accel/hvf/hvf-accel-ops.c - qemu - Git at Google

 /*
  * Copyright 2008 IBM Corporation
  *           2008 Red Hat, Inc.
  * Copyright 2011 Intel Corporation
  * Copyright 2016 Veertu, Inc.
  * Copyright 2017 The Android Open Source Project
  *
  * QEMU Hypervisor.framework support
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  *
  * This file contain code under public domain from the hvdos project:
  * https://github.com/mist64/hvdos
  *
  * Parts Copyright (c) 2011 NetApp, Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "exec/address-spaces.h"
 #include "exec/exec-all.h"
 #include "exec/gdbstub.h"
 #include "sysemu/cpus.h"
 #include "sysemu/hvf.h"
 #include "sysemu/hvf_int.h"
 #include "sysemu/runstate.h"
 #include "qemu/guest-random.h"

 HVFState *hvf_state;

 #ifdef __aarch64__
 #define HV_VM_DEFAULT NULL
 #endif

 /* Memory slots */

 hvf_slot *hvf_find_overlap_slot(uint64_t start, uint64_t size)
 {
     hvf_slot *slot;
     int x;
     for (x = 0; x < hvf_state->num_slots; ++x) {
         slot = &hvf_state->slots[x];
         if (slot->size && start < (slot->start + slot->size) &&
             (start + size) > slot->start) {
             return slot;
         }
     }
     return NULL;
 }

 struct mac_slot {
     int present;
     uint64_t size;
     uint64_t gpa_start;
     uint64_t gva;
 };

 struct mac_slot mac_slots[32];

 static int do_hvf_set_memory(hvf_slot *slot, hv_memory_flags_t flags)
 {
     struct mac_slot *macslot;
     hv_return_t ret;

     macslot = &mac_slots[slot->slot_id];

     if (macslot->present) {
         if (macslot->size != slot->size) {
             macslot->present = 0;
             ret = hv_vm_unmap(macslot->gpa_start, macslot->size);
             assert_hvf_ok(ret);
         }
     }

     if (!slot->size) {
         return 0;
     }

     macslot->present = 1;
     macslot->gpa_start = slot->start;
     macslot->size = slot->size;
     ret = hv_vm_map(slot->mem, slot->start, slot->size, flags);
     assert_hvf_ok(ret);
     return 0;
 }

 static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
 {
     hvf_slot *mem;
     MemoryRegion *area = section->mr;
     bool writable = !area->readonly && !area->rom_device;
     hv_memory_flags_t flags;
     uint64_t page_size = qemu_real_host_page_size();

     if (!memory_region_is_ram(area)) {
         if (writable) {
             return;
         } else if (!memory_region_is_romd(area)) {
             /*
              * If the memory device is not in romd_mode, then we actually want
              * to remove the hvf memory slot so all accesses will trap.
              */
              add = false;
         }
     }

     if (!QEMU_IS_ALIGNED(int128_get64(section->size), page_size) ||
         !QEMU_IS_ALIGNED(section->offset_within_address_space, page_size)) {
         /* Not page aligned, so we can not map as RAM */
         add = false;
     }

     mem = hvf_find_overlap_slot(
             section->offset_within_address_space,
             int128_get64(section->size));

     if (mem && add) {
         if (mem->size == int128_get64(section->size) &&
             mem->start == section->offset_within_address_space &&
             mem->mem == (memory_region_get_ram_ptr(area) +
             section->offset_within_region)) {
             return; /* Same region was attempted to register, go away. */
         }
     }

     /* Region needs to be reset. set the size to 0 and remap it. */
     if (mem) {
         mem->size = 0;
         if (do_hvf_set_memory(mem, 0)) {
             error_report("Failed to reset overlapping slot");
             abort();
         }
     }

     if (!add) {
         return;
     }

     if (area->readonly ||
         (!memory_region_is_ram(area) && memory_region_is_romd(area))) {
         flags = HV_MEMORY_READ | HV_MEMORY_EXEC;
     } else {
         flags = HV_MEMORY_READ | HV_MEMORY_WRITE | HV_MEMORY_EXEC;
     }

