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vfio: Generalize region support

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Both platform and PCI vfio drivers create a "slow", I/O memory region
with one or more mmap memory regions overlayed when supported by the
device. Generalize this to a set of common helpers in the core that
pulls the region info from vfio, fills the region data, configures
slow mapping, and adds helpers for comleting the mmap, enable/disable,
and teardown.  This can be immediately used by the PCI MSI-X code,
which needs to mmap around the MSI-X vector table.

This also changes VFIORegion.mem to be dynamically allocated because
otherwise we don't know how the caller has allocated VFIORegion and
therefore don't know whether to unreference it to destroy the
MemoryRegion or not.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alex Williamson 2016-03-10 09:39:07 -07:00
parent 469002263a
commit db0da029a1
7 changed files with 290 additions and 197 deletions
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186
hw/vfio/common.c
View file

@ -493,46 +493,162 @@ static void vfio_listener_release(VFIOContainer *container)
memory_listener_unregister(&container->listener);
}
int vfio_mmap_region(Object *obj, VFIORegion *region,
MemoryRegion *mem, MemoryRegion *submem,
void **map, size_t size, off_t offset,
const char *name)
int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
int index, const char *name)
{
int ret = 0;
VFIODevice *vbasedev = region->vbasedev;
struct vfio_region_info *info;
int ret;
if (!vbasedev->no_mmap && size && region->flags &
VFIO_REGION_INFO_FLAG_MMAP) {
int prot = 0;
if (region->flags & VFIO_REGION_INFO_FLAG_READ) {
prot |= PROT_READ;
}
if (region->flags & VFIO_REGION_INFO_FLAG_WRITE) {
prot |= PROT_WRITE;
}
*map = mmap(NULL, size, prot, MAP_SHARED,
vbasedev->fd,
region->fd_offset + offset);
if (*map == MAP_FAILED) {
*map = NULL;
ret = -errno;
goto empty_region;
}
memory_region_init_ram_ptr(submem, obj, name, size, *map);
memory_region_set_skip_dump(submem);
} else {
empty_region:
/* Create a zero sized sub-region to make cleanup easy. */
memory_region_init(submem, obj, name, 0);
ret = vfio_get_region_info(vbasedev, index, &info);
if (ret) {
return ret;
}
memory_region_add_subregion(mem, offset, submem);
region->vbasedev = vbasedev;
region->flags = info->flags;
region->size = info->size;
region->fd_offset = info->offset;
region->nr = index;
return ret;
if (region->size) {
region->mem = g_new0(MemoryRegion, 1);
memory_region_init_io(region->mem, obj, &vfio_region_ops,
region, name, region->size);
if (!vbasedev->no_mmap &&
region->flags & VFIO_REGION_INFO_FLAG_MMAP &&
!(region->size & ~qemu_real_host_page_mask)) {
region->nr_mmaps = 1;
region->mmaps = g_new0(VFIOMmap, region->nr_mmaps);
region->mmaps[0].offset = 0;
region->mmaps[0].size = region->size;
}
}
g_free(info);
trace_vfio_region_setup(vbasedev->name, index, name,
region->flags, region->fd_offset, region->size);
return 0;
}
int vfio_region_mmap(VFIORegion *region)
{
int i, prot = 0;
char *name;
if (!region->mem) {
return 0;
}
prot |= region->flags & VFIO_REGION_INFO_FLAG_READ ? PROT_READ : 0;
prot |= region->flags & VFIO_REGION_INFO_FLAG_WRITE ? PROT_WRITE : 0;
for (i = 0; i < region->nr_mmaps; i++) {
region->mmaps[i].mmap = mmap(NULL, region->mmaps[i].size, prot,
MAP_SHARED, region->vbasedev->fd,
region->fd_offset +
region->mmaps[i].offset);
if (region->mmaps[i].mmap == MAP_FAILED) {
int ret = -errno;
trace_vfio_region_mmap_fault(memory_region_name(region->mem), i,
region->fd_offset +
region->mmaps[i].offset,
region->fd_offset +
region->mmaps[i].offset +
region->mmaps[i].size - 1, ret);
region->mmaps[i].mmap = NULL;
for (i--; i >= 0; i--) {
memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
munmap(region->mmaps[i].mmap, region->mmaps[i].size);
object_unparent(OBJECT(&region->mmaps[i].mem));
region->mmaps[i].mmap = NULL;
}
return ret;
}
name = g_strdup_printf("%s mmaps[%d]",
memory_region_name(region->mem), i);
memory_region_init_ram_ptr(&region->mmaps[i].mem,
memory_region_owner(region->mem),
name, region->mmaps[i].size,
region->mmaps[i].mmap);
g_free(name);
memory_region_set_skip_dump(&region->mmaps[i].mem);
memory_region_add_subregion(region->mem, region->mmaps[i].offset,
&region->mmaps[i].mem);
trace_vfio_region_mmap(memory_region_name(&region->mmaps[i].mem),
region->mmaps[i].offset,
region->mmaps[i].offset +
region->mmaps[i].size - 1);
}
return 0;
}
void vfio_region_exit(VFIORegion *region)
{
int i;
if (!region->mem) {
return;
}
for (i = 0; i < region->nr_mmaps; i++) {
if (region->mmaps[i].mmap) {
memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
}
}
trace_vfio_region_exit(region->vbasedev->name, region->nr);
}
void vfio_region_finalize(VFIORegion *region)
{
int i;
if (!region->mem) {
return;
}
for (i = 0; i < region->nr_mmaps; i++) {
if (region->mmaps[i].mmap) {
munmap(region->mmaps[i].mmap, region->mmaps[i].size);
object_unparent(OBJECT(&region->mmaps[i].mem));
}
}
object_unparent(OBJECT(region->mem));
g_free(region->mem);
g_free(region->mmaps);
trace_vfio_region_finalize(region->vbasedev->name, region->nr);
}
void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled)
{
int i;
if (!region->mem) {
return;
}
for (i = 0; i < region->nr_mmaps; i++) {
if (region->mmaps[i].mmap) {
memory_region_set_enabled(&region->mmaps[i].mem, enabled);
}
}
trace_vfio_region_mmaps_set_enabled(memory_region_name(region->mem),
enabled);
}
void vfio_reset_handler(void *opaque)