hw/xen/xen-hvm-common.c - third_party/qemu - Git at Google

 #include "qemu/osdep.h"
 #include "qemu/units.h"
 #include "qapi/error.h"
 #include "exec/target_page.h"
 #include "trace.h"

 #include "hw/pci/pci_host.h"
 #include "hw/xen/xen-hvm-common.h"
 #include "hw/xen/xen-bus.h"
 #include "hw/boards.h"
 #include "hw/xen/arch_hvm.h"

 MemoryRegion xen_memory;

 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
                    Error **errp)
 {
     unsigned target_page_bits = qemu_target_page_bits();
     unsigned long nr_pfn;
     xen_pfn_t *pfn_list;
     int i;

     if (runstate_check(RUN_STATE_INMIGRATE)) {
         /* RAM already populated in Xen */
         warn_report("%s: do not alloc "RAM_ADDR_FMT
                 " bytes of ram at "RAM_ADDR_FMT" when runstate is INMIGRATE",
                 __func__, size, ram_addr);
         return;
     }

     if (mr == &xen_memory) {
         return;
     }

     trace_xen_ram_alloc(ram_addr, size);

     nr_pfn = size >> target_page_bits;
     pfn_list = g_new(xen_pfn_t, nr_pfn);

     for (i = 0; i < nr_pfn; i++) {
         pfn_list[i] = (ram_addr >> target_page_bits) + i;
     }

     if (xc_domain_populate_physmap_exact(xen_xc, xen_domid, nr_pfn, 0, 0, pfn_list)) {
         error_setg(errp, "xen: failed to populate ram at " RAM_ADDR_FMT,
                    ram_addr);
     }

     g_free(pfn_list);
 }

 static void xen_set_memory(struct MemoryListener *listener,
                            MemoryRegionSection *section,
                            bool add)
 {
     XenIOState *state = container_of(listener, XenIOState, memory_listener);

     if (section->mr == &xen_memory) {
         return;
     } else {
         if (add) {
             xen_map_memory_section(xen_domid, state->ioservid,
                                    section);
         } else {
             xen_unmap_memory_section(xen_domid, state->ioservid,
                                      section);
         }
     }

     arch_xen_set_memory(state, section, add);
 }

 void xen_region_add(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
     memory_region_ref(section->mr);
     xen_set_memory(listener, section, true);
 }

 void xen_region_del(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
     xen_set_memory(listener, section, false);
     memory_region_unref(section->mr);
 }

 void xen_io_add(MemoryListener *listener,
                        MemoryRegionSection *section)
 {
     XenIOState *state = container_of(listener, XenIOState, io_listener);
     MemoryRegion *mr = section->mr;

     if (mr->ops == &unassigned_io_ops) {
         return;
     }

     memory_region_ref(mr);

     xen_map_io_section(xen_domid, state->ioservid, section);
 }

 void xen_io_del(MemoryListener *listener,
                        MemoryRegionSection *section)
 {
     XenIOState *state = container_of(listener, XenIOState, io_listener);
     MemoryRegion *mr = section->mr;

     if (mr->ops == &unassigned_io_ops) {
         return;
     }

     xen_unmap_io_section(xen_domid, state->ioservid, section);

     memory_region_unref(mr);
 }

 void xen_device_realize(DeviceListener *listener,
                                DeviceState *dev)
 {
     XenIOState *state = container_of(listener, XenIOState, device_listener);

     if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         PCIDevice *pci_dev = PCI_DEVICE(dev);
         XenPciDevice *xendev = g_new(XenPciDevice, 1);

         xendev->pci_dev = pci_dev;
         xendev->sbdf = PCI_BUILD_BDF(pci_dev_bus_num(pci_dev),
                                      pci_dev->devfn);
         QLIST_INSERT_HEAD(&state->dev_list, xendev, entry);

         xen_map_pcidev(xen_domid, state->ioservid, pci_dev);
     }
 }

 void xen_device_unrealize(DeviceListener *listener,
                                  DeviceState *dev)
 {
     XenIOState *state = container_of(listener, XenIOState, device_listener);

     if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         PCIDevice *pci_dev = PCI_DEVICE(dev);
         XenPciDevice *xendev, *next;

         xen_unmap_pcidev(xen_domid, state->ioservid, pci_dev);

         QLIST_FOREACH_SAFE(xendev, &state->dev_list, entry, next) {
             if (xendev->pci_dev == pci_dev) {
                 QLIST_REMOVE(xendev, entry);
                 g_free(xendev);
                 break;
             }
         }
     }
 }

 MemoryListener xen_io_listener = {
     .name = "xen-io",
     .region_add = xen_io_add,
     .region_del = xen_io_del,
     .priority = MEMORY_LISTENER_PRIORITY_ACCEL,
 };

 DeviceListener xen_device_listener = {
     .realize = xen_device_realize,
     .unrealize = xen_device_unrealize,
 };

 /* get the ioreq packets from share mem */
 static ioreq_t *cpu_get_ioreq_from_shared_memory(XenIOState *state, int vcpu)
 {
     ioreq_t *req = xen_vcpu_ioreq(state->shared_page, vcpu);

     if (req->state != STATE_IOREQ_READY) {
         trace_cpu_get_ioreq_from_shared_memory_req_not_ready(req->state,
                                                              req->data_is_ptr,
                                                              req->addr,
                                                              req->data,
                                                              req->count,
                                                              req->size);
         return NULL;
     }

     xen_rmb(); /* see IOREQ_READY /then/ read contents of ioreq */

     req->state = STATE_IOREQ_INPROCESS;
     return req;
 }

 /* use poll to get the port notification */
 /* ioreq_vec--out,the */
 /* retval--the number of ioreq packet */
 static ioreq_t *cpu_get_ioreq(XenIOState *state)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
     unsigned int max_cpus = ms->smp.max_cpus;
     int i;
     evtchn_port_t port;

     port = qemu_xen_evtchn_pending(state->xce_handle);
     if (port == state->bufioreq_local_port) {
         timer_mod(state->buffered_io_timer,
                 BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
         return NULL;
     }

     if (port != -1) {
         for (i = 0; i < max_cpus; i++) {
             if (state->ioreq_local_port[i] == port) {
                 break;
             }
         }

         if (i == max_cpus) {
             hw_error("Fatal error while trying to get io event!\n");
         }

         /* unmask the wanted port again */
         qemu_xen_evtchn_unmask(state->xce_handle, port);

         /* get the io packet from shared memory */
         state->send_vcpu = i;
         return cpu_get_ioreq_from_shared_memory(state, i);
     }