     /* Now make a new slot. */
     int x;

     for (x = 0; x < hvf_state->num_slots; ++x) {
         mem = &hvf_state->slots[x];
         if (!mem->size) {
             break;
         }
     }

     if (x == hvf_state->num_slots) {
         error_report("No free slots");
         abort();
     }

     mem->size = int128_get64(section->size);
     mem->mem = memory_region_get_ram_ptr(area) + section->offset_within_region;
     mem->start = section->offset_within_address_space;
     mem->region = area;

     if (do_hvf_set_memory(mem, flags)) {
         error_report("Error registering new memory slot");
         abort();
     }
 }

 static void do_hvf_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
 {
     if (!cpu->accel->dirty) {
         hvf_get_registers(cpu);
         cpu->accel->dirty = true;
     }
 }

 static void hvf_cpu_synchronize_state(CPUState *cpu)
 {
     if (!cpu->accel->dirty) {
         run_on_cpu(cpu, do_hvf_cpu_synchronize_state, RUN_ON_CPU_NULL);
     }
 }

 static void do_hvf_cpu_synchronize_set_dirty(CPUState *cpu,
                                              run_on_cpu_data arg)
 {
     /* QEMU state is the reference, push it to HVF now and on next entry */
     cpu->accel->dirty = true;
 }

 static void hvf_cpu_synchronize_post_reset(CPUState *cpu)
 {
     run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
 }

 static void hvf_cpu_synchronize_post_init(CPUState *cpu)
 {
     run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
 }

 static void hvf_cpu_synchronize_pre_loadvm(CPUState *cpu)
 {
     run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
 }

 static void hvf_set_dirty_tracking(MemoryRegionSection *section, bool on)
 {
     hvf_slot *slot;

     slot = hvf_find_overlap_slot(
             section->offset_within_address_space,
             int128_get64(section->size));

     /* protect region against writes; begin tracking it */
     if (on) {
         slot->flags |= HVF_SLOT_LOG;
         hv_vm_protect((uintptr_t)slot->start, (size_t)slot->size,
                       HV_MEMORY_READ | HV_MEMORY_EXEC);
     /* stop tracking region*/
     } else {
         slot->flags &= ~HVF_SLOT_LOG;
         hv_vm_protect((uintptr_t)slot->start, (size_t)slot->size,
                       HV_MEMORY_READ | HV_MEMORY_WRITE | HV_MEMORY_EXEC);
     }
 }

 static void hvf_log_start(MemoryListener *listener,
                           MemoryRegionSection *section, int old, int new)
 {
     if (old != 0) {
         return;
     }

     hvf_set_dirty_tracking(section, 1);
 }

 static void hvf_log_stop(MemoryListener *listener,
                          MemoryRegionSection *section, int old, int new)
 {
     if (new != 0) {
         return;
     }

     hvf_set_dirty_tracking(section, 0);
 }

 static void hvf_log_sync(MemoryListener *listener,
                          MemoryRegionSection *section)
 {
     /*
      * sync of dirty pages is handled elsewhere; just make sure we keep
      * tracking the region.
      */
     hvf_set_dirty_tracking(section, 1);
 }

 static void hvf_region_add(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
     hvf_set_phys_mem(section, true);
 }

 static void hvf_region_del(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
     hvf_set_phys_mem(section, false);
 }

 static MemoryListener hvf_memory_listener = {
     .name = "hvf",
     .priority = MEMORY_LISTENER_PRIORITY_ACCEL,
     .region_add = hvf_region_add,
     .region_del = hvf_region_del,
     .log_start = hvf_log_start,
     .log_stop = hvf_log_stop,
     .log_sync = hvf_log_sync,
 };

 static void dummy_signal(int sig)
 {
 }

 bool hvf_allowed;

 static int hvf_accel_init(MachineState *ms)
 {
     int x;
     hv_return_t ret;
     HVFState *s;

     ret = hv_vm_create(HV_VM_DEFAULT);
     assert_hvf_ok(ret);

     s = g_new0(HVFState, 1);

     s->num_slots = ARRAY_SIZE(s->slots);
     for (x = 0; x < s->num_slots; ++x) {
         s->slots[x].size = 0;
         s->slots[x].slot_id = x;
     }

