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/*

 * QEMU memory mapping

 *

 * Copyright Fujitsu, Corp. 2011, 2012

 *

 * Authors:

 *     Wen Congyang <wency@cn.fujitsu.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 *

 */

#include <glib.h>

#include "cpu.h"

#include "exec/cpu-all.h"

#include "sysemu/memory_mapping.h"

#include "exec/memory.h"

#include "exec/address-spaces.h"

//#define DEBUG_GUEST_PHYS_REGION_ADD

static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,

                                                   MemoryMapping *mapping)

{

    MemoryMapping *p;

    QTAILQ_FOREACH(p, &list->head, next) {

        if (p->phys_addr >= mapping->phys_addr) {

            QTAILQ_INSERT_BEFORE(p, mapping, next);

            return;

        }

    }

    QTAILQ_INSERT_TAIL(&list->head, mapping, next);

}

static void create_new_memory_mapping(MemoryMappingList *list,

                                      hwaddr phys_addr,

                                      hwaddr virt_addr,

                                      ram_addr_t length)

{

    MemoryMapping *memory_mapping;

    memory_mapping = g_malloc(sizeof(MemoryMapping));

    memory_mapping->phys_addr = phys_addr;

    memory_mapping->virt_addr = virt_addr;

    memory_mapping->length = length;

    list->last_mapping = memory_mapping;

    list->num++;

    memory_mapping_list_add_mapping_sorted(list, memory_mapping);

}

static inline bool mapping_contiguous(MemoryMapping *map,

                                      hwaddr phys_addr,

                                      hwaddr virt_addr)

{

    return phys_addr == map->phys_addr + map->length &&

           virt_addr == map->virt_addr + map->length;

}

/*

 * [map->phys_addr, map->phys_addr + map->length) and

 * [phys_addr, phys_addr + length) have intersection?

 */

static inline bool mapping_have_same_region(MemoryMapping *map,

                                            hwaddr phys_addr,

                                            ram_addr_t length)

{

    return !(phys_addr + length < map->phys_addr ||

             phys_addr >= map->phys_addr + map->length);

}

/*

 * [map->phys_addr, map->phys_addr + map->length) and

 * [phys_addr, phys_addr + length) have intersection. The virtual address in the

 * intersection are the same?

 */

static inline bool mapping_conflict(MemoryMapping *map,

                                    hwaddr phys_addr,

                                    hwaddr virt_addr)

{

    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;

}

/*

 * [map->virt_addr, map->virt_addr + map->length) and

 * [virt_addr, virt_addr + length) have intersection. And the physical address

 * in the intersection are the same.

 */

static inline void mapping_merge(MemoryMapping *map,

                                 hwaddr virt_addr,

                                 ram_addr_t length)

{

    if (virt_addr < map->virt_addr) {

        map->length += map->virt_addr - virt_addr;

        map->virt_addr = virt_addr;

    }

    if ((virt_addr + length) >

        (map->virt_addr + map->length)) {

        map->length = virt_addr + length - map->virt_addr;

    }

}

void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,

                                          hwaddr phys_addr,

                                          hwaddr virt_addr,

                                          ram_addr_t length)

{

    MemoryMapping *memory_mapping, *last_mapping;

    if (QTAILQ_EMPTY(&list->head)) {

        create_new_memory_mapping(list, phys_addr, virt_addr, length);

        return;

    }

    last_mapping = list->last_mapping;

    if (last_mapping) {

        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {

            last_mapping->length += length;

            return;

        }

    }

    QTAILQ_FOREACH(memory_mapping, &list->head, next) {

        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {

            memory_mapping->length += length;

            list->last_mapping = memory_mapping;

            return;

        }

        if (phys_addr + length < memory_mapping->phys_addr) {

            /* create a new region before memory_mapping */

            break;

        }

        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {

            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {

                continue;

            }

            /* merge this region into memory_mapping */

            mapping_merge(memory_mapping, virt_addr, length);

            list->last_mapping = memory_mapping;

            return;

        }

    }

    /* this region can not be merged into any existed memory mapping. */

    create_new_memory_mapping(list, phys_addr, virt_addr, length);

}

void memory_mapping_list_free(MemoryMappingList *list)

{

    MemoryMapping *p, *q;

    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {

        QTAILQ_REMOVE(&list->head, p, next);

        g_free(p);

    }

    list->num = 0;

    list->last_mapping = NULL;

}

void memory_mapping_list_init(MemoryMappingList *list)

{

    list->num = 0;

    list->last_mapping = NULL;

    QTAILQ_INIT(&list->head);

}

void guest_phys_blocks_free(GuestPhysBlockList *list)

{

    GuestPhysBlock *p, *q;

    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {

        QTAILQ_REMOVE(&list->head, p, next);

        g_free(p);

    }

    list->num = 0;