     /* read error or read nothing */
     return NULL;
 }

 static uint32_t do_inp(uint32_t addr, unsigned long size)
 {
     switch (size) {
         case 1:
             return cpu_inb(addr);
         case 2:
             return cpu_inw(addr);
         case 4:
             return cpu_inl(addr);
         default:
             hw_error("inp: bad size: %04x %lx", addr, size);
     }
 }

 static void do_outp(uint32_t addr,
         unsigned long size, uint32_t val)
 {
     switch (size) {
         case 1:
             return cpu_outb(addr, val);
         case 2:
             return cpu_outw(addr, val);
         case 4:
             return cpu_outl(addr, val);
         default:
             hw_error("outp: bad size: %04x %lx", addr, size);
     }
 }

 /*
  * Helper functions which read/write an object from/to physical guest
  * memory, as part of the implementation of an ioreq.
  *
  * Equivalent to
  *   cpu_physical_memory_rw(addr + (req->df ? -1 : +1) * req->size * i,
  *                          val, req->size, 0/1)
  * except without the integer overflow problems.
  */
 static void rw_phys_req_item(hwaddr addr,
                              ioreq_t *req, uint32_t i, void *val, int rw)
 {
     /* Do everything unsigned so overflow just results in a truncated result
      * and accesses to undesired parts of guest memory, which is up
      * to the guest */
     hwaddr offset = (hwaddr)req->size * i;
     if (req->df) {
         addr -= offset;
     } else {
         addr += offset;
     }
     cpu_physical_memory_rw(addr, val, req->size, rw);
 }

 static inline void read_phys_req_item(hwaddr addr,
                                       ioreq_t *req, uint32_t i, void *val)
 {
     rw_phys_req_item(addr, req, i, val, 0);
 }
 static inline void write_phys_req_item(hwaddr addr,
                                        ioreq_t *req, uint32_t i, void *val)
 {
     rw_phys_req_item(addr, req, i, val, 1);
 }


 void cpu_ioreq_pio(ioreq_t *req)
 {
     uint32_t i;

     trace_cpu_ioreq_pio(req, req->dir, req->df, req->data_is_ptr, req->addr,
                          req->data, req->count, req->size);

     if (req->size > sizeof(uint32_t)) {
         hw_error("PIO: bad size (%u)", req->size);
     }

     if (req->dir == IOREQ_READ) {
         if (!req->data_is_ptr) {
             req->data = do_inp(req->addr, req->size);
             trace_cpu_ioreq_pio_read_reg(req, req->data, req->addr,
                                          req->size);
         } else {
             uint32_t tmp;

             for (i = 0; i < req->count; i++) {
                 tmp = do_inp(req->addr, req->size);
                 write_phys_req_item(req->data, req, i, &tmp);
             }
         }
     } else if (req->dir == IOREQ_WRITE) {
         if (!req->data_is_ptr) {
             trace_cpu_ioreq_pio_write_reg(req, req->data, req->addr,
                                           req->size);
             do_outp(req->addr, req->size, req->data);
         } else {
             for (i = 0; i < req->count; i++) {
                 uint32_t tmp = 0;

                 read_phys_req_item(req->data, req, i, &tmp);
                 do_outp(req->addr, req->size, tmp);
             }
         }
     }
 }

 static void cpu_ioreq_move(ioreq_t *req)
 {
     uint32_t i;

     trace_cpu_ioreq_move(req, req->dir, req->df, req->data_is_ptr, req->addr,
                          req->data, req->count, req->size);

     if (req->size > sizeof(req->data)) {
         hw_error("MMIO: bad size (%u)", req->size);
     }

     if (!req->data_is_ptr) {
         if (req->dir == IOREQ_READ) {
             for (i = 0; i < req->count; i++) {
                 read_phys_req_item(req->addr, req, i, &req->data);
             }
         } else if (req->dir == IOREQ_WRITE) {
             for (i = 0; i < req->count; i++) {
                 write_phys_req_item(req->addr, req, i, &req->data);
             }
         }
     } else {
         uint64_t tmp;

         if (req->dir == IOREQ_READ) {
             for (i = 0; i < req->count; i++) {
                 read_phys_req_item(req->addr, req, i, &tmp);
                 write_phys_req_item(req->data, req, i, &tmp);
             }
         } else if (req->dir == IOREQ_WRITE) {
             for (i = 0; i < req->count; i++) {
                 read_phys_req_item(req->data, req, i, &tmp);
                 write_phys_req_item(req->addr, req, i, &tmp);
             }
         }
     }
 }

 static void cpu_ioreq_config(XenIOState *state, ioreq_t *req)
 {
     uint32_t sbdf = req->addr >> 32;
     uint32_t reg = req->addr;
     XenPciDevice *xendev;

     if (req->size != sizeof(uint8_t) && req->size != sizeof(uint16_t) &&
         req->size != sizeof(uint32_t)) {
         hw_error("PCI config access: bad size (%u)", req->size);
     }

     if (req->count != 1) {
         hw_error("PCI config access: bad count (%u)", req->count);
     }

     QLIST_FOREACH(xendev, &state->dev_list, entry) {
         if (xendev->sbdf != sbdf) {
             continue;
         }

         if (!req->data_is_ptr) {
             if (req->dir == IOREQ_READ) {
                 req->data = pci_host_config_read_common(
                     xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
                     req->size);
                 trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
                                             req->size, req->data);
             } else if (req->dir == IOREQ_WRITE) {
                 trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
                                              req->size, req->data);
                 pci_host_config_write_common(
                     xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
                     req->data, req->size);
             }
         } else {
             uint32_t tmp;

             if (req->dir == IOREQ_READ) {
                 tmp = pci_host_config_read_common(
                     xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
                     req->size);
                 trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
                                             req->size, tmp);
                 write_phys_req_item(req->data, req, 0, &tmp);
             } else if (req->dir == IOREQ_WRITE) {
                 read_phys_req_item(req->data, req, 0, &tmp);
                 trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
                                              req->size, tmp);
                 pci_host_config_write_common(
                     xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
                     tmp, req->size);
             }
         }
     }
 }

 static void handle_ioreq(XenIOState *state, ioreq_t *req)
 {
     trace_handle_ioreq(req, req->type, req->dir, req->df, req->data_is_ptr,
                        req->addr, req->data, req->count, req->size);

     if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
             (req->size < sizeof (target_ulong))) {
         req->data &= ((target_ulong) 1 << (8 * req->size)) - 1;
     }