     QTAILQ_INIT(&s->hvf_sw_breakpoints);

     hvf_state = s;
     memory_listener_register(&hvf_memory_listener, &address_space_memory);

     return hvf_arch_init();
 }

 static inline int hvf_gdbstub_sstep_flags(void)
 {
     return SSTEP_ENABLE | SSTEP_NOIRQ;
 }

 static void hvf_accel_class_init(ObjectClass *oc, void *data)
 {
     AccelClass *ac = ACCEL_CLASS(oc);
     ac->name = "HVF";
     ac->init_machine = hvf_accel_init;
     ac->allowed = &hvf_allowed;
     ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags;
 }

 static const TypeInfo hvf_accel_type = {
     .name = TYPE_HVF_ACCEL,
     .parent = TYPE_ACCEL,
     .class_init = hvf_accel_class_init,
 };

 static void hvf_type_init(void)
 {
     type_register_static(&hvf_accel_type);
 }

 type_init(hvf_type_init);

 static void hvf_vcpu_destroy(CPUState *cpu)
 {
     hv_return_t ret = hv_vcpu_destroy(cpu->accel->fd);
     assert_hvf_ok(ret);

     hvf_arch_vcpu_destroy(cpu);
     g_free(cpu->accel);
     cpu->accel = NULL;
 }

 static int hvf_init_vcpu(CPUState *cpu)
 {
     int r;

     cpu->accel = g_new0(AccelCPUState, 1);

     /* init cpu signals */
     struct sigaction sigact;

     memset(&sigact, 0, sizeof(sigact));
     sigact.sa_handler = dummy_signal;
     sigaction(SIG_IPI, &sigact, NULL);

     pthread_sigmask(SIG_BLOCK, NULL, &cpu->accel->unblock_ipi_mask);
     sigdelset(&cpu->accel->unblock_ipi_mask, SIG_IPI);

 #ifdef __aarch64__
     r = hv_vcpu_create(&cpu->accel->fd,
                        (hv_vcpu_exit_t **)&cpu->accel->exit, NULL);
 #else
     r = hv_vcpu_create(&cpu->accel->fd, HV_VCPU_DEFAULT);
 #endif
     cpu->accel->dirty = true;
     assert_hvf_ok(r);

     cpu->accel->guest_debug_enabled = false;

     return hvf_arch_init_vcpu(cpu);
 }

 /*
  * The HVF-specific vCPU thread function. This one should only run when the host
  * CPU supports the VMX "unrestricted guest" feature.
  */
 static void *hvf_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;

     int r;

     assert(hvf_enabled());

     rcu_register_thread();

     bql_lock();
     qemu_thread_get_self(cpu->thread);

     cpu->thread_id = qemu_get_thread_id();
     current_cpu = cpu;

     hvf_init_vcpu(cpu);

     /* signal CPU creation */
     cpu_thread_signal_created(cpu);
     qemu_guest_random_seed_thread_part2(cpu->random_seed);

     do {
         if (cpu_can_run(cpu)) {
             r = hvf_vcpu_exec(cpu);
             if (r == EXCP_DEBUG) {
                 cpu_handle_guest_debug(cpu);
             }
         }
         qemu_wait_io_event(cpu);
     } while (!cpu->unplug || cpu_can_run(cpu));

     hvf_vcpu_destroy(cpu);
     cpu_thread_signal_destroyed(cpu);
     bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }

 static void hvf_start_vcpu_thread(CPUState *cpu)
 {
     char thread_name[VCPU_THREAD_NAME_SIZE];

     /*
      * HVF currently does not support TCG, and only runs in
      * unrestricted-guest mode.
      */
     assert(hvf_enabled());

     snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/HVF",
              cpu->cpu_index);
     qemu_thread_create(cpu->thread, thread_name, hvf_cpu_thread_fn,
                        cpu, QEMU_THREAD_JOINABLE);
 }

 static int hvf_insert_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
 {
     struct hvf_sw_breakpoint *bp;
     int err;

     if (type == GDB_BREAKPOINT_SW) {
         bp = hvf_find_sw_breakpoint(cpu, addr);
         if (bp) {
             bp->use_count++;
             return 0;
         }

         bp = g_new(struct hvf_sw_breakpoint, 1);
         bp->pc = addr;
         bp->use_count = 1;
         err = hvf_arch_insert_sw_breakpoint(cpu, bp);
         if (err) {
             g_free(bp);
             return err;
         }

