vfio: Enable sparse mmap capability

The sparse mmap capability in a vfio region info allows vfio to tell
us which sub-areas of a region may be mmap'd.  Thus rather than
assuming a single mmap covers the entire region and later frobbing it
ourselves for things like the PCI MSI-X vector table, we can read that
directly from vfio.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Alex Williamson 2016-05-26 09:43:20 -06:00
parent 2c56d06baf
commit b53b0f696b
2 changed files with 65 additions and 4 deletions

View File

@ -499,6 +499,54 @@ static void vfio_listener_release(VFIOContainer *container)
memory_listener_unregister(&container->listener);
}
static struct vfio_info_cap_header *
vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id)
{
struct vfio_info_cap_header *hdr;
void *ptr = info;
if (!(info->flags & VFIO_REGION_INFO_FLAG_CAPS)) {
return NULL;
}
for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
if (hdr->id == id) {
return hdr;
}
}
return NULL;
}
static void vfio_setup_region_sparse_mmaps(VFIORegion *region,
struct vfio_region_info *info)
{
struct vfio_info_cap_header *hdr;
struct vfio_region_info_cap_sparse_mmap *sparse;
int i;
hdr = vfio_get_region_info_cap(info, VFIO_REGION_INFO_CAP_SPARSE_MMAP);
if (!hdr) {
return;
}
sparse = container_of(hdr, struct vfio_region_info_cap_sparse_mmap, header);
trace_vfio_region_sparse_mmap_header(region->vbasedev->name,
region->nr, sparse->nr_areas);
region->nr_mmaps = sparse->nr_areas;
region->mmaps = g_new0(VFIOMmap, region->nr_mmaps);
for (i = 0; i < region->nr_mmaps; i++) {
region->mmaps[i].offset = sparse->areas[i].offset;
region->mmaps[i].size = sparse->areas[i].size;
trace_vfio_region_sparse_mmap_entry(i, region->mmaps[i].offset,
region->mmaps[i].offset +
region->mmaps[i].size);
}
}
int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
int index, const char *name)
{
@ -525,11 +573,14 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
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);
vfio_setup_region_sparse_mmaps(region, info);
region->mmaps[0].offset = 0;
region->mmaps[0].size = region->size;
if (!region->nr_mmaps) {
region->nr_mmaps = 1;
region->mmaps = g_new0(VFIOMmap, region->nr_mmaps);
region->mmaps[0].offset = 0;
region->mmaps[0].size = region->size;
}
}
}
@ -1089,6 +1140,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
*info = g_malloc0(argsz);
(*info)->index = index;
retry:
(*info)->argsz = argsz;
if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
@ -1096,6 +1148,13 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
return -errno;
}
if ((*info)->argsz > argsz) {
argsz = (*info)->argsz;
*info = g_realloc(*info, argsz);
goto retry;
}
return 0;
}

View File

@ -1734,6 +1734,8 @@ vfio_region_mmap(const char *name, unsigned long offset, unsigned long end) "Reg
vfio_region_exit(const char *name, int index) "Device %s, region %d"
vfio_region_finalize(const char *name, int index) "Device %s, region %d"
vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d"
vfio_region_sparse_mmap_header(const char *name, int index, int nr_areas) "Device %s region %d: %d sparse mmap entries"
vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned long end) "sparse entry %d [0x%lx - 0x%lx]"
# hw/vfio/platform.c
vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"