     if (req->dir == IOREQ_WRITE)
         trace_handle_ioreq_write(req, req->type, req->df, req->data_is_ptr,
                                  req->addr, req->data, req->count, req->size);

     switch (req->type) {
         case IOREQ_TYPE_PIO:
             cpu_ioreq_pio(req);
             break;
         case IOREQ_TYPE_COPY:
             cpu_ioreq_move(req);
             break;
         case IOREQ_TYPE_TIMEOFFSET:
             break;
         case IOREQ_TYPE_INVALIDATE:
             xen_invalidate_map_cache();
             break;
         case IOREQ_TYPE_PCI_CONFIG:
             cpu_ioreq_config(state, req);
             break;
         default:
             arch_handle_ioreq(state, req);
     }
     if (req->dir == IOREQ_READ) {
         trace_handle_ioreq_read(req, req->type, req->df, req->data_is_ptr,
                                 req->addr, req->data, req->count, req->size);
     }
 }

 static bool handle_buffered_iopage(XenIOState *state)
 {
     buffered_iopage_t *buf_page = state->buffered_io_page;
     buf_ioreq_t *buf_req = NULL;
     bool handled_ioreq = false;
     ioreq_t req;
     int qw;

     if (!buf_page) {
         return 0;
     }

     memset(&req, 0x00, sizeof(req));
     req.state = STATE_IOREQ_READY;
     req.count = 1;
     req.dir = IOREQ_WRITE;

     for (;;) {
         uint32_t rdptr = buf_page->read_pointer, wrptr;

         xen_rmb();
         wrptr = buf_page->write_pointer;
         xen_rmb();
         if (rdptr != buf_page->read_pointer) {
             continue;
         }
         if (rdptr == wrptr) {
             break;
         }
         buf_req = &buf_page->buf_ioreq[rdptr % IOREQ_BUFFER_SLOT_NUM];
         req.size = 1U << buf_req->size;
         req.addr = buf_req->addr;
         req.data = buf_req->data;
         req.type = buf_req->type;
         xen_rmb();
         qw = (req.size == 8);
         if (qw) {
             if (rdptr + 1 == wrptr) {
                 hw_error("Incomplete quad word buffered ioreq");
             }
             buf_req = &buf_page->buf_ioreq[(rdptr + 1) %
                                            IOREQ_BUFFER_SLOT_NUM];
             req.data |= ((uint64_t)buf_req->data) << 32;
             xen_rmb();
         }

         handle_ioreq(state, &req);

         /* Only req.data may get updated by handle_ioreq(), albeit even that
          * should not happen as such data would never make it to the guest (we
          * can only usefully see writes here after all).
          */
         assert(req.state == STATE_IOREQ_READY);
         assert(req.count == 1);
         assert(req.dir == IOREQ_WRITE);
         assert(!req.data_is_ptr);

         qatomic_add(&buf_page->read_pointer, qw + 1);
         handled_ioreq = true;
     }

     return handled_ioreq;
 }

 static void handle_buffered_io(void *opaque)
 {
     XenIOState *state = opaque;

     if (handle_buffered_iopage(state)) {
         timer_mod(state->buffered_io_timer,
                 BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
     } else {
         timer_del(state->buffered_io_timer);
         qemu_xen_evtchn_unmask(state->xce_handle, state->bufioreq_local_port);
     }
 }

 static void cpu_handle_ioreq(void *opaque)
 {
     XenIOState *state = opaque;
     ioreq_t *req = cpu_get_ioreq(state);

     handle_buffered_iopage(state);
     if (req) {
         ioreq_t copy = *req;

         xen_rmb();
         handle_ioreq(state, &copy);
         req->data = copy.data;

         if (req->state != STATE_IOREQ_INPROCESS) {
             warn_report("Badness in I/O request ... not in service?!: "
                     "%x, ptr: %x, port: %"PRIx64", "
                     "data: %"PRIx64", count: %u, size: %u, type: %u",
                     req->state, req->data_is_ptr, req->addr,
                     req->data, req->count, req->size, req->type);
             destroy_hvm_domain(false);
             return;
         }

         xen_wmb(); /* Update ioreq contents /then/ update state. */

         /*
          * We do this before we send the response so that the tools
          * have the opportunity to pick up on the reset before the
          * guest resumes and does a hlt with interrupts disabled which
          * causes Xen to powerdown the domain.
          */
         if (runstate_is_running()) {
             ShutdownCause request;

             if (qemu_shutdown_requested_get()) {
                 destroy_hvm_domain(false);
             }
             request = qemu_reset_requested_get();
             if (request) {
                 qemu_system_reset(request);
                 destroy_hvm_domain(true);
             }
         }

         req->state = STATE_IORESP_READY;
         qemu_xen_evtchn_notify(state->xce_handle,
                                state->ioreq_local_port[state->send_vcpu]);
     }
 }

 static void xen_main_loop_prepare(XenIOState *state)
 {
     int evtchn_fd = -1;

     if (state->xce_handle != NULL) {
         evtchn_fd = qemu_xen_evtchn_fd(state->xce_handle);
     }

     state->buffered_io_timer = timer_new_ms(QEMU_CLOCK_REALTIME, handle_buffered_io,
                                                  state);

     if (evtchn_fd != -1) {
         CPUState *cpu_state;

         CPU_FOREACH(cpu_state) {
             trace_xen_main_loop_prepare_init_cpu(cpu_state->cpu_index,
                                                  cpu_state);
             state->cpu_by_vcpu_id[cpu_state->cpu_index] = cpu_state;
         }
         qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state);
     }
 }


 void xen_hvm_change_state_handler(void *opaque, bool running,
                                          RunState rstate)
 {
     XenIOState *state = opaque;

     if (running) {
         xen_main_loop_prepare(state);
     }

     xen_set_ioreq_server_state(xen_domid,
                                state->ioservid,
                                running);
 }

 void xen_exit_notifier(Notifier *n, void *data)
 {
     XenIOState *state = container_of(n, XenIOState, exit);

     xen_destroy_ioreq_server(xen_domid, state->ioservid);
     if (state->fres != NULL) {
         xenforeignmemory_unmap_resource(xen_fmem, state->fres);
     }

     qemu_xen_evtchn_close(state->xce_handle);
     xs_daemon_close(state->xenstore);
 }

 static int xen_map_ioreq_server(XenIOState *state)
 {
     void *addr = NULL;
     xen_pfn_t ioreq_pfn;
     xen_pfn_t bufioreq_pfn;
     evtchn_port_t bufioreq_evtchn;
     int rc;