         QTAILQ_INSERT_HEAD(&hvf_state->hvf_sw_breakpoints, bp, entry);
     } else {
         err = hvf_arch_insert_hw_breakpoint(addr, len, type);
         if (err) {
             return err;
         }
     }

     CPU_FOREACH(cpu) {
         err = hvf_update_guest_debug(cpu);
         if (err) {
             return err;
         }
     }
     return 0;
 }

 static int hvf_remove_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
 {
     struct hvf_sw_breakpoint *bp;
     int err;

     if (type == GDB_BREAKPOINT_SW) {
         bp = hvf_find_sw_breakpoint(cpu, addr);
         if (!bp) {
             return -ENOENT;
         }

         if (bp->use_count > 1) {
             bp->use_count--;
             return 0;
         }

         err = hvf_arch_remove_sw_breakpoint(cpu, bp);
         if (err) {
             return err;
         }

         QTAILQ_REMOVE(&hvf_state->hvf_sw_breakpoints, bp, entry);
         g_free(bp);
     } else {
         err = hvf_arch_remove_hw_breakpoint(addr, len, type);
         if (err) {
             return err;
         }
     }

     CPU_FOREACH(cpu) {
         err = hvf_update_guest_debug(cpu);
         if (err) {
             return err;
         }
     }
     return 0;
 }

 static void hvf_remove_all_breakpoints(CPUState *cpu)
 {
     struct hvf_sw_breakpoint *bp, *next;
     CPUState *tmpcpu;

     QTAILQ_FOREACH_SAFE(bp, &hvf_state->hvf_sw_breakpoints, entry, next) {
         if (hvf_arch_remove_sw_breakpoint(cpu, bp) != 0) {
             /* Try harder to find a CPU that currently sees the breakpoint. */
             CPU_FOREACH(tmpcpu)
             {
                 if (hvf_arch_remove_sw_breakpoint(tmpcpu, bp) == 0) {
                     break;
                 }
             }
         }
         QTAILQ_REMOVE(&hvf_state->hvf_sw_breakpoints, bp, entry);
         g_free(bp);
     }
     hvf_arch_remove_all_hw_breakpoints();

     CPU_FOREACH(cpu) {
         hvf_update_guest_debug(cpu);
     }
 }

 static void hvf_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);

     ops->create_vcpu_thread = hvf_start_vcpu_thread;
     ops->kick_vcpu_thread = hvf_kick_vcpu_thread;

     ops->synchronize_post_reset = hvf_cpu_synchronize_post_reset;
     ops->synchronize_post_init = hvf_cpu_synchronize_post_init;
     ops->synchronize_state = hvf_cpu_synchronize_state;
     ops->synchronize_pre_loadvm = hvf_cpu_synchronize_pre_loadvm;

     ops->insert_breakpoint = hvf_insert_breakpoint;
     ops->remove_breakpoint = hvf_remove_breakpoint;
     ops->remove_all_breakpoints = hvf_remove_all_breakpoints;
     ops->update_guest_debug = hvf_update_guest_debug;
     ops->supports_guest_debug = hvf_arch_supports_guest_debug;
 };
 static const TypeInfo hvf_accel_ops_type = {
     .name = ACCEL_OPS_NAME("hvf"),