}

void guest_phys_blocks_init(GuestPhysBlockList *list)

{

    list->num = 0;

    QTAILQ_INIT(&list->head);

}

typedef struct GuestPhysListener {

    GuestPhysBlockList *list;

    MemoryListener listener;

} GuestPhysListener;

static void guest_phys_blocks_region_add(MemoryListener *listener,

                                         MemoryRegionSection *section)

{

    GuestPhysListener *g;

    uint64_t section_size;

    hwaddr target_start, target_end;

    uint8_t *host_addr;

    GuestPhysBlock *predecessor;

    /* we only care about RAM */

    if (!memory_region_is_ram(section->mr)) {

        return;

    }

    g            = container_of(listener, GuestPhysListener, listener);

    section_size = int128_get64(section->size);

    target_start = section->offset_within_address_space;

    target_end   = target_start + section_size;

    host_addr    = memory_region_get_ram_ptr(section->mr) +

                   section->offset_within_region;

    predecessor  = NULL;

    /* find continuity in guest physical address space */

    if (!QTAILQ_EMPTY(&g->list->head)) {

        hwaddr predecessor_size;

        predecessor = QTAILQ_LAST(&g->list->head, GuestPhysBlockHead);

        predecessor_size = predecessor->target_end - predecessor->target_start;

        /* the memory API guarantees monotonically increasing traversal */

        g_assert(predecessor->target_end <= target_start);

        /* we want continuity in both guest-physical and host-virtual memory */

        if (predecessor->target_end < target_start ||

            predecessor->host_addr + predecessor_size != host_addr) {

            predecessor = NULL;

        }

    }

    if (predecessor == NULL) {

        /* isolated mapping, allocate it and add it to the list */

        GuestPhysBlock *block = g_malloc0(sizeof *block);

        block->target_start = target_start;

        block->target_end   = target_end;

        block->host_addr    = host_addr;

        QTAILQ_INSERT_TAIL(&g->list->head, block, next);

        ++g->list->num;

    } else {

        /* expand predecessor until @target_end; predecessor's start doesn't

         * change

         */

        predecessor->target_end = target_end;

    }

#ifdef DEBUG_GUEST_PHYS_REGION_ADD

    fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="

            TARGET_FMT_plx ": %s (count: %u)\n", __FUNCTION__, target_start,

            target_end, predecessor ? "joined" : "added", g->list->num);

#endif

}

void guest_phys_blocks_append(GuestPhysBlockList *list)

{

    GuestPhysListener g = { 0 };

    g.list = list;

    g.listener.region_add = &guest_phys_blocks_region_add;

    memory_listener_register(&g.listener, &address_space_memory);

    memory_listener_unregister(&g.listener);

}

static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)

{

    CPUState *cpu;

    CPU_FOREACH(cpu) {

        if (cpu_paging_enabled(cpu)) {

            return cpu;

        }

    }

    return NULL;

}

void qemu_get_guest_memory_mapping(MemoryMappingList *list,

                                   const GuestPhysBlockList *guest_phys_blocks,

                                   Error **errp)

{

    CPUState *cpu, *first_paging_enabled_cpu;

    GuestPhysBlock *block;

    ram_addr_t offset, length;

    first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);

    if (first_paging_enabled_cpu) {

        for (cpu = first_paging_enabled_cpu; cpu != NULL;

             cpu = CPU_NEXT(cpu)) {

            Error *err = NULL;

            cpu_get_memory_mapping(cpu, list, &err);

            if (err) {

                error_propagate(errp, err);

                return;

            }

        }

        return;

    }

    /*

     * If the guest doesn't use paging, the virtual address is equal to physical

     * address.

     */

    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {

        offset = block->target_start;

        length = block->target_end - block->target_start;

        create_new_memory_mapping(list, offset, offset, length);

    }

}

void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,

                                   const GuestPhysBlockList *guest_phys_blocks)

{

    GuestPhysBlock *block;

    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {

        create_new_memory_mapping(list, block->target_start, 0,

                                  block->target_end - block->target_start);

    }

}

void memory_mapping_filter(MemoryMappingList *list, int64_t begin,

                           int64_t length)

{

    MemoryMapping *cur, *next;

    QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {

        if (cur->phys_addr >= begin + length ||

            cur->phys_addr + cur->length <= begin) {

            QTAILQ_REMOVE(&list->head, cur, next);

            list->num--;

            continue;

        }

        if (cur->phys_addr < begin) {

            cur->length -= begin - cur->phys_addr;

            if (cur->virt_addr) {

                cur->virt_addr += begin - cur->phys_addr;

            }

            cur->phys_addr = begin;

        }

        if (cur->phys_addr + cur->length > begin + length) {

            cur->length -= cur->phys_addr + cur->length - begin - length;

        }

    }

}