     /*
      * Attempt to map using the resource API and fall back to normal
      * foreign mapping if this is not supported.
      */
     QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_bufioreq != 0);
     QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_ioreq(0) != 1);
     state->fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
                                          XENMEM_resource_ioreq_server,
                                          state->ioservid, 0, 2,
                                          &addr,
                                          PROT_READ | PROT_WRITE, 0);
     if (state->fres != NULL) {
         trace_xen_map_resource_ioreq(state->ioservid, addr);
         state->buffered_io_page = addr;
         state->shared_page = addr + XC_PAGE_SIZE;
     } else if (errno != EOPNOTSUPP) {
         error_report("failed to map ioreq server resources: error %d handle=%p",
                      errno, xen_xc);
         return -1;
     }

     rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
                                    (state->shared_page == NULL) ?
                                    &ioreq_pfn : NULL,
                                    (state->buffered_io_page == NULL) ?
                                    &bufioreq_pfn : NULL,
                                    &bufioreq_evtchn);
     if (rc < 0) {
         error_report("failed to get ioreq server info: error %d handle=%p",
                      errno, xen_xc);
         return rc;
     }

     if (state->shared_page == NULL) {
         trace_xen_map_ioreq_server_shared_page(ioreq_pfn);

         state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
                                                   PROT_READ | PROT_WRITE,
                                                   1, &ioreq_pfn, NULL);
         if (state->shared_page == NULL) {
             error_report("map shared IO page returned error %d handle=%p",
                          errno, xen_xc);
         }
     }

     if (state->buffered_io_page == NULL) {
         trace_xen_map_ioreq_server_buffered_io_page(bufioreq_pfn);

         state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
                                                        PROT_READ | PROT_WRITE,
                                                        1, &bufioreq_pfn,
                                                        NULL);
         if (state->buffered_io_page == NULL) {
             error_report("map buffered IO page returned error %d", errno);
             return -1;
         }
     }

     if (state->shared_page == NULL || state->buffered_io_page == NULL) {
         return -1;
     }

     trace_xen_map_ioreq_server_buffered_io_evtchn(bufioreq_evtchn);

     state->bufioreq_remote_port = bufioreq_evtchn;

     return 0;
 }

 void destroy_hvm_domain(bool reboot)
 {
     xc_interface *xc_handle;
     int sts;
     int rc;

     unsigned int reason = reboot ? SHUTDOWN_reboot : SHUTDOWN_poweroff;

     if (xen_dmod) {
         rc = xendevicemodel_shutdown(xen_dmod, xen_domid, reason);
         if (!rc) {
             return;
         }
         if (errno != ENOTTY /* old Xen */) {
             error_report("xendevicemodel_shutdown failed with error %d", errno);
         }
         /* well, try the old thing then */
     }

     xc_handle = xc_interface_open(0, 0, 0);
     if (xc_handle == NULL) {
         trace_destroy_hvm_domain_cannot_acquire_handle();
     } else {
         sts = xc_domain_shutdown(xc_handle, xen_domid, reason);
         if (sts != 0) {
             trace_destroy_hvm_domain_failed_action(
                 reboot ? "reboot" : "poweroff", sts, strerror(errno)
             );
         } else {
             trace_destroy_hvm_domain_action(
                 xen_domid, reboot ? "reboot" : "poweroff"
             );
         }
         xc_interface_close(xc_handle);
     }
 }

 void xen_shutdown_fatal_error(const char *fmt, ...)
 {
     va_list ap;

     va_start(ap, fmt);
     error_vreport(fmt, ap);
     va_end(ap);
     error_report("Will destroy the domain.");
     /* destroy the domain */
     qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_ERROR);
 }

 static void xen_do_ioreq_register(XenIOState *state,
                                   unsigned int max_cpus,
                                   const MemoryListener *xen_memory_listener)
 {
     int i, rc;

     state->exit.notify = xen_exit_notifier;
     qemu_add_exit_notifier(&state->exit);

     /*
      * Register wake-up support in QMP query-current-machine API
      */
     qemu_register_wakeup_support();

     rc = xen_map_ioreq_server(state);
     if (rc < 0) {
         goto err;
     }

     /* Note: cpus is empty at this point in init */
     state->cpu_by_vcpu_id = g_new0(CPUState *, max_cpus);

     rc = xen_set_ioreq_server_state(xen_domid, state->ioservid, true);
     if (rc < 0) {
         error_report("failed to enable ioreq server info: error %d handle=%p",
                      errno, xen_xc);
         goto err;
     }

     state->ioreq_local_port = g_new0(evtchn_port_t, max_cpus);

     /* FIXME: how about if we overflow the page here? */
     for (i = 0; i < max_cpus; i++) {
         rc = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
                                               xen_vcpu_eport(state->shared_page,
                                                              i));
         if (rc == -1) {
             error_report("shared evtchn %d bind error %d", i, errno);
             goto err;
         }
         state->ioreq_local_port[i] = rc;
     }

     rc = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
                                           state->bufioreq_remote_port);
     if (rc == -1) {
         error_report("buffered evtchn bind error %d", errno);
         goto err;
     }
     state->bufioreq_local_port = rc;

     /* Init RAM management */
 #ifdef XEN_COMPAT_PHYSMAP
     xen_map_cache_init(xen_phys_offset_to_gaddr, state);
 #else
     xen_map_cache_init(NULL, state);
 #endif

     qemu_add_vm_change_state_handler(xen_hvm_change_state_handler, state);

     state->memory_listener = *xen_memory_listener;
     memory_listener_register(&state->memory_listener, &address_space_memory);

     state->io_listener = xen_io_listener;
     memory_listener_register(&state->io_listener, &address_space_io);

     state->device_listener = xen_device_listener;
     QLIST_INIT(&state->dev_list);
     device_listener_register(&state->device_listener);

     return;

 err:
     error_report("xen hardware virtual machine initialisation failed");
     exit(1);
 }

 void xen_register_ioreq(XenIOState *state, unsigned int max_cpus,
                         const MemoryListener *xen_memory_listener)
 {
     int rc;

     setup_xen_backend_ops();

     state->xce_handle = qemu_xen_evtchn_open();
     if (state->xce_handle == NULL) {
         error_report("xen: event channel open failed with error %d", errno);
         goto err;
     }

     state->xenstore = xs_daemon_open();
     if (state->xenstore == NULL) {
         error_report("xen: xenstore open failed with error %d", errno);
         goto err;
     }

     rc = xen_create_ioreq_server(xen_domid, &state->ioservid);
     if (!rc) {
         xen_do_ioreq_register(state, max_cpus, xen_memory_listener);
     } else {
         warn_report("xen: failed to create ioreq server");
     }

     xen_bus_init();

     return;

 err:
     error_report("xen hardware virtual machine backend registration failed");
     exit(1);
 }
	#include "qemu/osdep.h"
	#include "qemu/units.h"
	#include "qapi/error.h"
	#include "exec/target_page.h"
	#include "trace.h"