     .parent = TYPE_ACCEL_OPS,
     .class_init = hvf_accel_ops_class_init,
     .abstract = true,
 };
 static void hvf_accel_ops_register_types(void)
 {
     type_register_static(&hvf_accel_ops_type);
 }
 type_init(hvf_accel_ops_register_types);
	/*
	* Copyright 2008 IBM Corporation
	* 2008 Red Hat, Inc.
	* Copyright 2011 Intel Corporation
	* Copyright 2016 Veertu, Inc.
	* Copyright 2017 The Android Open Source Project
	*
	* QEMU Hypervisor.framework support
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of version 2 of the GNU General Public
	* License as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*
	* This file contain code under public domain from the hvdos project:
	* https://github.com/mist64/hvdos
	*
	* Parts Copyright (c) 2011 NetApp, Inc.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	#include "qemu/osdep.h"
	#include "qemu/error-report.h"
	#include "qemu/main-loop.h"
	#include "exec/address-spaces.h"
	#include "exec/exec-all.h"
	#include "exec/gdbstub.h"
	#include "sysemu/cpus.h"
	#include "sysemu/hvf.h"
	#include "sysemu/hvf_int.h"
	#include "sysemu/runstate.h"
	#include "qemu/guest-random.h"

	HVFState *hvf_state;

	#ifdef __aarch64__
	#define HV_VM_DEFAULT NULL
	#endif

	/* Memory slots */

	hvf_slot *hvf_find_overlap_slot(uint64_t start, uint64_t size)
	{
	hvf_slot *slot;
	int x;
	for (x = 0; x < hvf_state->num_slots; ++x) {
	slot = &hvf_state->slots[x];
	if (slot->size && start < (slot->start + slot->size) &&
	(start + size) > slot->start) {
	return slot;
	}
	}
	return NULL;
	}

	struct mac_slot {
	int present;
	uint64_t size;
	uint64_t gpa_start;
	uint64_t gva;
	};

	struct mac_slot mac_slots[32];

	static int do_hvf_set_memory(hvf_slot *slot, hv_memory_flags_t flags)
	{
	struct mac_slot *macslot;
	hv_return_t ret;

	macslot = &mac_slots[slot->slot_id];

	if (macslot->present) {
	if (macslot->size != slot->size) {
	macslot->present = 0;
	ret = hv_vm_unmap(macslot->gpa_start, macslot->size);
	assert_hvf_ok(ret);
	}
	}

	if (!slot->size) {
	return 0;
	}

	macslot->present = 1;
	macslot->gpa_start = slot->start;
	macslot->size = slot->size;
	ret = hv_vm_map(slot->mem, slot->start, slot->size, flags);
	assert_hvf_ok(ret);
	return 0;
	}

	static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
	{
	hvf_slot *mem;
	MemoryRegion *area = section->mr;
	bool writable = !area->readonly && !area->rom_device;
	hv_memory_flags_t flags;
	uint64_t page_size = qemu_real_host_page_size();

	if (!memory_region_is_ram(area)) {
	if (writable) {
	return;
	} else if (!memory_region_is_romd(area)) {
	/*
	* If the memory device is not in romd_mode, then we actually want
	* to remove the hvf memory slot so all accesses will trap.
	*/
	add = false;
	}
	}

	if (!QEMU_IS_ALIGNED(int128_get64(section->size), page_size) \|\|
	!QEMU_IS_ALIGNED(section->offset_within_address_space, page_size)) {
	/* Not page aligned, so we can not map as RAM */
	add = false;
	}

	mem = hvf_find_overlap_slot(
	section->offset_within_address_space,
	int128_get64(section->size));

	if (mem && add) {
	if (mem->size == int128_get64(section->size) &&
	mem->start == section->offset_within_address_space &&
	mem->mem == (memory_region_get_ram_ptr(area) +
	section->offset_within_region)) {
	return; /* Same region was attempted to register, go away. */
	}
	}

	/* Region needs to be reset. set the size to 0 and remap it. */
	if (mem) {
	mem->size = 0;
	if (do_hvf_set_memory(mem, 0)) {
	error_report("Failed to reset overlapping slot");
	abort();
	}
	}

	if (!add) {
	return;
	}

	if (area->readonly \|\|
	(!memory_region_is_ram(area) && memory_region_is_romd(area))) {
	flags = HV_MEMORY_READ \| HV_MEMORY_EXEC;
	} else {
	flags = HV_MEMORY_READ \| HV_MEMORY_WRITE \| HV_MEMORY_EXEC;
	}

