APIC_PERF_INT:
-    vec_num = apic->perf_ctr_loc_vec_tbl.vec;
-    del_mode = apic->perf_ctr_loc_vec_tbl.msg_type;
-    masked = apic->perf_ctr_loc_vec_tbl.mask;
-    break;
-  case APIC_LINT0_INT:
-    vec_num = apic->lint0_vec_tbl.vec;
-    del_mode = apic->lint0_vec_tbl.msg_type;
-    masked = apic->lint0_vec_tbl.mask;
-    break;
-  case APIC_LINT1_INT:
-    vec_num = apic->lint1_vec_tbl.vec;
-    del_mode = apic->lint1_vec_tbl.msg_type;
-    masked = apic->lint1_vec_tbl.mask;
-    break;
-  case APIC_ERR_INT:
-    vec_num = apic->err_vec_tbl.vec;
-    del_mode = APIC_FIXED_DELIVERY;
-    masked = apic->err_vec_tbl.mask;
-    break;
-  default:
-    PrintError("Invalid APIC interrupt type\n");
+// Caller is expected to have locked the apic
+static int get_highest_irr(struct apic_state * apic) {
+    int i = 0, j = 0;
+
+    // We iterate backwards to find the highest priority
+    for (i = 31; i >= 0; i--) {
+       uint8_t  * req_major = apic->int_req_reg + i;
+    
+       if ((*req_major) & 0xff) {
+           for (j = 7; j >= 0; j--) {
+               uint8_t flag = 0x1 << j;
+               if ((*req_major) & flag) {
+                   return ((i * 8) + j);
+               }
+           }
+       }
+    }
+
     return -1;
-  }
+}
+
 
-  // interrupt is masked, don't send
-  if (masked == 1) {
-    PrintDebug("Inerrupt is masked\n");
+// Caller is expected to have locked the apic
+static int apic_do_eoi(struct apic_state * apic) {
+    int isr_irq = get_highest_isr(apic);
+
+    if (isr_irq != -1) {
+       int major_offset = (isr_irq & ~0x00000007) >> 3;
+       int minor_offset = isr_irq & 0x00000007;
+       uint8_t flag = 0x1 << minor_offset;
+       uint8_t * svc_location = apic->int_svc_reg + major_offset;
+       
+       PrintDebug("apic %u: core ?: Received APIC EOI for IRQ %d\n", apic->lapic_id.val,isr_irq);
+       
+       *svc_location &= ~flag;
+
+#ifdef CONFIG_CRAY_XT
+       
+       if ((isr_irq == 238) || 
+           (isr_irq == 239)) {
+           PrintDebug("apic %u: core ?: Acking IRQ %d\n", apic->lapic_id.val,isr_irq);
+       }
+       
+       if (isr_irq == 238) {
+           V3_ACK_IRQ(238);
+       }
+#endif
+    } else {
+       //PrintError("apic %u: core ?: Spurious EOI...\n",apic->lapic_id.val);
+    }
+       
     return 0;
-  }
+}
+// Caller is expected to have locked the apic
+static int activate_internal_irq_nolock(struct apic_state * apic, apic_irq_type_t int_type) {
+    uint32_t vec_num = 0;
+    uint32_t del_mode = 0;
+    int masked = 0;
+
+
+    switch (int_type) {
+       case APIC_TMR_INT:
+           vec_num = apic->tmr_vec_tbl.vec;
+           del_mode = APIC_FIXED_DELIVERY;
+           masked = apic->tmr_vec_tbl.mask;
+           break;
+       case APIC_THERM_INT:
+           vec_num = apic->therm_loc_vec_tbl.vec;
+           del_mode = apic->therm_loc_vec_tbl.msg_type;
+           masked = apic->therm_loc_vec_tbl.mask;
+           break;
+       case APIC_PERF_INT:
+           vec_num = apic->perf_ctr_loc_vec_tbl.vec;
+           del_mode = apic->perf_ctr_loc_vec_tbl.msg_type;
+           masked = apic->perf_ctr_loc_vec_tbl.mask;
+           break;
+       case APIC_LINT0_INT:
+           vec_num = apic->lint0_vec_tbl.vec;
+           del_mode = apic->lint0_vec_tbl.msg_type;
+           masked = apic->lint0_vec_tbl.mask;
+           break;
+       case APIC_LINT1_INT:
+           vec_num = apic->lint1_vec_tbl.vec;
+           del_mode = apic->lint1_vec_tbl.msg_type;
+           masked = apic->lint1_vec_tbl.mask;
+           break;
+       case APIC_ERR_INT:
+           vec_num = apic->err_vec_tbl.vec;
+           del_mode = APIC_FIXED_DELIVERY;
+           masked = apic->err_vec_tbl.mask;
+           break;
+       default:
+           PrintError("apic %u: core ?: Invalid APIC interrupt type\n", apic->lapic_id.val);
+           return -1;
+    }
+
+    // interrupt is masked, don't send
+    if (masked == 1) {
+       PrintDebug("apic %u: core ?: Inerrupt is masked\n", apic->lapic_id.val);
+       return 0;
+    }
+
+    if (del_mode == APIC_FIXED_DELIVERY) {
+       //PrintDebug("Activating internal APIC IRQ %d\n", vec_num);
+       return activate_apic_irq_nolock(apic, vec_num);
+    } else {
+       PrintError("apic %u: core ?: Unhandled Delivery Mode\n", apic->lapic_id.val);
+       return -1;
+    }
+}
+
+
+// Caller is expected to have locked the destination apic
+static inline int should_deliver_cluster_ipi(struct guest_info * dst_core, 
+                                            struct apic_state * dst_apic, uint8_t mda) {
+
+    if         ( ((mda & 0xf0) == (dst_apic->log_dst.dst_log_id & 0xf0)) &&  /* (I am in the cluster and */
+         ((mda & 0x0f) & (dst_apic->log_dst.dst_log_id & 0x0f)) ) {  /*  I am in the set)        */
+
+       PrintDebug("apic %u core %u: accepting clustered IRQ (mda 0x%x == log_dst 0x%x)\n",
+                  dst_apic->lapic_id.val, dst_core->cpu_id, mda, 
+                  dst_apic->log_dst.dst_log_id);
+       
+       return 1;
+    } else {
+       PrintDebug("apic %u core %u: rejecting clustered IRQ (mda 0x%x != log_dst 0x%x)\n",
+                  dst_apic->lapic_id.val, dst_core->cpu_id, mda, 
+                  dst_apic->log_dst.dst_log_id);
+       return 0;
+    }
+}
+
+// Caller is expected to have locked the destiation apic
+static inline int should_deliver_flat_ipi(struct guest_info * dst_core,
+                                         struct apic_state * dst_apic, uint8_t mda) {
+
+    if (dst_apic->log_dst.dst_log_id & mda) {  // I am in the set 
+
+       PrintDebug("apic %u core %u: accepting flat IRQ (mda 0x%x == log_dst 0x%x)\n",
+                  dst_apic->lapic_id.val, dst_core->cpu_id, mda, 
+                  dst_apic->log_dst.dst_log_id);
+
+       return 1;
 
-  if (del_mode == APIC_FIXED_DELIVERY) {
-    //PrintDebug("Activating internal APIC IRQ %d\n", vec_num);
-    return activate_apic_irq(apic, vec_num);
   } else {
-    PrintError("Unhandled Delivery Mode\n");
-    return -1;
+
+       PrintDebug("apic %u core %u: rejecting flat IRQ (mda 0x%x != log_dst 0x%x)\n",
+                  dst_apic->lapic_id.val, dst_core->cpu_id, mda, 
+                  dst_apic->log_dst.dst_log_id);
+       return 0;
   }
 }
 
 
-static int apic_read(addr_t guest_addr, void * dst, uint_t length, void * priv_data) {
-  struct vm_device * dev = (struct vm_device *)priv_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  addr_t reg_addr  = guest_addr - apic->base_addr;
-  struct apic_msr * msr = (struct apic_msr *)&(apic->base_addr_msr.value);
-  uint32_t val = 0;
+// Caller is expected to have locked the destiation apic
+static int should_deliver_ipi(struct guest_info * dst_core, 
+                             struct apic_state * dst_apic, uint8_t mda) {
 
 
-  PrintDebug("Read apic address space (%p)\n", 
-            (void *)guest_addr);
+    if (dst_apic->dst_fmt.model == 0xf) {
 