	#include "hw/pci/pci_host.h"
	#include "hw/xen/xen-hvm-common.h"
	#include "hw/xen/xen-bus.h"
	#include "hw/boards.h"
	#include "hw/xen/arch_hvm.h"

	MemoryRegion xen_memory;

	void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
	Error **errp)
	{
	unsigned target_page_bits = qemu_target_page_bits();
	unsigned long nr_pfn;
	xen_pfn_t *pfn_list;
	int i;

	if (runstate_check(RUN_STATE_INMIGRATE)) {
	/* RAM already populated in Xen */
	warn_report("%s: do not alloc "RAM_ADDR_FMT
	" bytes of ram at "RAM_ADDR_FMT" when runstate is INMIGRATE",
	__func__, size, ram_addr);
	return;
	}

	if (mr == &xen_memory) {
	return;
	}

	trace_xen_ram_alloc(ram_addr, size);

	nr_pfn = size >> target_page_bits;
	pfn_list = g_new(xen_pfn_t, nr_pfn);

	for (i = 0; i < nr_pfn; i++) {
	pfn_list[i] = (ram_addr >> target_page_bits) + i;
	}

	if (xc_domain_populate_physmap_exact(xen_xc, xen_domid, nr_pfn, 0, 0, pfn_list)) {
	error_setg(errp, "xen: failed to populate ram at " RAM_ADDR_FMT,
	ram_addr);
	}

	g_free(pfn_list);
	}

	static void xen_set_memory(struct MemoryListener *listener,
	MemoryRegionSection *section,
	bool add)
	{
	XenIOState *state = container_of(listener, XenIOState, memory_listener);

	if (section->mr == &xen_memory) {
	return;
	} else {
	if (add) {
	xen_map_memory_section(xen_domid, state->ioservid,
	section);
	} else {
	xen_unmap_memory_section(xen_domid, state->ioservid,
	section);
	}
	}

	arch_xen_set_memory(state, section, add);
	}

	void xen_region_add(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	memory_region_ref(section->mr);
	xen_set_memory(listener, section, true);
	}

	void xen_region_del(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	xen_set_memory(listener, section, false);
	memory_region_unref(section->mr);
	}

	void xen_io_add(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	XenIOState *state = container_of(listener, XenIOState, io_listener);
	MemoryRegion *mr = section->mr;

	if (mr->ops == &unassigned_io_ops) {
	return;
	}

	memory_region_ref(mr);

	xen_map_io_section(xen_domid, state->ioservid, section);
	}

	void xen_io_del(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	XenIOState *state = container_of(listener, XenIOState, io_listener);
	MemoryRegion *mr = section->mr;

	if (mr->ops == &unassigned_io_ops) {
	return;
	}

	xen_unmap_io_section(xen_domid, state->ioservid, section);

	memory_region_unref(mr);
	}

	void xen_device_realize(DeviceListener *listener,
	DeviceState *dev)
	{
	XenIOState *state = container_of(listener, XenIOState, device_listener);

	if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
	PCIDevice *pci_dev = PCI_DEVICE(dev);
	XenPciDevice *xendev = g_new(XenPciDevice, 1);

	xendev->pci_dev = pci_dev;
	xendev->sbdf = PCI_BUILD_BDF(pci_dev_bus_num(pci_dev),
	pci_dev->devfn);
	QLIST_INSERT_HEAD(&state->dev_list, xendev, entry);

	xen_map_pcidev(xen_domid, state->ioservid, pci_dev);
	}
	}

	void xen_device_unrealize(DeviceListener *listener,
	DeviceState *dev)
	{
	XenIOState *state = container_of(listener, XenIOState, device_listener);

	if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
	PCIDevice *pci_dev = PCI_DEVICE(dev);
	XenPciDevice xendev, next;

	xen_unmap_pcidev(xen_domid, state->ioservid, pci_dev);

	QLIST_FOREACH_SAFE(xendev, &state->dev_list, entry, next) {
	if (xendev->pci_dev == pci_dev) {
	QLIST_REMOVE(xendev, entry);
	g_free(xendev);
	break;
	}
	}
	}
	}

	MemoryListener xen_io_listener = {
	.name = "xen-io",
	.region_add = xen_io_add,
	.region_del = xen_io_del,
	.priority = MEMORY_LISTENER_PRIORITY_ACCEL,
	};

	DeviceListener xen_device_listener = {
	.realize = xen_device_realize,
	.unrealize = xen_device_unrealize,
	};

	/* get the ioreq packets from share mem */
	static ioreq_t cpu_get_ioreq_from_shared_memory(XenIOState state, int vcpu)
	{
	ioreq_t *req = xen_vcpu_ioreq(state->shared_page, vcpu);

	if (req->state != STATE_IOREQ_READY) {
	trace_cpu_get_ioreq_from_shared_memory_req_not_ready(req->state,
	req->data_is_ptr,
	req->addr,
	req->data,
	req->count,
	req->size);
	return NULL;
	}

	xen_rmb(); /* see IOREQ_READY /then/ read contents of ioreq */

	req->state = STATE_IOREQ_INPROCESS;
	return req;
	}

	/* use poll to get the port notification */
	/* ioreq_vec--out,the */
	/* retval--the number of ioreq packet */
	static ioreq_t cpu_get_ioreq(XenIOState state)
	{
	MachineState *ms = MACHINE(qdev_get_machine());
	unsigned int max_cpus = ms->smp.max_cpus;
	int i;
	evtchn_port_t port;

	port = qemu_xen_evtchn_pending(state->xce_handle);
	if (port == state->bufioreq_local_port) {
	timer_mod(state->buffered_io_timer,
	BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
	return NULL;
	}

	if (port != -1) {
	for (i = 0; i < max_cpus; i++) {
	if (state->ioreq_local_port[i] == port) {
	break;
	}
	}

	if (i == max_cpus) {
	hw_error("Fatal error while trying to get io event!\n");
	}

	/* unmask the wanted port again */
	qemu_xen_evtchn_unmask(state->xce_handle, port);

	/* get the io packet from shared memory */
	state->send_vcpu = i;
	return cpu_get_ioreq_from_shared_memory(state, i);
	}