	/* Now make a new slot. */
	int x;

	for (x = 0; x < hvf_state->num_slots; ++x) {
	mem = &hvf_state->slots[x];
	if (!mem->size) {
	break;
	}
	}

	if (x == hvf_state->num_slots) {
	error_report("No free slots");
	abort();
	}

	mem->size = int128_get64(section->size);
	mem->mem = memory_region_get_ram_ptr(area) + section->offset_within_region;
	mem->start = section->offset_within_address_space;
	mem->region = area;

	if (do_hvf_set_memory(mem, flags)) {
	error_report("Error registering new memory slot");
	abort();
	}
	}

	static void do_hvf_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
	{
	if (!cpu->accel->dirty) {
	hvf_get_registers(cpu);
	cpu->accel->dirty = true;
	}
	}

	static void hvf_cpu_synchronize_state(CPUState *cpu)
	{
	if (!cpu->accel->dirty) {
	run_on_cpu(cpu, do_hvf_cpu_synchronize_state, RUN_ON_CPU_NULL);
	}
	}

	static void do_hvf_cpu_synchronize_set_dirty(CPUState *cpu,
	run_on_cpu_data arg)
	{
	/* QEMU state is the reference, push it to HVF now and on next entry */
	cpu->accel->dirty = true;
	}

	static void hvf_cpu_synchronize_post_reset(CPUState *cpu)
	{
	run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
	}

	static void hvf_cpu_synchronize_post_init(CPUState *cpu)
	{
	run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
	}

	static void hvf_cpu_synchronize_pre_loadvm(CPUState *cpu)
	{
	run_on_cpu(cpu, do_hvf_cpu_synchronize_set_dirty, RUN_ON_CPU_NULL);
	}

	static void hvf_set_dirty_tracking(MemoryRegionSection *section, bool on)
	{
	hvf_slot *slot;

	slot = hvf_find_overlap_slot(
	section->offset_within_address_space,
	int128_get64(section->size));

	/* protect region against writes; begin tracking it */
	if (on) {
	slot->flags \|= HVF_SLOT_LOG;
	hv_vm_protect((uintptr_t)slot->start, (size_t)slot->size,
	HV_MEMORY_READ \| HV_MEMORY_EXEC);
	/* stop tracking region*/
	} else {
	slot->flags &= ~HVF_SLOT_LOG;
	hv_vm_protect((uintptr_t)slot->start, (size_t)slot->size,
	HV_MEMORY_READ \| HV_MEMORY_WRITE \| HV_MEMORY_EXEC);
	}
	}

	static void hvf_log_start(MemoryListener *listener,
	MemoryRegionSection *section, int old, int new)
	{
	if (old != 0) {
	return;
	}

	hvf_set_dirty_tracking(section, 1);
	}

	static void hvf_log_stop(MemoryListener *listener,
	MemoryRegionSection *section, int old, int new)
	{
	if (new != 0) {
	return;
	}

	hvf_set_dirty_tracking(section, 0);
	}

	static void hvf_log_sync(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	/*
	* sync of dirty pages is handled elsewhere; just make sure we keep
	* tracking the region.
	*/
	hvf_set_dirty_tracking(section, 1);
	}

	static void hvf_region_add(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	hvf_set_phys_mem(section, true);
	}

	static void hvf_region_del(MemoryListener *listener,
	MemoryRegionSection *section)
	{
	hvf_set_phys_mem(section, false);
	}

	static MemoryListener hvf_memory_listener = {
	.name = "hvf",
	.priority = MEMORY_LISTENER_PRIORITY_ACCEL,
	.region_add = hvf_region_add,
	.region_del = hvf_region_del,
	.log_start = hvf_log_start,
	.log_stop = hvf_log_stop,
	.log_sync = hvf_log_sync,
	};

	static void dummy_signal(int sig)
	{
	}

	bool hvf_allowed;

	static int hvf_accel_init(MachineState *ms)
	{
	int x;
	hv_return_t ret;
	HVFState *s;

	ret = hv_vm_create(HV_VM_DEFAULT);
	assert_hvf_ok(ret);

	s = g_new0(HVFState, 1);

	s->num_slots = ARRAY_SIZE(s->slots);
	for (x = 0; x < s->num_slots; ++x) {
	s->slots[x].size = 0;
	s->slots[x].slot_id = x;
	}