-  if (msr->apic_enable == 0) {
-    PrintError("Write to APIC address space with disabled APIC\n");
-    return -1;
-  }
+       if (mda == 0xff) {
+           /* always deliver broadcast */
+           return 1;
+       }
+
+       return should_deliver_flat_ipi(dst_core, dst_apic, mda);
+
+    } else if (dst_apic->dst_fmt.model == 0x0) {
+
+       if (mda == 0xff) {
+           /*  always deliver broadcast */
+           return 1;
+       }
+
+       return should_deliver_cluster_ipi(dst_core, dst_apic, mda);
+
+    } else {
+       PrintError("apic %u core %u: invalid destination format register value 0x%x for logical mode delivery.\n", 
+                  dst_apic->lapic_id.val, dst_core->cpu_id, dst_apic->dst_fmt.model);
+       return -1;
+    }
+}
+
+// Caller is expected to have locked the destination apic
+// Only the src_apic pointer is used
+static int deliver_ipi(struct apic_state * src_apic, 
+                      struct apic_state * dst_apic, 
+                      uint32_t vector, uint8_t del_mode) {
+
+
+    struct guest_info * dst_core = dst_apic->core;
+    int do_xcall;
+
+    switch (del_mode) {
+
+       case APIC_FIXED_DELIVERY:  
+       case APIC_LOWEST_DELIVERY:
+           // lowest priority - 
+           // caller needs to have decided which apic to deliver to!
+
+           PrintDebug("delivering IRQ %d to core %u\n", vector, dst_core->cpu_id); 
+
+           do_xcall=activate_apic_irq_nolock(dst_apic, vector);
+           
+           if (do_xcall<0) { 
+               PrintError("Failed to activate apic irq!\n");
+               return -1;
+           }
+
+           if (do_xcall && (dst_apic != src_apic)) { 
+               // Assume core # is same as logical processor for now
+               // TODO FIX THIS FIX THIS
+               // THERE SHOULD BE:  guestapicid->virtualapicid map,
+               //                   cpu_id->logical processor map
+               //     host maitains logical proc->phsysical proc
+               PrintDebug(" non-local core with new interrupt, forcing it to exit now\n"); 
+
+#ifdef CONFIG_MULTITHREAD_OS
+               v3_interrupt_cpu(dst_core->vm_info, dst_core->cpu_id, 0);
+#else
+               V3_ASSERT(0);
+#endif
+           }
+
+           break;
+
+       case APIC_INIT_DELIVERY: { 
+
+           PrintDebug(" INIT delivery to core %u\n", dst_core->cpu_id);
+
+           // TODO: any APIC reset on dest core (shouldn't be needed, but not sure...)
+
+           // Sanity check
+           if (dst_apic->ipi_state != INIT_ST) { 
+               PrintError(" Warning: core %u is not in INIT state (mode = %d), ignored (assuming this is the deassert)\n",
+                          dst_core->cpu_id, dst_apic->ipi_state);
+               // Only a warning, since INIT INIT SIPI is common
+               break;
+           }
+
+           // We transition the target core to SIPI state
+           dst_apic->ipi_state = SIPI;  // note: locking should not be needed here
+
+           // That should be it since the target core should be
+           // waiting in host on this transition
+           // either it's on another core or on a different preemptive thread
+           // in both cases, it will quickly notice this transition 
+           // in particular, we should not need to force an exit here
+
+           PrintDebug(" INIT delivery done\n");
+
+           break;                                                      
+       }
+       case APIC_SIPI_DELIVERY: { 
+
+           // Sanity check
+           if (dst_apic->ipi_state != SIPI) { 
+               PrintError(" core %u is not in SIPI state (mode = %d), ignored!\n",
+                          dst_core->cpu_id, dst_apic->ipi_state);
+               break;
+           }
+
+           // Write the RIP, CS, and descriptor
+           // assume the rest is already good to go
+           //
+           // vector VV -> rip at 0
+           //              CS = VV00
+           //  This means we start executing at linear address VV000
+           //
+           // So the selector needs to be VV00
+           // and the base needs to be VV000
+           //
+           dst_core->rip = 0;
+           dst_core->segments.cs.selector = vector << 8;
+           dst_core->segments.cs.limit = 0xffff;
+           dst_core->segments.cs.base = vector << 12;
+
+           PrintDebug(" SIPI delivery (0x%x -> 0x%x:0x0) to core %u\n",
+                      vector, dst_core->segments.cs.selector, dst_core->cpu_id);
+           // Maybe need to adjust the APIC?
+           
+           // We transition the target core to SIPI state
+           dst_core->core_run_state = CORE_RUNNING;  // note: locking should not be needed here
+           dst_apic->ipi_state = STARTED;
+           
+           // As with INIT, we should not need to do anything else
+           
+           PrintDebug(" SIPI delivery done\n");
+           
+           break;                                                      
+       }
+       case APIC_SMI_DELIVERY: 
+       case APIC_RES1_DELIVERY: // reserved                                            
+       case APIC_NMI_DELIVERY:
+       case APIC_EXTINT_DELIVERY: // ExtInt
+       default:
+           PrintError("IPI %d delivery is unsupported\n", del_mode); 
+           return -1;
+    }
+    
+    return 0;
+    
+}
+
+static struct apic_state * find_physical_apic(struct apic_dev_state *apic_dev, struct int_cmd_reg *icr)
+{
+    int i;
+    
+    if (icr->dst >0 && icr->dst < apic_dev->num_apics) { 
+       // see if it simply is the core id
+       if (apic_dev->apics[icr->dst].lapic_id.val == icr->dst) { 
+           return &(apic_dev->apics[icr->dst]);
+       }
+    }
+
+    for (i=0;i<apic_dev->num_apics;i++) { 
+       if (apic_dev->apics[i].lapic_id.val == icr->dst) { 
+           return &(apic_dev->apics[i]);
+       }
+    }
+    
+    return NULL;
+
+}
 