	/* read error or read nothing */
	return NULL;
	}

	static uint32_t do_inp(uint32_t addr, unsigned long size)
	{
	switch (size) {
	case 1:
	return cpu_inb(addr);
	case 2:
	return cpu_inw(addr);
	case 4:
	return cpu_inl(addr);
	default:
	hw_error("inp: bad size: %04x %lx", addr, size);
	}
	}

	static void do_outp(uint32_t addr,
	unsigned long size, uint32_t val)
	{
	switch (size) {
	case 1:
	return cpu_outb(addr, val);
	case 2:
	return cpu_outw(addr, val);
	case 4:
	return cpu_outl(addr, val);
	default:
	hw_error("outp: bad size: %04x %lx", addr, size);
	}
	}

	/*
	* Helper functions which read/write an object from/to physical guest
	* memory, as part of the implementation of an ioreq.
	*
	* Equivalent to
	* cpu_physical_memory_rw(addr + (req->df ? -1 : +1) * req->size * i,
	* val, req->size, 0/1)
	* except without the integer overflow problems.
	*/
	static void rw_phys_req_item(hwaddr addr,
	ioreq_t req, uint32_t i, void val, int rw)
	{
	/* Do everything unsigned so overflow just results in a truncated result
	* and accesses to undesired parts of guest memory, which is up
	* to the guest */
	hwaddr offset = (hwaddr)req->size * i;
	if (req->df) {
	addr -= offset;
	} else {
	addr += offset;
	}
	cpu_physical_memory_rw(addr, val, req->size, rw);
	}

	static inline void read_phys_req_item(hwaddr addr,
	ioreq_t req, uint32_t i, void val)
	{
	rw_phys_req_item(addr, req, i, val, 0);
	}
	static inline void write_phys_req_item(hwaddr addr,
	ioreq_t req, uint32_t i, void val)
	{
	rw_phys_req_item(addr, req, i, val, 1);
	}


	void cpu_ioreq_pio(ioreq_t *req)
	{
	uint32_t i;

	trace_cpu_ioreq_pio(req, req->dir, req->df, req->data_is_ptr, req->addr,
	req->data, req->count, req->size);

	if (req->size > sizeof(uint32_t)) {
	hw_error("PIO: bad size (%u)", req->size);
	}

	if (req->dir == IOREQ_READ) {
	if (!req->data_is_ptr) {
	req->data = do_inp(req->addr, req->size);
	trace_cpu_ioreq_pio_read_reg(req, req->data, req->addr,
	req->size);
	} else {
	uint32_t tmp;

	for (i = 0; i < req->count; i++) {
	tmp = do_inp(req->addr, req->size);
	write_phys_req_item(req->data, req, i, &tmp);
	}
	}
	} else if (req->dir == IOREQ_WRITE) {
	if (!req->data_is_ptr) {
	trace_cpu_ioreq_pio_write_reg(req, req->data, req->addr,
	req->size);
	do_outp(req->addr, req->size, req->data);
	} else {
	for (i = 0; i < req->count; i++) {
	uint32_t tmp = 0;

	read_phys_req_item(req->data, req, i, &tmp);
	do_outp(req->addr, req->size, tmp);
	}
	}
	}
	}

	static void cpu_ioreq_move(ioreq_t *req)
	{
	uint32_t i;

	trace_cpu_ioreq_move(req, req->dir, req->df, req->data_is_ptr, req->addr,
	req->data, req->count, req->size);

	if (req->size > sizeof(req->data)) {
	hw_error("MMIO: bad size (%u)", req->size);
	}

	if (!req->data_is_ptr) {
	if (req->dir == IOREQ_READ) {
	for (i = 0; i < req->count; i++) {
	read_phys_req_item(req->addr, req, i, &req->data);
	}
	} else if (req->dir == IOREQ_WRITE) {
	for (i = 0; i < req->count; i++) {
	write_phys_req_item(req->addr, req, i, &req->data);
	}
	}
	} else {
	uint64_t tmp;

	if (req->dir == IOREQ_READ) {
	for (i = 0; i < req->count; i++) {
	read_phys_req_item(req->addr, req, i, &tmp);
	write_phys_req_item(req->data, req, i, &tmp);
	}
	} else if (req->dir == IOREQ_WRITE) {
	for (i = 0; i < req->count; i++) {
	read_phys_req_item(req->data, req, i, &tmp);
	write_phys_req_item(req->addr, req, i, &tmp);
	}
	}
	}
	}

	static void cpu_ioreq_config(XenIOState state, ioreq_t req)
	{
	uint32_t sbdf = req->addr >> 32;
	uint32_t reg = req->addr;
	XenPciDevice *xendev;

	if (req->size != sizeof(uint8_t) && req->size != sizeof(uint16_t) &&
	req->size != sizeof(uint32_t)) {
	hw_error("PCI config access: bad size (%u)", req->size);
	}

	if (req->count != 1) {
	hw_error("PCI config access: bad count (%u)", req->count);
	}

	QLIST_FOREACH(xendev, &state->dev_list, entry) {
	if (xendev->sbdf != sbdf) {
	continue;
	}

	if (!req->data_is_ptr) {
	if (req->dir == IOREQ_READ) {
	req->data = pci_host_config_read_common(
	xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
	req->size);
	trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
	req->size, req->data);
	} else if (req->dir == IOREQ_WRITE) {
	trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
	req->size, req->data);
	pci_host_config_write_common(
	xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
	req->data, req->size);
	}
	} else {
	uint32_t tmp;

	if (req->dir == IOREQ_READ) {
	tmp = pci_host_config_read_common(
	xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
	req->size);
	trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
	req->size, tmp);
	write_phys_req_item(req->data, req, 0, &tmp);
	} else if (req->dir == IOREQ_WRITE) {
	read_phys_req_item(req->data, req, 0, &tmp);
	trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
	req->size, tmp);
	pci_host_config_write_common(
	xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
	tmp, req->size);
	}
	}
	}
	}

	static void handle_ioreq(XenIOState state, ioreq_t req)
	{
	trace_handle_ioreq(req, req->type, req->dir, req->df, req->data_is_ptr,
	req->addr, req->data, req->count, req->size);

	if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
	(req->size < sizeof (target_ulong))) {
	req->data &= ((target_ulong) 1 << (8 * req->size)) - 1;
	}

	if (req->dir == IOREQ_WRITE)
	trace_handle_ioreq_write(req, req->type, req->df, req->data_is_ptr,
	req->addr, req->data, req->count, req->size);