	QTAILQ_INIT(&s->hvf_sw_breakpoints);

	hvf_state = s;
	memory_listener_register(&hvf_memory_listener, &address_space_memory);

	return hvf_arch_init();
	}

	static inline int hvf_gdbstub_sstep_flags(void)
	{
	return SSTEP_ENABLE \| SSTEP_NOIRQ;
	}

	static void hvf_accel_class_init(ObjectClass oc, void data)
	{
	AccelClass *ac = ACCEL_CLASS(oc);
	ac->name = "HVF";
	ac->init_machine = hvf_accel_init;
	ac->allowed = &hvf_allowed;
	ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags;
	}

	static const TypeInfo hvf_accel_type = {
	.name = TYPE_HVF_ACCEL,
	.parent = TYPE_ACCEL,
	.class_init = hvf_accel_class_init,
	};

	static void hvf_type_init(void)
	{
	type_register_static(&hvf_accel_type);
	}

	type_init(hvf_type_init);

	static void hvf_vcpu_destroy(CPUState *cpu)
	{
	hv_return_t ret = hv_vcpu_destroy(cpu->accel->fd);
	assert_hvf_ok(ret);

	hvf_arch_vcpu_destroy(cpu);
	g_free(cpu->accel);
	cpu->accel = NULL;
	}

	static int hvf_init_vcpu(CPUState *cpu)
	{
	int r;

	cpu->accel = g_new0(AccelCPUState, 1);

	/* init cpu signals */
	struct sigaction sigact;

	memset(&sigact, 0, sizeof(sigact));
	sigact.sa_handler = dummy_signal;
	sigaction(SIG_IPI, &sigact, NULL);

	pthread_sigmask(SIG_BLOCK, NULL, &cpu->accel->unblock_ipi_mask);
	sigdelset(&cpu->accel->unblock_ipi_mask, SIG_IPI);

	#ifdef __aarch64__
	r = hv_vcpu_create(&cpu->accel->fd,
	(hv_vcpu_exit_t **)&cpu->accel->exit, NULL);
	#else
	r = hv_vcpu_create(&cpu->accel->fd, HV_VCPU_DEFAULT);
	#endif
	cpu->accel->dirty = true;
	assert_hvf_ok(r);

	cpu->accel->guest_debug_enabled = false;

	return hvf_arch_init_vcpu(cpu);
	}

	/*
	* The HVF-specific vCPU thread function. This one should only run when the host
	* CPU supports the VMX "unrestricted guest" feature.
	*/
	static void hvf_cpu_thread_fn(void arg)
	{
	CPUState *cpu = arg;

	int r;

	assert(hvf_enabled());

	rcu_register_thread();

	bql_lock();
	qemu_thread_get_self(cpu->thread);

	cpu->thread_id = qemu_get_thread_id();
	current_cpu = cpu;

	hvf_init_vcpu(cpu);

	/* signal CPU creation */
	cpu_thread_signal_created(cpu);
	qemu_guest_random_seed_thread_part2(cpu->random_seed);

	do {
	if (cpu_can_run(cpu)) {
	r = hvf_vcpu_exec(cpu);
	if (r == EXCP_DEBUG) {
	cpu_handle_guest_debug(cpu);
	}
	}
	qemu_wait_io_event(cpu);
	} while (!cpu->unplug \|\| cpu_can_run(cpu));

	hvf_vcpu_destroy(cpu);
	cpu_thread_signal_destroyed(cpu);
	bql_unlock();
	rcu_unregister_thread();
	return NULL;
	}

	static void hvf_start_vcpu_thread(CPUState *cpu)
	{
	char thread_name[VCPU_THREAD_NAME_SIZE];