+// route_ipi is responsible for all locking
+// the assumption is that you enter with no locks
+// there is a global lock for the icc bus, so only
+// one route_ipi progresses at any time
+// destination apics are locked as needed
+// if multiple apic locks are acquired at any point,
+// this is done in the order of the array, so no
+// deadlock should be possible
+static int route_ipi(struct apic_dev_state * apic_dev,
+                    struct apic_state * src_apic, 
+                    struct int_cmd_reg * icr) {
+    struct apic_state * dest_apic = NULL;
+
+
+    //v3_lock(apic_dev->ipi_lock);  // this may not be needed
+    // now I know only one IPI is being routed, this one
+    // also, I do not have any apic locks
+    // I need to acquire locks on pairs of src/dest apics
+    // and I will do that using the total order
+    // given by their cores
+
+
+    PrintDebug("apic: IPI %s %u from apic %p to %s %s %u (icr=0x%llx)\n",
+              deliverymode_str[icr->del_mode], 
+              icr->vec, 
+              src_apic,               
+              (icr->dst_mode == 0) ? "(physical)" : "(logical)", 
+              shorthand_str[icr->dst_shorthand], 
+              icr->dst,
+              icr->val);
+
+#if 0
+        if (icr->vec!=48) { 
+           V3_Print("apic: IPI %s %u from apic %p to %s %s %u (icr=0x%llx)\n",
+                   deliverymode_str[icr->del_mode], 
+                   icr->vec, 
+                   src_apic,          
+                   (icr->dst_mode == 0) ? "(physical)" : "(logical)", 
+                   shorthand_str[icr->dst_shorthand], 
+                   icr->dst,
+                   icr->val);
+       }
+
+#endif
+
+
+    switch (icr->dst_shorthand) {
+
+       case APIC_SHORTHAND_NONE:  // no shorthand
+           if (icr->dst_mode == APIC_DEST_PHYSICAL) { 
+
+               dest_apic=find_physical_apic(apic_dev,icr);
+               
+               if (dest_apic==NULL) { 
+                   PrintError("apic: Attempted send to unregistered apic id=%u\n", icr->dst);
+                   goto route_ipi_out_bad;
+               }
+
+
+       
+               //V3_Print("apic: phsyical destination of %u (apic %u at 0x%p)\n", icr->dst,dest_apic->lapic_id.val,dest_apic);
+
+               v3_lock(dest_apic->lock);
+
+               if (deliver_ipi(src_apic, dest_apic, 
+                               icr->vec, icr->del_mode) == -1) {
+                   PrintError("apic: Could not deliver IPI\n");
+                   v3_unlock(dest_apic->lock);
+                   goto route_ipi_out_bad;
+               }
+
+               v3_unlock(dest_apic->lock);
+
+               //V3_Print("apic: done\n");
+
+           } else if (icr->dst_mode == APIC_DEST_LOGICAL) {
+               
+               if (icr->del_mode!=APIC_LOWEST_DELIVERY ) { 
+                   // logical, but not lowest priority
+                   // we immediately trigger
+                   // fixed, smi, reserved, nmi, init, sipi, etc
+                   int i;
+                   
+                   uint8_t mda = icr->dst;
+                   
+                   for (i = 0; i < apic_dev->num_apics; i++) { 
+                       
+                       dest_apic = &(apic_dev->apics[i]);
+                       
+                       v3_lock(dest_apic->lock);
+                       
+                       int del_flag = should_deliver_ipi(dest_apic->core, dest_apic, mda);
+                       
+                       if (del_flag == -1) {
+                           PrintError("apic: Error checking delivery mode\n");
+                           v3_unlock(dest_apic->lock);
+                           goto route_ipi_out_bad;
+                       } else if (del_flag == 1) {
+                           if (deliver_ipi(src_apic, dest_apic, 
+                                           icr->vec, icr->del_mode) == -1) {
+                               PrintError("apic: Error: Could not deliver IPI\n");
+                               v3_unlock(dest_apic->lock);
+                               goto route_ipi_out_bad;
+                           }
+                       }
+                       
+                       v3_unlock(dest_apic->lock);
+                   }
+               } else {  //APIC_LOWEST_DELIVERY
+                   // logical, lowest priority
+                   // scan, keeping a lock on the current best, then trigger
+                   int i;
+                   int have_cur_lock;
+                   struct apic_state * cur_best_apic = NULL;
+                   
+                   uint8_t mda = icr->dst;
+                   
+                   have_cur_lock=0;
+
+
+                   // Note that even if there are multiple concurrent 
+                   // copies of this loop executing, they are all 
+                   // locking in the same order
+
+                   for (i = 0; i < apic_dev->num_apics; i++) { 
+                       
+                       dest_apic = &(apic_dev->apics[i]);
+                       
+                       v3_lock(dest_apic->lock);
+                       have_cur_lock=1;
+                       
+                       int del_flag = should_deliver_ipi(dest_apic->core, dest_apic, mda);
+                       
+                       if (del_flag == -1) {
+                           PrintError("apic: Error checking delivery mode\n");
+                           v3_unlock(dest_apic->lock);
+                           if (cur_best_apic && cur_best_apic!=dest_apic) { 
+                               v3_unlock(cur_best_apic->lock);
+                           }
+                           goto route_ipi_out_bad;
+                       } else if (del_flag == 1) {
+                           // update priority for lowest priority scan
+                           if (!cur_best_apic) {
+                               cur_best_apic=dest_apic;  // note we leave it locked
+                               have_cur_lock=0;          // we will unlock as cur_best_apic
+                           } else if (dest_apic->task_prio.val < cur_best_apic->task_prio.val) {
+                               // we now unlock the current best one and then switch
+                               // so in the end we have a lock on the new cur_best_apic
+                               v3_unlock(cur_best_apic->lock);
+                               cur_best_apic=dest_apic;
+                               have_cur_lock=0; // will unlock as cur_best_apic
+                           } 
+                       }
+                       if (have_cur_lock) {
+                           v3_unlock(dest_apic->lock);
+                       }
+                       
+                   }
+                   // now we will deliver to the best one if it exists
+                   // and it is locked
+                   if (!cur_best_apic) { 
+                       PrintDebug("apic: lowest priority deliver, but no destinations!\n");
+                   } else {
+                       if (deliver_ipi(src_apic, cur_best_apic, 
+                                       icr->vec, icr->del_mode) == -1) {
+                           PrintError("apic: Error: Could not deliver IPI\n");
+                           v3_unlock(cur_best_apic->lock);
+                           goto route_ipi_out_bad;
+                       } else {
+                           v3_unlock(cur_best_apic->lock);
+                       }
+                           //V3_Print("apic: logical, lowest priority delivery to apic %u\n",cur_best_apic->lapic_id.val);
+                   }
+               }
+           }
+
+           break;
+           
+       case APIC_SHORTHAND_SELF:  // self
+
+           /* I assume I am already locked! */
+
+           if (src_apic == NULL) {    /* this is not an apic, but it's trying to send to itself??? */
+               PrintError("apic: Sending IPI to self from generic IPI sender\n");
+               break;
+           }
+
+           v3_lock(src_apic->lock);
+
+           if (icr->dst_mode == APIC_DEST_PHYSICAL)  {  /* physical delivery */
+               if (deliver_ipi(src_apic, src_apic, icr->vec, icr->del_mode) == -1) {
+                   PrintError("apic: Could not deliver IPI to self (physical)\n");
+                   v3_unlock(src_apic->lock);
+                   goto route_ipi_out_bad;
+               }
+           } else if (icr->dst_mode == APIC_DEST_LOGICAL) {  /* logical delivery */
+               PrintError("apic: use of logical delivery in self (untested)\n");
+               if (deliver_ipi(src_apic, src_apic, icr->vec, icr->del_mode) == -1) {
+                   PrintError("apic: Could not deliver IPI to self (logical)\n");
+                   v3_unlock(src_apic->lock);
+                   goto route_ipi_out_bad;
+               }
+           }
+           v3_unlock(src_apic->lock);
+           break;
+           
+       case APIC_SHORTHAND_ALL: 
+       case APIC_SHORTHAND_ALL_BUT_ME: { /* all and all-but-me */
+           /* assuming that logical verus physical doesn't matter
+              although it is odd that both are used */
+
+           int i;
+
+           for (i = 0; i < apic_dev->num_apics; i++) { 
+               dest_apic = &(apic_dev->apics[i]);
+               
+               
+               if ((dest_apic != src_apic) || (icr->dst_shorthand == APIC_SHORTHAND_ALL)) { 
+                   v3_lock(dest_apic->lock);
+                   if (deliver_ipi(src_apic, dest_apic, icr->vec, icr->del_mode) == -1) {
+                       PrintError("apic: Error: Could not deliver IPI\n");
+                       v3_unlock(dest_apic->lock);
+                       goto route_ipi_out_bad;
+                   }
+                   v3_unlock(dest_apic->lock);
+               }
+               
+           }
+       }
+           break;
+       default:
+           PrintError("apic: Error routing IPI, invalid Mode (%d)\n", icr->dst_shorthand);
+           goto route_ipi_out_bad;
+    }
 
-  /* Because "May not be supported" doesn't matter to Linux developers... */
-  /*   if (length != 4) { */
-  /*     PrintError("Invalid apic read length (%d)\n", length); */
-  /*     return -1; */
-  /*   } */
 