	switch (req->type) {
	case IOREQ_TYPE_PIO:
	cpu_ioreq_pio(req);
	break;
	case IOREQ_TYPE_COPY:
	cpu_ioreq_move(req);
	break;
	case IOREQ_TYPE_TIMEOFFSET:
	break;
	case IOREQ_TYPE_INVALIDATE:
	xen_invalidate_map_cache();
	break;
	case IOREQ_TYPE_PCI_CONFIG:
	cpu_ioreq_config(state, req);
	break;
	default:
	arch_handle_ioreq(state, req);
	}
	if (req->dir == IOREQ_READ) {
	trace_handle_ioreq_read(req, req->type, req->df, req->data_is_ptr,
	req->addr, req->data, req->count, req->size);
	}
	}

	static bool handle_buffered_iopage(XenIOState *state)
	{
	buffered_iopage_t *buf_page = state->buffered_io_page;
	buf_ioreq_t *buf_req = NULL;
	bool handled_ioreq = false;
	ioreq_t req;
	int qw;

	if (!buf_page) {
	return 0;
	}

	memset(&req, 0x00, sizeof(req));
	req.state = STATE_IOREQ_READY;
	req.count = 1;
	req.dir = IOREQ_WRITE;

	for (;;) {
	uint32_t rdptr = buf_page->read_pointer, wrptr;

	xen_rmb();
	wrptr = buf_page->write_pointer;
	xen_rmb();
	if (rdptr != buf_page->read_pointer) {
	continue;
	}
	if (rdptr == wrptr) {
	break;
	}
	buf_req = &buf_page->buf_ioreq[rdptr % IOREQ_BUFFER_SLOT_NUM];
	req.size = 1U << buf_req->size;
	req.addr = buf_req->addr;
	req.data = buf_req->data;
	req.type = buf_req->type;
	xen_rmb();
	qw = (req.size == 8);
	if (qw) {
	if (rdptr + 1 == wrptr) {
	hw_error("Incomplete quad word buffered ioreq");
	}
	buf_req = &buf_page->buf_ioreq[(rdptr + 1) %
	IOREQ_BUFFER_SLOT_NUM];
	req.data \|= ((uint64_t)buf_req->data) << 32;
	xen_rmb();
	}

	handle_ioreq(state, &req);

	/* Only req.data may get updated by handle_ioreq(), albeit even that
	* should not happen as such data would never make it to the guest (we
	* can only usefully see writes here after all).
	*/
	assert(req.state == STATE_IOREQ_READY);
	assert(req.count == 1);
	assert(req.dir == IOREQ_WRITE);
	assert(!req.data_is_ptr);

	qatomic_add(&buf_page->read_pointer, qw + 1);
	handled_ioreq = true;
	}

	return handled_ioreq;
	}

	static void handle_buffered_io(void *opaque)
	{
	XenIOState *state = opaque;

	if (handle_buffered_iopage(state)) {
	timer_mod(state->buffered_io_timer,
	BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
	} else {
	timer_del(state->buffered_io_timer);
	qemu_xen_evtchn_unmask(state->xce_handle, state->bufioreq_local_port);
	}
	}

	static void cpu_handle_ioreq(void *opaque)
	{
	XenIOState *state = opaque;
	ioreq_t *req = cpu_get_ioreq(state);

	handle_buffered_iopage(state);
	if (req) {
	ioreq_t copy = *req;

	xen_rmb();
	handle_ioreq(state, &copy);
	req->data = copy.data;

	if (req->state != STATE_IOREQ_INPROCESS) {
	warn_report("Badness in I/O request ... not in service?!: "
	"%x, ptr: %x, port: %"PRIx64", "
	"data: %"PRIx64", count: %u, size: %u, type: %u",
	req->state, req->data_is_ptr, req->addr,
	req->data, req->count, req->size, req->type);
	destroy_hvm_domain(false);
	return;
	}

	xen_wmb(); /* Update ioreq contents /then/ update state. */

	/*
	* We do this before we send the response so that the tools
	* have the opportunity to pick up on the reset before the
	* guest resumes and does a hlt with interrupts disabled which
	* causes Xen to powerdown the domain.
	*/
	if (runstate_is_running()) {
	ShutdownCause request;

	if (qemu_shutdown_requested_get()) {
	destroy_hvm_domain(false);
	}
	request = qemu_reset_requested_get();
	if (request) {
	qemu_system_reset(request);
	destroy_hvm_domain(true);
	}
	}

	req->state = STATE_IORESP_READY;
	qemu_xen_evtchn_notify(state->xce_handle,
	state->ioreq_local_port[state->send_vcpu]);
	}
	}

	static void xen_main_loop_prepare(XenIOState *state)
	{
	int evtchn_fd = -1;

	if (state->xce_handle != NULL) {
	evtchn_fd = qemu_xen_evtchn_fd(state->xce_handle);
	}

	state->buffered_io_timer = timer_new_ms(QEMU_CLOCK_REALTIME, handle_buffered_io,
	state);

	if (evtchn_fd != -1) {
	CPUState *cpu_state;

	CPU_FOREACH(cpu_state) {
	trace_xen_main_loop_prepare_init_cpu(cpu_state->cpu_index,
	cpu_state);
	state->cpu_by_vcpu_id[cpu_state->cpu_index] = cpu_state;
	}
	qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state);
	}
	}


	void xen_hvm_change_state_handler(void *opaque, bool running,
	RunState rstate)
	{
	XenIOState *state = opaque;

	if (running) {
	xen_main_loop_prepare(state);
	}

	xen_set_ioreq_server_state(xen_domid,
	state->ioservid,
	running);
	}

	void xen_exit_notifier(Notifier n, void data)
	{
	XenIOState *state = container_of(n, XenIOState, exit);

	xen_destroy_ioreq_server(xen_domid, state->ioservid);
	if (state->fres != NULL) {
	xenforeignmemory_unmap_resource(xen_fmem, state->fres);
	}

	qemu_xen_evtchn_close(state->xce_handle);
	xs_daemon_close(state->xenstore);
	}

	static int xen_map_ioreq_server(XenIOState *state)
	{
	void *addr = NULL;
	xen_pfn_t ioreq_pfn;
	xen_pfn_t bufioreq_pfn;
	evtchn_port_t bufioreq_evtchn;
	int rc;