	/*
	* HVF currently does not support TCG, and only runs in
	* unrestricted-guest mode.
	*/
	assert(hvf_enabled());

	snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/HVF",
	cpu->cpu_index);
	qemu_thread_create(cpu->thread, thread_name, hvf_cpu_thread_fn,
	cpu, QEMU_THREAD_JOINABLE);
	}

	static int hvf_insert_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
	{
	struct hvf_sw_breakpoint *bp;
	int err;

	if (type == GDB_BREAKPOINT_SW) {
	bp = hvf_find_sw_breakpoint(cpu, addr);
	if (bp) {
	bp->use_count++;
	return 0;
	}

	bp = g_new(struct hvf_sw_breakpoint, 1);
	bp->pc = addr;
	bp->use_count = 1;
	err = hvf_arch_insert_sw_breakpoint(cpu, bp);
	if (err) {
	g_free(bp);
	return err;
	}

	QTAILQ_INSERT_HEAD(&hvf_state->hvf_sw_breakpoints, bp, entry);
	} else {
	err = hvf_arch_insert_hw_breakpoint(addr, len, type);
	if (err) {
	return err;
	}
	}

	CPU_FOREACH(cpu) {
	err = hvf_update_guest_debug(cpu);
	if (err) {
	return err;
	}
	}
	return 0;
	}

	static int hvf_remove_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
	{
	struct hvf_sw_breakpoint *bp;
	int err;

	if (type == GDB_BREAKPOINT_SW) {
	bp = hvf_find_sw_breakpoint(cpu, addr);
	if (!bp) {
	return -ENOENT;
	}

	if (bp->use_count > 1) {
	bp->use_count--;
	return 0;
	}

	err = hvf_arch_remove_sw_breakpoint(cpu, bp);
	if (err) {
	return err;
	}

	QTAILQ_REMOVE(&hvf_state->hvf_sw_breakpoints, bp, entry);
	g_free(bp);
	} else {
	err = hvf_arch_remove_hw_breakpoint(addr, len, type);
	if (err) {
	return err;
	}
	}

	CPU_FOREACH(cpu) {
	err = hvf_update_guest_debug(cpu);
	if (err) {
	return err;
	}
	}
	return 0;
	}

	static void hvf_remove_all_breakpoints(CPUState *cpu)
	{
	struct hvf_sw_breakpoint bp, next;
	CPUState *tmpcpu;

	QTAILQ_FOREACH_SAFE(bp, &hvf_state->hvf_sw_breakpoints, entry, next) {
	if (hvf_arch_remove_sw_breakpoint(cpu, bp) != 0) {
	/* Try harder to find a CPU that currently sees the breakpoint. */
	CPU_FOREACH(tmpcpu)
	{
	if (hvf_arch_remove_sw_breakpoint(tmpcpu, bp) == 0) {
	break;
	}
	}
	}
	QTAILQ_REMOVE(&hvf_state->hvf_sw_breakpoints, bp, entry);
	g_free(bp);
	}
	hvf_arch_remove_all_hw_breakpoints();

	CPU_FOREACH(cpu) {
	hvf_update_guest_debug(cpu);
	}
	}

	static void hvf_accel_ops_class_init(ObjectClass oc, void data)
	{
	AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);

	ops->create_vcpu_thread = hvf_start_vcpu_thread;
	ops->kick_vcpu_thread = hvf_kick_vcpu_thread;

	ops->synchronize_post_reset = hvf_cpu_synchronize_post_reset;
	ops->synchronize_post_init = hvf_cpu_synchronize_post_init;
	ops->synchronize_state = hvf_cpu_synchronize_state;
	ops->synchronize_pre_loadvm = hvf_cpu_synchronize_pre_loadvm;

	ops->insert_breakpoint = hvf_insert_breakpoint;
	ops->remove_breakpoint = hvf_remove_breakpoint;
	ops->remove_all_breakpoints = hvf_remove_all_breakpoints;
	ops->update_guest_debug = hvf_update_guest_debug;
	ops->supports_guest_debug = hvf_arch_supports_guest_debug;
	};
	static const TypeInfo hvf_accel_ops_type = {
	.name = ACCEL_OPS_NAME("hvf"),

	.parent = TYPE_ACCEL_OPS,
	.class_init = hvf_accel_ops_class_init,
	.abstract = true,
	};
	static void hvf_accel_ops_register_types(void)
	{
	type_register_static(&hvf_accel_ops_type);
	}
	type_init(hvf_accel_ops_register_types);