-  switch (reg_addr & ~0x3) {
-  case EOI_OFFSET:
-    PrintError("Attempting to read from write only register\n");
+    // route_ipi_out_good:
+    //v3_unlock(apic_dev->ipi_lock);  
+    return 0;
+
+ route_ipi_out_bad:
+    //v3_unlock(apic_dev->ipi_lock);  
     return -1;
-    break;
-
-    // data registers
-  case APIC_ID_OFFSET:
-    val = apic->lapic_id.val;
-    break;
-  case APIC_VERSION_OFFSET:
-    val = apic->apic_ver.val;
-    break;
-  case TPR_OFFSET:
-    val = apic->task_prio.val;
-    break;
-  case APR_OFFSET:
-    val = apic->arb_prio.val;
-    break;
-  case PPR_OFFSET:
-    val = apic->proc_prio.val;
-    break;
-  case REMOTE_READ_OFFSET:
-    val = apic->rem_rd_data;
-    break;
-  case LDR_OFFSET:
-    val = apic->log_dst.val;
-    break;
-  case DFR_OFFSET:
-    val = apic->dst_fmt.val;
-    break;
-  case SPURIOUS_INT_VEC_OFFSET:
-    val = apic->spurious_int.val;
-    break;
-  case ESR_OFFSET:
-    val = apic->err_status.val;
-    break;
-  case TMR_LOC_VEC_TBL_OFFSET:
-    val = apic->tmr_vec_tbl.val;
-    break;
-  case LINT0_VEC_TBL_OFFSET:
-    val = apic->lint0_vec_tbl.val;
-    break;
-  case LINT1_VEC_TBL_OFFSET:
-    val = apic->lint1_vec_tbl.val;
-    break;
-  case ERR_VEC_TBL_OFFSET:
-    val = apic->err_vec_tbl.val;
-    break;
-  case TMR_INIT_CNT_OFFSET:
-    val = apic->tmr_init_cnt;
-    break;
-  case TMR_DIV_CFG_OFFSET:
-    val = apic->tmr_div_cfg.val;
-    break;
-
-  case IER_OFFSET0:
-    val = *(uint32_t *)(apic->int_en_reg);
-    break;
-  case IER_OFFSET1:
-    val = *(uint32_t *)(apic->int_en_reg + 4);
-    break;
-  case IER_OFFSET2:
-    val = *(uint32_t *)(apic->int_en_reg + 8);
-    break;
-  case IER_OFFSET3:
-    val = *(uint32_t *)(apic->int_en_reg + 12);
-    break;
-  case IER_OFFSET4:
-    val = *(uint32_t *)(apic->int_en_reg + 16);
-    break;
-  case IER_OFFSET5:
-    val = *(uint32_t *)(apic->int_en_reg + 20);
-    break;
-  case IER_OFFSET6:
-    val = *(uint32_t *)(apic->int_en_reg + 24);
-    break;
-  case IER_OFFSET7:
-    val = *(uint32_t *)(apic->int_en_reg + 28);
-    break;
-
-  case ISR_OFFSET0:
-    val = *(uint32_t *)(apic->int_svc_reg);
-    break;
-  case ISR_OFFSET1:
-    val = *(uint32_t *)(apic->int_svc_reg + 4);
-    break;
-  case ISR_OFFSET2:
-    val = *(uint32_t *)(apic->int_svc_reg + 8);
-    break;
-  case ISR_OFFSET3:
-    val = *(uint32_t *)(apic->int_svc_reg + 12);
-    break;
-  case ISR_OFFSET4:
-    val = *(uint32_t *)(apic->int_svc_reg + 16);
-    break;
-  case ISR_OFFSET5:
-    val = *(uint32_t *)(apic->int_svc_reg + 20);
-    break;
-  case ISR_OFFSET6:
-    val = *(uint32_t *)(apic->int_svc_reg + 24);
-    break;
-  case ISR_OFFSET7:
-    val = *(uint32_t *)(apic->int_svc_reg + 28);
-    break;
+}
+
+
+// External function, expected to acquire lock on apic
+static int apic_read(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(priv_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]);
+    addr_t reg_addr  = guest_addr - apic->base_addr;
+    struct apic_msr * msr = (struct apic_msr *)&(apic->base_addr_msr.value);
+    uint32_t val = 0;
+
+    v3_lock(apic->lock);
+
+    PrintDebug("apic %u: core %u: at %p: Read apic address space (%p)\n",
+              apic->lapic_id.val, core->cpu_id, apic, (void *)guest_addr);
+
+    if (msr->apic_enable == 0) {
+       PrintError("apic %u: core %u: Read from APIC address space with disabled APIC, apic msr=0x%llx\n",
+                  apic->lapic_id.val, core->cpu_id, apic->base_addr_msr.value);
+
+       goto apic_read_out_bad;
+    }
+
+
+    /* Because "May not be supported" doesn't matter to Linux developers... */
+    /*   if (length != 4) { */
+    /*     PrintError("Invalid apic read length (%d)\n", length); */
+    /*     return -1; */
+    /*   } */
+
+    switch (reg_addr & ~0x3) {
+       case EOI_OFFSET:
+           // Well, only an idiot would read from a architectural write only register
+           // Oh, Hello Linux.
+           //    PrintError("Attempting to read from write only register\n");
+           //    return -1;
+           break;
+
+           // data registers
+       case APIC_ID_OFFSET:
+           val = apic->lapic_id.val;
+           break;
+       case APIC_VERSION_OFFSET:
+           val = apic->apic_ver.val;
+           break;
+       case TPR_OFFSET:
+           val = apic->task_prio.val;
+           break;
+       case APR_OFFSET:
+           val = apic->arb_prio.val;
+           break;
+       case PPR_OFFSET:
+           val = apic->proc_prio.val;
+           break;
+       case REMOTE_READ_OFFSET:
+           val = apic->rem_rd_data;
+           break;
+       case LDR_OFFSET:
+           val = apic->log_dst.val;
+           break;
+       case DFR_OFFSET:
+           val = apic->dst_fmt.val;
+           break;
+       case SPURIOUS_INT_VEC_OFFSET:
+           val = apic->spurious_int.val;
+           break;
+       case ESR_OFFSET:
+           val = apic->err_status.val;
+           break;
+       case TMR_LOC_VEC_TBL_OFFSET:
+           val = apic->tmr_vec_tbl.val;
+           break;
+       case LINT0_VEC_TBL_OFFSET:
+           val = apic->lint0_vec_tbl.val;
+           break;
+       case LINT1_VEC_TBL_OFFSET:
+           val = apic->lint1_vec_tbl.val;
+           break;
+       case ERR_VEC_TBL_OFFSET:
+           val = apic->err_vec_tbl.val;
+           break;
+       case TMR_INIT_CNT_OFFSET:
+           val = apic->tmr_init_cnt;
+           break;
+       case TMR_DIV_CFG_OFFSET:
+           val = apic->tmr_div_cfg.val;
+           break;
+
+       case IER_OFFSET0:
+           val = *(uint32_t *)(apic->int_en_reg);
+           break;
+       case IER_OFFSET1:
+           val = *(uint32_t *)(apic->int_en_reg + 4);
+           break;
+       case IER_OFFSET2:
+           val = *(uint32_t *)(apic->int_en_reg + 8);
+           break;
+       case IER_OFFSET3:
+           val = *(uint32_t *)(apic->int_en_reg + 12);
+           break;
+       case IER_OFFSET4:
+           val = *(uint32_t *)(apic->int_en_reg + 16);
+           break;
+       case IER_OFFSET5:
+           val = *(uint32_t *)(apic->int_en_reg + 20);
+           break;
+       case IER_OFFSET6:
+           val = *(uint32_t *)(apic->int_en_reg + 24);
+           break;
+       case IER_OFFSET7:
+           val = *(uint32_t *)(apic->int_en_reg + 28);
+           break;
+
+       case ISR_OFFSET0:
+           val = *(uint32_t *)(apic->int_svc_reg);
+           break;
+       case ISR_OFFSET1:
+           val = *(uint32_t *)(apic->int_svc_reg + 4);
+           break;
+       case ISR_OFFSET2:
+           val = *(uint32_t *)(apic->int_svc_reg + 8);
+           break;
+       case ISR_OFFSET3:
+           val = *(uint32_t *)(apic->int_svc_reg + 12);
+           break;
+       case ISR_OFFSET4:
+           val = *(uint32_t *)(apic->int_svc_reg + 16);
+           break;
+       case ISR_OFFSET5:
+           val = *(uint32_t *)(apic->int_svc_reg + 20);
+           break;
+       case ISR_OFFSET6:
+           val = *(uint32_t *)(apic->int_svc_reg + 24);
+           break;
+       case ISR_OFFSET7:
+           val = *(uint32_t *)(apic->int_svc_reg + 28);
+           break;
    
-  case TRIG_OFFSET0:
-    val = *(uint32_t *)(apic->trig_mode_reg);
-    break;
-  case TRIG_OFFSET1:
-    val = *(uint32_t *)(apic->trig_mode_reg + 4);
-    break;
-  case TRIG_OFFSET2:
-    val = *(uint32_t *)(apic->trig_mode_reg + 8);
-    break;
-  case TRIG_OFFSET3:
-    val = *(uint32_t *)(apic->trig_mode_reg + 12);
-    break;
-  case TRIG_OFFSET4:
-    val = *(uint32_t *)(apic->trig_mode_reg + 16);
-    break;
-  case TRIG_OFFSET5:
-    val = *(uint32_t *)(apic->trig_mode_reg + 20);
-    break;
-  case TRIG_OFFSET6:
-    val = *(uint32_t *)(apic->trig_mode_reg + 24);
-    break;
-  case TRIG_OFFSET7:
-    val = *(uint32_t *)(apic->trig_mode_reg + 28);
-    break;
-
-  case IRR_OFFSET0:
-    val = *(uint32_t *)(apic->int_req_reg);
-    break;
-  case IRR_OFFSET1:
-    val = *(uint32_t *)(apic->int_req_reg + 4);
-    break;
-  case IRR_OFFSET2:
-    val = *(uint32_t *)(apic->int_req_reg + 8);
-    break;
-  case IRR_OFFSET3:
-    val = *(uint32_t *)(apic->int_req_reg + 12);
-    break;
-  case IRR_OFFSET4:
-    val = *(uint32_t *)(apic->int_req_reg + 16);
-    break;
-  case IRR_OFFSET5:
-    val = *(uint32_t *)(apic->int_req_reg + 20);
-    break;
-  case IRR_OFFSET6:
-    val = *(uint32_t *)(apic->int_req_reg + 24);
-    break;
-  case IRR_OFFSET7:
-    val = *(uint32_t *)(apic->int_req_reg + 28);
-    break;
-  case TMR_CUR_CNT_OFFSET:
-    val = apic->tmr_cur_cnt;
-    break;
-
-    // We are not going to implement these....
-  case THERM_LOC_VEC_TBL_OFFSET:
-    val = apic->therm_loc_vec_tbl.val;
-    break;
-  case PERF_CTR_LOC_VEC_TBL_OFFSET:
-    val = apic->perf_ctr_loc_vec_tbl.val;
-    break;
+       case TRIG_OFFSET0:
+           val = *(uint32_t *)(apic->trig_mode_reg);
+           break;
+       case TRIG_OFFSET1:
+           val = *(uint32_t *)(apic->trig_mode_reg + 4);
+           break;
+       case TRIG_OFFSET2:
+           val = *(uint32_t *)(apic->trig_mode_reg + 8);
+           break;
+       case TRIG_OFFSET3:
+           val = *(uint32_t *)(apic->trig_mode_reg + 12);
+           break;
+       case TRIG_OFFSET4:
+           val = *(uint32_t *)(apic->trig_mode_reg + 16);
+           break;
+       case TRIG_OFFSET5:
+           val = *(uint32_t *)(apic->trig_mode_reg + 20);
+           break;
+       case TRIG_OFFSET6:
+           val = *(uint32_t *)(apic->trig_mode_reg + 24);
+           break;
+       case TRIG_OFFSET7:
+           val = *(uint32_t *)(apic->trig_mode_reg + 28);
+           break;
+
+       case IRR_OFFSET0:
+           val = *(uint32_t *)(apic->int_req_reg);
+           break;
+       case IRR_OFFSET1:
+           val = *(uint32_t *)(apic->int_req_reg + 4);
+           break;
+       case IRR_OFFSET2:
+           val = *(uint32_t *)(apic->int_req_reg + 8);
+           break;
+       case IRR_OFFSET3:
+           val = *(uint32_t *)(apic->int_req_reg + 12);
+           break;
+       case IRR_OFFSET4:
+           val = *(uint32_t *)(apic->int_req_reg + 16);
+           break;
+       case IRR_OFFSET5:
+           val = *(uint32_t *)(apic->int_req_reg + 20);
+           break;
+       case IRR_OFFSET6:
+           val = *(uint32_t *)(apic->int_req_reg + 24);
+           break;
+       case IRR_OFFSET7:
+           val = *(uint32_t *)(apic->int_req_reg + 28);
+           break;
+       case TMR_CUR_CNT_OFFSET:
+           val = apic->tmr_cur_cnt;
+           break;
+
+           // We are not going to implement these....
+       case THERM_LOC_VEC_TBL_OFFSET:
+           val = apic->therm_loc_vec_tbl.val;
+           break;
+       case PERF_CTR_LOC_VEC_TBL_OFFSET:
+           val = apic->perf_ctr_loc_vec_tbl.val;
+           break;
 
  
 