	/*
	* Attempt to map using the resource API and fall back to normal
	* foreign mapping if this is not supported.
	*/
	QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_bufioreq != 0);
	QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_ioreq(0) != 1);
	state->fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
	XENMEM_resource_ioreq_server,
	state->ioservid, 0, 2,
	&addr,
	PROT_READ \| PROT_WRITE, 0);
	if (state->fres != NULL) {
	trace_xen_map_resource_ioreq(state->ioservid, addr);
	state->buffered_io_page = addr;
	state->shared_page = addr + XC_PAGE_SIZE;
	} else if (errno != EOPNOTSUPP) {
	error_report("failed to map ioreq server resources: error %d handle=%p",
	errno, xen_xc);
	return -1;
	}

	rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
	(state->shared_page == NULL) ?
	&ioreq_pfn : NULL,
	(state->buffered_io_page == NULL) ?
	&bufioreq_pfn : NULL,
	&bufioreq_evtchn);
	if (rc < 0) {
	error_report("failed to get ioreq server info: error %d handle=%p",
	errno, xen_xc);
	return rc;
	}

	if (state->shared_page == NULL) {
	trace_xen_map_ioreq_server_shared_page(ioreq_pfn);

	state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
	PROT_READ \| PROT_WRITE,
	1, &ioreq_pfn, NULL);
	if (state->shared_page == NULL) {
	error_report("map shared IO page returned error %d handle=%p",
	errno, xen_xc);
	}
	}

	if (state->buffered_io_page == NULL) {
	trace_xen_map_ioreq_server_buffered_io_page(bufioreq_pfn);

	state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
	PROT_READ \| PROT_WRITE,
	1, &bufioreq_pfn,
	NULL);
	if (state->buffered_io_page == NULL) {
	error_report("map buffered IO page returned error %d", errno);
	return -1;
	}
	}

	if (state->shared_page == NULL \|\| state->buffered_io_page == NULL) {
	return -1;
	}

	trace_xen_map_ioreq_server_buffered_io_evtchn(bufioreq_evtchn);

	state->bufioreq_remote_port = bufioreq_evtchn;

	return 0;
	}

	void destroy_hvm_domain(bool reboot)
	{
	xc_interface *xc_handle;
	int sts;
	int rc;

	unsigned int reason = reboot ? SHUTDOWN_reboot : SHUTDOWN_poweroff;

	if (xen_dmod) {
	rc = xendevicemodel_shutdown(xen_dmod, xen_domid, reason);
	if (!rc) {
	return;
	}
	if (errno != ENOTTY /* old Xen */) {
	error_report("xendevicemodel_shutdown failed with error %d", errno);
	}
	/* well, try the old thing then */
	}

	xc_handle = xc_interface_open(0, 0, 0);
	if (xc_handle == NULL) {
	trace_destroy_hvm_domain_cannot_acquire_handle();
	} else {
	sts = xc_domain_shutdown(xc_handle, xen_domid, reason);
	if (sts != 0) {
	trace_destroy_hvm_domain_failed_action(
	reboot ? "reboot" : "poweroff", sts, strerror(errno)
	);
	} else {
	trace_destroy_hvm_domain_action(
	xen_domid, reboot ? "reboot" : "poweroff"
	);
	}
	xc_interface_close(xc_handle);
	}
	}

	void xen_shutdown_fatal_error(const char *fmt, ...)
	{
	va_list ap;

	va_start(ap, fmt);
	error_vreport(fmt, ap);
	va_end(ap);
	error_report("Will destroy the domain.");
	/* destroy the domain */
	qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_ERROR);
	}

	static void xen_do_ioreq_register(XenIOState *state,
	unsigned int max_cpus,
	const MemoryListener *xen_memory_listener)
	{
	int i, rc;

	state->exit.notify = xen_exit_notifier;
	qemu_add_exit_notifier(&state->exit);

	/*
	* Register wake-up support in QMP query-current-machine API
	*/
	qemu_register_wakeup_support();

	rc = xen_map_ioreq_server(state);
	if (rc < 0) {
	goto err;
	}

	/* Note: cpus is empty at this point in init */
	state->cpu_by_vcpu_id = g_new0(CPUState *, max_cpus);

	rc = xen_set_ioreq_server_state(xen_domid, state->ioservid, true);
	if (rc < 0) {
	error_report("failed to enable ioreq server info: error %d handle=%p",
	errno, xen_xc);
	goto err;
	}

	state->ioreq_local_port = g_new0(evtchn_port_t, max_cpus);

	/* FIXME: how about if we overflow the page here? */
	for (i = 0; i < max_cpus; i++) {
	rc = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
	xen_vcpu_eport(state->shared_page,
	i));
	if (rc == -1) {
	error_report("shared evtchn %d bind error %d", i, errno);
	goto err;
	}
	state->ioreq_local_port[i] = rc;
	}

	rc = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
	state->bufioreq_remote_port);
	if (rc == -1) {
	error_report("buffered evtchn bind error %d", errno);
	goto err;
	}
	state->bufioreq_local_port = rc;

	/* Init RAM management */
	#ifdef XEN_COMPAT_PHYSMAP
	xen_map_cache_init(xen_phys_offset_to_gaddr, state);
	#else
	xen_map_cache_init(NULL, state);
	#endif

	qemu_add_vm_change_state_handler(xen_hvm_change_state_handler, state);

	state->memory_listener = *xen_memory_listener;
	memory_listener_register(&state->memory_listener, &address_space_memory);

	state->io_listener = xen_io_listener;
	memory_listener_register(&state->io_listener, &address_space_io);

	state->device_listener = xen_device_listener;
	QLIST_INIT(&state->dev_list);
	device_listener_register(&state->device_listener);

	return;

	err:
	error_report("xen hardware virtual machine initialisation failed");
	exit(1);
	}

	void xen_register_ioreq(XenIOState *state, unsigned int max_cpus,
	const MemoryListener *xen_memory_listener)
	{
	int rc;

	setup_xen_backend_ops();

	state->xce_handle = qemu_xen_evtchn_open();
	if (state->xce_handle == NULL) {
	error_report("xen: event channel open failed with error %d", errno);
	goto err;
	}

	state->xenstore = xs_daemon_open();
	if (state->xenstore == NULL) {
	error_report("xen: xenstore open failed with error %d", errno);
	goto err;
	}

	rc = xen_create_ioreq_server(xen_domid, &state->ioservid);
	if (!rc) {
	xen_do_ioreq_register(state, max_cpus, xen_memory_listener);
	} else {
	warn_report("xen: failed to create ioreq server");
	}

	xen_bus_init();

	return;

	err:
	error_report("xen hardware virtual machine backend registration failed");
	exit(1);
	}