blob: 380537e06d893e5a9f6f9082fe305a81c1e4cb60 [file] [log] [blame]
/*
* Thread-safe guest to host memory mapping
*
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.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 "exec/address-spaces.h"
#include "hostmem.h"
static int hostmem_lookup_cmp(const void *phys_, const void *region_)
{
hwaddr phys = *(const hwaddr *)phys_;
const HostMemRegion *region = region_;
if (phys < region->guest_addr) {
return -1;
} else if (phys >= region->guest_addr + region->size) {
return 1;
} else {
return 0;
}
}
/**
* Map guest physical address to host pointer
*/
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write)
{
HostMemRegion *region;
void *host_addr = NULL;
hwaddr offset_within_region;
qemu_mutex_lock(&hostmem->current_regions_lock);
region = bsearch(&phys, hostmem->current_regions,
hostmem->num_current_regions,
sizeof(hostmem->current_regions[0]),
hostmem_lookup_cmp);
if (!region) {
goto out;
}
if (is_write && region->readonly) {
goto out;
}
offset_within_region = phys - region->guest_addr;
if (len <= region->size - offset_within_region) {
host_addr = region->host_addr + offset_within_region;
}
out:
qemu_mutex_unlock(&hostmem->current_regions_lock);
return host_addr;
}
/**
* Install new regions list
*/
static void hostmem_listener_commit(MemoryListener *listener)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
qemu_mutex_lock(&hostmem->current_regions_lock);
g_free(hostmem->current_regions);
hostmem->current_regions = hostmem->new_regions;
hostmem->num_current_regions = hostmem->num_new_regions;
qemu_mutex_unlock(&hostmem->current_regions_lock);
/* Reset new regions list */
hostmem->new_regions = NULL;
hostmem->num_new_regions = 0;
}
/**
* Add a MemoryRegionSection to the new regions list
*/
static void hostmem_append_new_region(HostMem *hostmem,
MemoryRegionSection *section)
{
void *ram_ptr = memory_region_get_ram_ptr(section->mr);
size_t num = hostmem->num_new_regions;
size_t new_size = (num + 1) * sizeof(hostmem->new_regions[0]);
hostmem->new_regions = g_realloc(hostmem->new_regions, new_size);
hostmem->new_regions[num] = (HostMemRegion){
.host_addr = ram_ptr + section->offset_within_region,
.guest_addr = section->offset_within_address_space,
.size = section->size,
.readonly = section->readonly,
};
hostmem->num_new_regions++;
}
static void hostmem_listener_append_region(MemoryListener *listener,
MemoryRegionSection *section)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
/* Ignore non-RAM regions, we may not be able to map them */
if (!memory_region_is_ram(section->mr)) {
return;
}
/* Ignore regions with dirty logging, we cannot mark them dirty */
if (memory_region_is_logging(section->mr)) {
return;
}
hostmem_append_new_region(hostmem, section);
}
/* We don't implement most MemoryListener callbacks, use these nop stubs */
static void hostmem_listener_dummy(MemoryListener *listener)
{
}
static void hostmem_listener_section_dummy(MemoryListener *listener,
MemoryRegionSection *section)
{
}
static void hostmem_listener_eventfd_dummy(MemoryListener *listener,
MemoryRegionSection *section,
bool match_data, uint64_t data,
EventNotifier *e)
{
}
static void hostmem_listener_coalesced_mmio_dummy(MemoryListener *listener,
MemoryRegionSection *section,
hwaddr addr, hwaddr len)
{
}
void hostmem_init(HostMem *hostmem)
{
memset(hostmem, 0, sizeof(*hostmem));
qemu_mutex_init(&hostmem->current_regions_lock);
hostmem->listener = (MemoryListener){
.begin = hostmem_listener_dummy,
.commit = hostmem_listener_commit,
.region_add = hostmem_listener_append_region,
.region_del = hostmem_listener_section_dummy,
.region_nop = hostmem_listener_append_region,
.log_start = hostmem_listener_section_dummy,
.log_stop = hostmem_listener_section_dummy,
.log_sync = hostmem_listener_section_dummy,
.log_global_start = hostmem_listener_dummy,
.log_global_stop = hostmem_listener_dummy,
.eventfd_add = hostmem_listener_eventfd_dummy,
.eventfd_del = hostmem_listener_eventfd_dummy,
.coalesced_mmio_add = hostmem_listener_coalesced_mmio_dummy,
.coalesced_mmio_del = hostmem_listener_coalesced_mmio_dummy,
.priority = 10,
};
memory_listener_register(&hostmem->listener, &address_space_memory);
if (hostmem->num_new_regions > 0) {
hostmem_listener_commit(&hostmem->listener);
}
}
void hostmem_finalize(HostMem *hostmem)
{
memory_listener_unregister(&hostmem->listener);
g_free(hostmem->new_regions);
g_free(hostmem->current_regions);
qemu_mutex_destroy(&hostmem->current_regions_lock);
}