-    // handled registers
-  case INT_CMD_LO_OFFSET:    
-    val = apic->int_cmd.lo;
-    break;
-  case INT_CMD_HI_OFFSET:
-    val = apic->int_cmd.hi;
-    break;
-
-    // handle current timer count
-
-    // Unhandled Registers
-  case EXT_INT_LOC_VEC_TBL_OFFSET0:
-  case EXT_INT_LOC_VEC_TBL_OFFSET1:
-  case EXT_INT_LOC_VEC_TBL_OFFSET2:
-  case EXT_INT_LOC_VEC_TBL_OFFSET3:
-  case EXT_APIC_FEATURE_OFFSET:
-  case EXT_APIC_CMD_OFFSET:
-  case SEOI_OFFSET:
-
-  default:
-    PrintError("Read from Unhandled APIC Register: %x\n", (uint32_t)reg_addr);
-    return -1;
-  }
+           // handled registers
+       case INT_CMD_LO_OFFSET:    
+           val = apic->int_cmd.lo;
+           break;
+       case INT_CMD_HI_OFFSET:
+           val = apic->int_cmd.hi;
+           break;
+
+           // handle current timer count
+
+           // Unhandled Registers
+       case EXT_INT_LOC_VEC_TBL_OFFSET0:
+           val = apic->ext_intr_vec_tbl[0].val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET1:
+           val = apic->ext_intr_vec_tbl[1].val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET2:
+           val = apic->ext_intr_vec_tbl[2].val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET3:
+           val = apic->ext_intr_vec_tbl[3].val;
+           break;
+    
 
+       case EXT_APIC_FEATURE_OFFSET:
+       case EXT_APIC_CMD_OFFSET:
+       case SEOI_OFFSET:
+
+       default:
+           PrintError("apic %u: core %u: Read from Unhandled APIC Register: %x (getting zero)\n", 
+                      apic->lapic_id.val, core->cpu_id, (uint32_t)reg_addr);
+           goto apic_read_out_bad;
+    }
 
-  if (length == 1) {
-    uint_t byte_addr = reg_addr & 0x3;
-    uint8_t * val_ptr = (uint8_t *)dst;
+
+    if (length == 1) {
+       uint_t byte_addr = reg_addr & 0x3;
+       uint8_t * val_ptr = (uint8_t *)dst;
     
-    *val_ptr = *(((uint8_t *)&val) + byte_addr);
+       *val_ptr = *(((uint8_t *)&val) + byte_addr);
+
+    } else if ((length == 2) && 
+              ((reg_addr & 0x3) == 0x3)) {
+       uint_t byte_addr = reg_addr & 0x3;
+       uint16_t * val_ptr = (uint16_t *)dst;
+       *val_ptr = *(((uint16_t *)&val) + byte_addr);
+
+    } else if (length == 4) {
+       uint32_t * val_ptr = (uint32_t *)dst;
+       *val_ptr = val;
+
+    } else {
+       PrintError("apic %u: core %u: Invalid apic read length (%d)\n", 
+                  apic->lapic_id.val, core->cpu_id, length);
+       goto apic_read_out_bad;
+    }
 
-  } else if ((length == 2) && 
-            ((reg_addr & 0x3) == 0x3)) {
-    uint_t byte_addr = reg_addr & 0x3;
-    uint16_t * val_ptr = (uint16_t *)dst;
-    *val_ptr = *(((uint16_t *)&val) + byte_addr);
+    PrintDebug("apic %u: core %u: Read finished (val=%x)\n", 
+              apic->lapic_id.val, core->cpu_id, *(uint32_t *)dst);
 
-  } else if (length == 4) {
-    uint32_t * val_ptr = (uint32_t *)dst;
-    *val_ptr = val;
 
-  } else {
-    PrintError("Invalid apic read length (%d)\n", length);
+    // apic_read_out_good:
+    v3_unlock(apic->lock);
+    return length;
+
+ apic_read_out_bad:
+    v3_unlock(apic->lock);
     return -1;
-  }
+}
 
-  PrintDebug("Read finished (val=%x)\n", *(uint32_t *)dst);
 
-  return length;
-}
+/**
+ *
+ */
+static int apic_write(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(priv_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    addr_t reg_addr  = guest_addr - apic->base_addr;
+    struct apic_msr * msr = (struct apic_msr *)&(apic->base_addr_msr.value);
+    uint32_t op_val = *(uint32_t *)src;
 
 
-static int apic_write(addr_t guest_addr, void * src, uint_t length, void * priv_data) {
-  struct vm_device * dev = (struct vm_device *)priv_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  addr_t reg_addr  = guest_addr - apic->base_addr;
-  struct apic_msr * msr = (struct apic_msr *)&(apic->base_addr_msr.value);
-  uint32_t op_val = *(uint32_t *)src;
+    v3_lock(apic->lock);
 
-  PrintDebug("Write to apic address space (%p) (val=%x)\n", 
-            (void *)guest_addr, *(uint32_t *)src);
+    PrintDebug("apic %u: core %u: at %p and priv_data is at %p\n",
+              apic->lapic_id.val, core->cpu_id, apic, priv_data);
 
-  if (msr->apic_enable == 0) {
-    PrintError("Write to APIC address space with disabled APIC\n");
-    return -1;
-  }
+    PrintDebug("apic %u: core %u: write to address space (%p) (val=%x)\n", 
+              apic->lapic_id.val, core->cpu_id, (void *)guest_addr, *(uint32_t *)src);
 
+    if (msr->apic_enable == 0) {
+       PrintError("apic %u: core %u: Write to APIC address space with disabled APIC, apic msr=0x%llx\n",
+                  apic->lapic_id.val, core->cpu_id, apic->base_addr_msr.value);
+       goto apic_write_out_bad;
+    }
 
-  if (length != 4) {
-    PrintError("Invalid apic write length (%d)\n", length);
-    return -1;
-  }
 
-  switch (reg_addr) {
-  case REMOTE_READ_OFFSET:
-  case APIC_VERSION_OFFSET:
-  case APR_OFFSET:
-  case IRR_OFFSET0:
-  case IRR_OFFSET1:
-  case IRR_OFFSET2:
-  case IRR_OFFSET3:
-  case IRR_OFFSET4:
-  case IRR_OFFSET5:
-  case IRR_OFFSET6:
-  case IRR_OFFSET7:
-  case ISR_OFFSET0:
-  case ISR_OFFSET1:
-  case ISR_OFFSET2:
-  case ISR_OFFSET3:
-  case ISR_OFFSET4:
-  case ISR_OFFSET5:
-  case ISR_OFFSET6:
-  case ISR_OFFSET7:
-  case TRIG_OFFSET0:
-  case TRIG_OFFSET1:
-  case TRIG_OFFSET2:
-  case TRIG_OFFSET3:
-  case TRIG_OFFSET4:
-  case TRIG_OFFSET5:
-  case TRIG_OFFSET6:
-  case TRIG_OFFSET7:
-  case PPR_OFFSET:
-  case EXT_APIC_FEATURE_OFFSET:
-    PrintError("Attempting to write to read only register %p\n", (void *)reg_addr);
-    return -1;
-    break;
-
-    // Data registers
-  case APIC_ID_OFFSET:
-    apic->lapic_id.val = op_val;
-    break;
-  case TPR_OFFSET:
-    apic->task_prio.val = op_val;
-    break;
-  case LDR_OFFSET:
-    apic->log_dst.val = op_val;
-    break;
-  case DFR_OFFSET:
-    apic->dst_fmt.val = op_val;
-    break;
-  case SPURIOUS_INT_VEC_OFFSET:
-    apic->spurious_int.val = op_val;
-    break;
-  case ESR_OFFSET:
-    apic->err_status.val = op_val;
-    break;
-  case TMR_LOC_VEC_TBL_OFFSET:
-    apic->tmr_vec_tbl.val = op_val;
-    break;
-  case THERM_LOC_VEC_TBL_OFFSET:
-    apic->therm_loc_vec_tbl.val = op_val;
-    break;
-  case PERF_CTR_LOC_VEC_TBL_OFFSET:
-    apic->perf_ctr_loc_vec_tbl.val = op_val;
-    break;
-  case LINT0_VEC_TBL_OFFSET:
-    apic->lint0_vec_tbl.val = op_val;
-    break;
-  case LINT1_VEC_TBL_OFFSET:
-    apic->lint1_vec_tbl.val = op_val;
-    break;
-  case ERR_VEC_TBL_OFFSET:
-    apic->err_vec_tbl.val = op_val;
-    break;
-  case TMR_INIT_CNT_OFFSET:
-    apic->tmr_init_cnt = op_val;
-    apic->tmr_cur_cnt = op_val;
-    break;
-  case TMR_CUR_CNT_OFFSET:
-    apic->tmr_cur_cnt = op_val;
-    break;
-  case TMR_DIV_CFG_OFFSET:
-    apic->tmr_div_cfg.val = op_val;
-    break;
-
-
-    // Enable mask (256 bits)
-  case IER_OFFSET0:
-    *(uint32_t *)(apic->int_en_reg) = op_val;
-    break;
-  case IER_OFFSET1:
-    *(uint32_t *)(apic->int_en_reg + 4) = op_val;
-    break;
-  case IER_OFFSET2:
-    *(uint32_t *)(apic->int_en_reg + 8) = op_val;
-    break;
-  case IER_OFFSET3:
-    *(uint32_t *)(apic->int_en_reg + 12) = op_val;
-    break;
-  case IER_OFFSET4:
-    *(uint32_t *)(apic->int_en_reg + 16) = op_val;
-    break;
-  case IER_OFFSET5:
-    *(uint32_t *)(apic->int_en_reg + 20) = op_val;
-    break;
-  case IER_OFFSET6:
-    *(uint32_t *)(apic->int_en_reg + 24) = op_val;
-    break;
-  case IER_OFFSET7:
-    *(uint32_t *)(apic->int_en_reg + 28) = op_val;
-    break;
-   
+    if (length != 4) {
+       PrintError("apic %u: core %u: Invalid apic write length (%d)\n", 
+                  apic->lapic_id.val, length, core->cpu_id);
+       goto apic_write_out_bad;
+    }
 
-    // Action Registers
-  case INT_CMD_LO_OFFSET:
-  case INT_CMD_HI_OFFSET:
-  case EOI_OFFSET:
-    {
-      // do eoi
-      apic_do_eoi(apic);
-      break;
-
-    }
-    // Unhandled Registers
-  case EXT_INT_LOC_VEC_TBL_OFFSET0:
-  case EXT_INT_LOC_VEC_TBL_OFFSET1:
-  case EXT_INT_LOC_VEC_TBL_OFFSET2:
-  case EXT_INT_LOC_VEC_TBL_OFFSET3:
-  case EXT_APIC_CMD_OFFSET:
-  case SEOI_OFFSET:
-  default:
-    PrintError("Write to Unhandled APIC Register: %x\n", (uint32_t)reg_addr);
-    return -1;
-  }
+    switch (reg_addr) {
+       case REMOTE_READ_OFFSET:
+       case APIC_VERSION_OFFSET:
+       case APR_OFFSET:
+       case IRR_OFFSET0:
+       case IRR_OFFSET1:
+       case IRR_OFFSET2:
+       case IRR_OFFSET3:
+       case IRR_OFFSET4:
+       case IRR_OFFSET5:
+       case IRR_OFFSET6:
+       case IRR_OFFSET7:
+       case ISR_OFFSET0:
+       case ISR_OFFSET1:
+       case ISR_OFFSET2:
+       case ISR_OFFSET3:
+       case ISR_OFFSET4:
+       case ISR_OFFSET5:
+       case ISR_OFFSET6:
+       case ISR_OFFSET7:
+       case TRIG_OFFSET0:
+       case TRIG_OFFSET1:
+       case TRIG_OFFSET2:
+       case TRIG_OFFSET3:
+       case TRIG_OFFSET4:
+       case TRIG_OFFSET5:
+       case TRIG_OFFSET6:
+       case TRIG_OFFSET7:
+       case PPR_OFFSET:
+       case EXT_APIC_FEATURE_OFFSET:
+
+           PrintError("apic %u: core %u: Attempting to write to read only register %p (error)\n", 
+                      apic->lapic_id.val, core->cpu_id, (void *)reg_addr);
+           //  goto apic_write_out_bad;
+
+           break;
+
+           // Data registers
+       case APIC_ID_OFFSET:
+           //V3_Print("apic %u: core %u: my id is being changed to %u\n", 
+           //       apic->lapic_id.val, core->cpu_id, op_val);
+
+           apic->lapic_id.val = op_val;
+           break;
+       case TPR_OFFSET:
+           apic->task_prio.val = op_val;
+           break;
+       case LDR_OFFSET:
+           PrintDebug("apic %u: core %u: setting log_dst.val to 0x%x\n",
+                      apic->lapic_id.val, core->cpu_id, op_val);
+           apic->log_dst.val = op_val;
+           break;
+       case DFR_OFFSET:
+           apic->dst_fmt.val = op_val;
+           break;
+       case SPURIOUS_INT_VEC_OFFSET:
+           apic->spurious_int.val = op_val;
+           break;
+       case ESR_OFFSET:
+           apic->err_status.val = op_val;
+           break;
+       case TMR_LOC_VEC_TBL_OFFSET:
+           apic->tmr_vec_tbl.val = op_val;
+           break;
+       case THERM_LOC_VEC_TBL_OFFSET:
+           apic->therm_loc_vec_tbl.val = op_val;
+           break;
+       case PERF_CTR_LOC_VEC_TBL_OFFSET:
+           apic->perf_ctr_loc_vec_tbl.val = op_val;
+           break;
+       case LINT0_VEC_TBL_OFFSET:
+           apic->lint0_vec_tbl.val = op_val;
+           break;
+       case LINT1_VEC_TBL_OFFSET:
+           apic->lint1_vec_tbl.val = op_val;
+           break;
+       case ERR_VEC_TBL_OFFSET:
+           apic->err_vec_tbl.val = op_val;
+           break;
+       case TMR_INIT_CNT_OFFSET:
+           apic->tmr_init_cnt = op_val;
+           apic->tmr_cur_cnt = op_val;
+           break;
+       case TMR_CUR_CNT_OFFSET:
+           apic->tmr_cur_cnt = op_val;
+           break;
+       case TMR_DIV_CFG_OFFSET:
+           apic->tmr_div_cfg.val = op_val;
+           break;
+
+
+           // Enable mask (256 bits)
+       case IER_OFFSET0:
+           *(uint32_t *)(apic->int_en_reg) = op_val;
+           break;
+       case IER_OFFSET1:
+           *(uint32_t *)(apic->int_en_reg + 4) = op_val;
+           break;
+       case IER_OFFSET2:
+           *(uint32_t *)(apic->int_en_reg + 8) = op_val;
+           break;
+       case IER_OFFSET3:
+           *(uint32_t *)(apic->int_en_reg + 12) = op_val;
+           break;
+       case IER_OFFSET4:
+           *(uint32_t *)(apic->int_en_reg + 16) = op_val;
+           break;
+       case IER_OFFSET5:
+           *(uint32_t *)(apic->int_en_reg + 20) = op_val;
+           break;
+       case IER_OFFSET6:
+           *(uint32_t *)(apic->int_en_reg + 24) = op_val;
+           break;
+       case IER_OFFSET7:
+           *(uint32_t *)(apic->int_en_reg + 28) = op_val;
+           break;
+
+       case EXT_INT_LOC_VEC_TBL_OFFSET0:
+           apic->ext_intr_vec_tbl[0].val = op_val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET1:
+           apic->ext_intr_vec_tbl[1].val = op_val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET2:
+           apic->ext_intr_vec_tbl[2].val = op_val;
+           break;
+       case EXT_INT_LOC_VEC_TBL_OFFSET3:
+           apic->ext_intr_vec_tbl[3].val = op_val;
+           break;
+
+
+           // Action Registers
+       case EOI_OFFSET:
+           // do eoi (we already have the lock)
+           apic_do_eoi(apic);
+           break;
+
+       case INT_CMD_LO_OFFSET: {
+           // execute command (we already have the lock)
+
+           struct int_cmd_reg tmp_icr;
+
+           apic->int_cmd.lo = op_val;
+
+           tmp_icr=apic->int_cmd;
+
+           //      V3_Print("apic %u: core %u: sending cmd 0x%llx to apic %u\n", 
+           //       apic->lapic_id.val, core->cpu_id,
+           //       apic->int_cmd.val, apic->int_cmd.dst);
+
+           apic->in_icr=0;
+
+           v3_unlock(apic->lock);
+
+           // route_ipi is responsible for locking apics, so we go in unlocked)
+           if (route_ipi(apic_dev, apic, &tmp_icr) == -1) { 
+               PrintError("IPI Routing failure\n");
+               goto apic_write_out_bad;
+           }
+
+           //      v3_lock(apic->lock);  // expected for leaving this function
+
+       }
+           break;
 
-  PrintDebug("Write finished\n");
+       case INT_CMD_HI_OFFSET: {
+           // already have the lock
+           if (apic->in_icr) { 
+               PrintError("apic %u: core %u: writing command high=0x%x while in_icr=1\n", apic->lapic_id.val, core->cpu_id,apic->int_cmd.hi);
+           }
+
+           apic->int_cmd.hi = op_val;
+           //V3_Print("apic %u: core %u: writing command high=0x%x\n", apic->lapic_id.val, core->cpu_id,apic->int_cmd.hi);
+           apic->in_icr=1;
+       }
+           break;
 
-  return length;
+
+       // Unhandled Registers
+       case EXT_APIC_CMD_OFFSET:
+       case SEOI_OFFSET:
+       default:
+           PrintError("apic %u: core %u: Write to Unhandled APIC Register: %x (ignored)\n", 
+                      apic->lapic_id.val, core->cpu_id, (uint32_t)reg_addr);
+
+           goto apic_write_out_bad;
+    }
+
+    PrintDebug("apic %u: core %u: Write finished\n", apic->lapic_id.val, core->cpu_id);
+
+    // apic_write_out_good:
+    v3_unlock(apic->lock);
+    return length;
+
+ apic_write_out_bad:
+    v3_unlock(apic->lock);
+    return -1;
 }
 
 
 
 /* Interrupt Controller Functions */
 
-static int apic_intr_pending(void * private_data) {
-  struct vm_device * dev = (struct vm_device *)private_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  int i = 0;
+// internally used, expects caller to lock
+static int apic_intr_pending_nolock(struct guest_info * core, void * private_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int req_irq = get_highest_irr(apic);
+    int svc_irq = get_highest_isr(apic);
 
+    //    PrintDebug("apic %u: core %u: req_irq=%d, svc_irq=%d\n",apic->lapic_id.val,info->cpu_id,req_irq,svc_irq);
 
-  // just scan the request register looking for any set bit
-  // we should probably just do this with uint64 casts 
-  for (i = 0; i < 32; i++) {
-    if (apic->int_req_reg[i] & 0xff) {
-      return 1;
+    if ((req_irq >= 0) && 
+       (req_irq > svc_irq)) {
+       return 1;
     }
-  }
-  return 0;
-}
 
-static int apic_get_intr_number(void * private_data) {
-  struct vm_device * dev = (struct vm_device *)private_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  int i = 0, j = 0;
+    return 0;
+}
 
+// externally visible, so must lock itself
+static int apic_intr_pending(struct guest_info * core, void * private_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int rc;
 
-  // We iterate backwards to find the highest priority
-  for (i = 31; i >= 0; i--) {
-    uchar_t req_major = apic->int_req_reg[i];
+    v3_lock(apic->lock);
     
-    if (req_major & 0xff) {
-      for (j = 7; j >= 0; j--) {
-       if ((req_major >> j) == 0x1) {
-         return (i * 8) + j;
-       }
-      }
+    rc=apic_intr_pending_nolock(core,private_data);
+    
+    v3_unlock(apic->lock);
+
+    return rc;
+}
+
+// Internal - no lock
+static int apic_get_intr_number_nolock(struct guest_info * core, void * private_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int req_irq = get_highest_irr(apic);
+    int svc_irq = get_highest_isr(apic);
+
+    if (svc_irq == -1) {
+       return req_irq;
+    } else if (svc_irq < req_irq) {
+       return req_irq;
     }
-  }
 
-  return -1;
+    return -1;
 }
 
-static int apic_raise_intr(void * private_data, int irq) {
-  return 0;
+
+// Externally visible, so must lock itself
+static int apic_get_intr_number(struct guest_info * core, void * private_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int rc;
+
+    v3_lock(apic->lock);
+    
+    rc=apic_get_intr_number_nolock(core,private_data);
+
+    v3_unlock(apic->lock);
+
+    return rc;
 }
 
-static int apic_lower_intr(void * private_data, int irq) {
-  return 0;
+
+//
+// Here there is no source APIC, so there is no need to lock it
+// Furthermore, the expectation is that route_ipi will lock the destiation apic
+int v3_apic_send_ipi(struct v3_vm_info * vm, struct v3_gen_ipi * ipi, void * dev_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)
+       (((struct vm_device *)dev_data)->private_data);
+    struct int_cmd_reg tmp_icr;
+
+    // zero out all the fields
+    tmp_icr.val = 0;
+
+    tmp_icr.vec = ipi->vector;
+    tmp_icr.del_mode = ipi->mode;
+    tmp_icr.dst_mode = ipi->logical;
+    tmp_icr.trig_mode = ipi->trigger_mode;
+    tmp_icr.dst_shorthand = ipi->dst_shorthand;
+    tmp_icr.dst = ipi->dst;
+
+    // route_ipi is responsible for locking the destination apic
+    return route_ipi(apic_dev, NULL, &tmp_icr);
 }
 
-static int apic_begin_irq(void * private_data, int irq) {
-  struct vm_device * dev = (struct vm_device *)private_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  int major_offset = (irq & ~0x00000007) >> 3;
-  int minor_offset = irq & 0x00000007;
-  uchar_t * req_location = apic->int_req_reg + major_offset;
-  uchar_t * svc_location = apic->int_svc_reg + major_offset;
-  uchar_t flag = 0x01 << minor_offset;
 
-  *svc_location |= flag;
-  *req_location &= ~flag;
+int v3_apic_raise_intr(struct v3_vm_info * vm, uint32_t irq, uint32_t dst, void * dev_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)
+       (((struct vm_device*)dev_data)->private_data);
+    struct apic_state * apic = &(apic_dev->apics[dst]); 
+    int do_xcall;
 
-  return 0;
+    PrintDebug("apic %u core ?: raising interrupt IRQ %u (dst = %u).\n", apic->lapic_id.val, irq, dst); 
+
+    v3_lock(apic->lock);
+
+    do_xcall=activate_apic_irq_nolock(apic, irq);
+
+    if (do_xcall<0) { 
+       PrintError("Failed to activate apic irq\n");
+       v3_unlock(apic->lock);
+       return -1;
+    }
+    
+    if (do_xcall>0 && (V3_Get_CPU() != dst)) {
+#ifdef CONFIG_MULTITHREAD_OS
+       v3_interrupt_cpu(vm, dst, 0);
+#else
+       V3_ASSERT(0);
+#endif
+
+    }
+    v3_unlock(apic->lock);
+    return 0;
 }
 
 
+// internal - caller must lock
+static int apic_begin_irq_nolock(struct guest_info * core, void * private_data, int irq) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int major_offset = (irq & ~0x00000007) >> 3;
+    int minor_offset = irq & 0x00000007;
+    uint8_t *req_location = apic->int_req_reg + major_offset;
+    uint8_t *svc_location = apic->int_svc_reg + major_offset;
+    uint8_t flag = 0x01 << minor_offset;
+
+    if (*req_location & flag) {
+       // we will only pay attention to a begin irq if we
+       // know that we initiated it!
+       *svc_location |= flag;
+       *req_location &= ~flag;
+    } else {
+       // do nothing... 
+       //PrintDebug("apic %u: core %u: begin irq for %d ignored since I don't own it\n",
+       //         apic->lapic_id.val, core->cpu_id, irq);
+    }
 
-int v3_apic_raise_intr(struct vm_device * apic_dev, int intr_num) {
-  struct apic_state * apic = (struct apic_state *)apic_dev->private_data;
-  return activate_apic_irq(apic, intr_num);
+    return 0;
+}
+
+// Since this is called, externally, it should lock the apic
+static int apic_begin_irq(struct guest_info * core, void * private_data, int irq) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(private_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+    int rc;
+
+    v3_lock(apic->lock);
+
+    rc=apic_begin_irq_nolock(core,private_data,irq);
+
+    v3_unlock(apic->lock);
+
+    return rc;
 }
 
 
 
 /* Timer Functions */
-static void apic_update_time(ullong_t cpu_cycles, ullong_t cpu_freq, void * priv_data) {
-  struct vm_device * dev = (struct vm_device *)priv_data;
-  struct apic_state * apic = (struct apic_state *)dev->private_data;
-  // The 32 bit GCC runtime is a pile of shit
+// Caller will lock the apic
+static void apic_update_time_nolock(struct guest_info * core, 
+                            uint64_t cpu_cycles, uint64_t cpu_freq, 
+                            void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(priv_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+
+    // The 32 bit GCC runtime is a pile of shit
 #ifdef __V3_64BIT__
-  uint64_t tmr_ticks = 0;
+    uint64_t tmr_ticks = 0;
 #else 
-  uint32_t tmr_ticks = 0;
+    uint32_t tmr_ticks = 0;
 #endif
 
-  uchar_t tmr_div = *(uchar_t *)&(apic->tmr_div_cfg.val);
-  uint_t shift_num = 0;
+    uint8_t tmr_div = *(uint8_t *)&(apic->tmr_div_cfg.val);
+    uint_t shift_num = 0;
 
 
-  // Check whether this is true:
-  //   -> If the Init count is zero then the timer is disabled
-  //      and doesn't just blitz interrupts to the CPU
-  if ((apic->tmr_init_cnt == 0) || 
-      ( (apic->tmr_vec_tbl.tmr_mode == APIC_TMR_ONESHOT) &&
-       (apic->tmr_cur_cnt == 0))) {
-    //PrintDebug("APIC timer not yet initialized\n");
-    return;
-  }
+    // Check whether this is true:
+    //   -> If the Init count is zero then the timer is disabled
+    //      and doesn't just blitz interrupts to the CPU
+    if ((apic->tmr_init_cnt == 0) || 
+       ( (apic->tmr_vec_tbl.tmr_mode == APIC_TMR_ONESHOT) &&
+         (apic->tmr_cur_cnt == 0))) {
+       //PrintDebug("apic %u: core %u: APIC timer not yet initialized\n",apic->lapic_id.val,info->cpu_id);
+       return;
+    }
 
 
-  switch (tmr_div) {
-  case APIC_TMR_DIV1:
-    shift_num = 0;
-    break;
-  case APIC_TMR_DIV2:
-    shift_num = 1;
-    break;
-  case APIC_TMR_DIV4:
-    shift_num = 2;
-    break;
-  case APIC_TMR_DIV8:
-    shift_num = 3;
-    break;
-  case APIC_TMR_DIV16:
-    shift_num = 4;
-    break;
-  case APIC_TMR_DIV32:
-    shift_num = 5;
-    break;
-  case APIC_TMR_DIV64:
-    shift_num = 6;
-    break;
- case APIC_TMR_DIV128:
-    shift_num = 7;
-    break;
-  default:
-    PrintError("Invalid Timer Divider configuration\n");
-    return;
-  }
+    switch (tmr_div) {
+       case APIC_TMR_DIV1:
+           shift_num = 0;
+           break;
+       case APIC_TMR_DIV2:
+           shift_num = 1;
+           break;
+       case APIC_TMR_DIV4:
+           shift_num = 2;
+           break;
+       case APIC_TMR_DIV8:
+           shift_num = 3;
+           break;
+       case APIC_TMR_DIV16:
+           shift_num = 4;
+           break;
+       case APIC_TMR_DIV32:
+           shift_num = 5;
+           break;
+       case APIC_TMR_DIV64:
+           shift_num = 6;
+           break;
+       case APIC_TMR_DIV128:
+           shift_num = 7;
+           break;
+       default:
+           PrintError("apic %u: core %u: Invalid Timer Divider configuration\n",
+                      apic->lapic_id.val, core->cpu_id);
+           return;
+    }
 
-  tmr_ticks = cpu_cycles >> shift_num;
-  //  PrintDebug("Timer Ticks: %p\n", (void *)tmr_ticks);
+    tmr_ticks = cpu_cycles >> shift_num;
+    //    PrintDebug("Timer Ticks: %p\n", (void *)tmr_ticks);
 
-  if (tmr_ticks < apic->tmr_cur_cnt) {
-    apic->tmr_cur_cnt -= tmr_ticks;
-  } else {
-    tmr_ticks -= apic->tmr_cur_cnt;
-    apic->tmr_cur_cnt = 0;
+    if (tmr_ticks < apic->tmr_cur_cnt) {
+       apic->tmr_cur_cnt -= tmr_ticks;
+    } else {
+       tmr_ticks -= apic->tmr_cur_cnt;
+       apic->tmr_cur_cnt = 0;
 
-    // raise irq
-    PrintDebug("Raising APIC Timer interrupt (periodic=%d) (icnt=%d) (div=%d)\n", 
-              apic->tmr_vec_tbl.tmr_mode, apic->tmr_init_cnt, shift_num);
-    if (activate_internal_irq(apic, APIC_TMR_INT) == -1) {
-      PrintError("Could not raise Timer interrupt\n");
-    }
+       // raise irq
+       PrintDebug("apic %u: core %u: Raising APIC Timer interrupt (periodic=%d) (icnt=%d) (div=%d)\n",
+                  apic->lapic_id.val, core->cpu_id,
+                  apic->tmr_vec_tbl.tmr_mode, apic->tmr_init_cnt, shift_num);
+
+       if (apic_intr_pending_nolock(core, priv_data)) {
+           PrintDebug("apic %u: core %u: Overriding pending IRQ %d\n", 
+                      apic->lapic_id.val, core->cpu_id, 
+                      apic_get_intr_number(core, priv_data));
+       }
+
+       if (activate_internal_irq_nolock(apic, APIC_TMR_INT) == -1) {
+           PrintError("apic %u: core %u: Could not raise Timer interrupt\n",
+                      apic->lapic_id.val, core->cpu_id);
+       }
     
-    if (apic->tmr_vec_tbl.tmr_mode == APIC_TMR_PERIODIC) {
-      tmr_ticks = tmr_ticks % apic->tmr_init_cnt;
-      apic->tmr_cur_cnt = apic->tmr_init_cnt - tmr_ticks;
+       if (apic->tmr_vec_tbl.tmr_mode == APIC_TMR_PERIODIC) {
+           tmr_ticks = tmr_ticks % apic->tmr_init_cnt;
+           apic->tmr_cur_cnt = apic->tmr_init_cnt - tmr_ticks;
+       }
     }
-  }
-
 
+    return;
 }
 
 
+static void apic_update_time(struct guest_info * core, 
+                            uint64_t cpu_cycles, uint64_t cpu_freq, 
+                            void * priv_data) {
+    struct apic_dev_state * apic_dev = (struct apic_dev_state *)(priv_data);
+    struct apic_state * apic = &(apic_dev->apics[core->cpu_id]); 
+
+    v3_lock(apic->lock);
+
+    apic_update_time_nolock(core,cpu_cycles,cpu_freq,priv_data);
+
+    v3_unlock(apic->lock);
+    
+    return;
+}
 
 static struct intr_ctrl_ops intr_ops = {
-  .intr_pending = apic_intr_pending,
-  .get_intr_number = apic_get_intr_number,
-  .raise_intr = apic_raise_intr,
-  .begin_irq = apic_begin_irq,
-  .lower_intr = apic_lower_intr, 
+    .intr_pending = apic_intr_pending,
+    .get_intr_number = apic_get_intr_number,
+    .begin_irq = apic_begin_irq,
 };
 
 
-static struct vm_timer_ops timer_ops = {
-  .update_time = apic_update_time,
+static struct v3_timer_ops timer_ops = {
+    .update_timer = apic_update_time,
 };
 
 
-static int apic_init(struct vm_device * dev) {
-  struct guest_info * info = dev->vm;
-  struct apic_state * apic = (struct apic_state *)(dev->private_data);
 
-  v3_register_intr_controller(dev->vm, &intr_ops, dev);
-  v3_add_timer(dev->vm, &timer_ops, dev);
 
-  init_apic_state(apic);
+static int apic_free(struct apic_dev_state * apic_dev) {
+    int i = 0;
+    struct v3_vm_info * vm = NULL;
 
-  v3_hook_msr(info, BASE_ADDR_MSR, read_apic_msr, write_apic_msr, dev);
+    for (i = 0; i < apic_dev->num_apics; i++) {
+       struct apic_state * apic = &(apic_dev->apics[i]);
+       struct guest_info * core = apic->core;
+       
+       vm = core->vm_info;
 
-  v3_hook_full_mem(info, apic->base_addr, apic->base_addr + PAGE_SIZE_4KB, apic_read, apic_write, dev);
+       v3_remove_intr_controller(core, apic->controller_handle);
 
-  return 0;
-}
+       if (apic->timer) {
+           v3_remove_timer(core, apic->timer);
+       }
 
-static int apic_deinit(struct vm_device * dev) {
-  struct guest_info * info = dev->vm;
+       // unhook memory
 
-  v3_unhook_msr(info, BASE_ADDR_MSR);
+    }
 
-  return 0;
+    v3_unhook_msr(vm, BASE_ADDR_MSR);
+
+    V3_Free(apic_dev);
+    return 0;
 }
 
 
-static struct vm_device_ops dev_ops = {
-  .init = apic_init,
-  .deinit = apic_deinit,
-  .reset = NULL,
-  .start = NULL,
-  .stop = NULL,
+static struct v3_device_ops dev_ops = {
+    .free = (int (*)(void *))apic_free,
 };
 
 
-struct vm_device * v3_create_apic() {
-  PrintDebug("Creating APIC\n");
 
-  struct apic_state * apic = (struct apic_state *)V3_Malloc(sizeof(struct apic_state));
+static int apic_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
+    char * dev_id = v3_cfg_val(cfg, "ID");
+    struct apic_dev_state * apic_dev = NULL;
+    int i = 0;
 
-  struct vm_device * device = v3_create_device("APIC", &dev_ops, apic);
-  
-  return device;
+    PrintDebug("apic: creating an APIC for each core\n");
+
+    apic_dev = (struct apic_dev_state *)V3_Malloc(sizeof(struct apic_dev_state) + 
+                                                 sizeof(struct apic_state) * vm->num_cores);
+
+    apic_dev->num_apics = vm->num_cores;
+
+    //v3_lock_init(&(apic_dev->ipi_lock));
+
+    struct vm_device * dev = v3_add_device(vm, dev_id, &dev_ops, apic_dev);
+
+    if (dev == NULL) {
+       PrintError("apic: Could not attach device %s\n", dev_id);
+       V3_Free(apic_dev);
+       return -1;
+    }
+
+    
+    for (i = 0; i < vm->num_cores; i++) {
+       struct apic_state * apic = &(apic_dev->apics[i]);
+       struct guest_info * core = &(vm->cores[i]);
+
+       apic->core = core;
+
+       init_apic_state(apic, i);
+
+       apic->controller_handle = v3_register_intr_controller(core, &intr_ops, apic_dev);
+
+       apic->timer = v3_add_timer(core, &timer_ops, apic_dev);
+
+       if (apic->timer == NULL) {
+           PrintError("APIC: Failed to attach timer to core %d\n", i);
+           v3_remove_device(dev);
+           return -1;
+       }
+
+       v3_hook_full_mem(vm, core->cpu_id, apic->base_addr, apic->base_addr + PAGE_SIZE_4KB, apic_read, apic_write, apic_dev);
+
+       PrintDebug("apic %u: (setup device): done, my id is %u\n", i, apic->lapic_id.val);
+    }
+
+#ifdef CONFIG_DEBUG_APIC
+    for (i = 0; i < vm->num_cores; i++) {
+       struct apic_state * apic = &(apic_dev->apics[i]);
+       PrintDebug("apic: sanity check: apic %u (at %p) has id %u and msr value %llx and core at %p\n",
+                  i, apic, apic->lapic_id.val, apic->base_addr_msr.value,apic->core);
+    }
+#endif
+
+
+    PrintDebug("apic: priv_data is at %p\n", apic_dev);
+
+    v3_hook_msr(vm, BASE_ADDR_MSR, read_apic_msr, write_apic_msr, apic_dev);
+
+    return 0;
 }
+
+
+
+device_register("LAPIC", apic_init)