Commit b53b0f69 authored by Alex Williamson's avatar Alex Williamson
Browse files

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: default avatarAlex Williamson <alex.williamson@redhat.com>
Reviewed-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Tested-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent 2c56d06b

hw/vfio/common.c

+63 −4
Original line number Diff line number Diff line
@@ -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)

{
@@ -525,13 +573,16 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region, 
            region->flags & VFIO_REGION_INFO_FLAG_MMAP &&

            !(region->size & ~qemu_real_host_page_mask)) {



            vfio_setup_region_sparse_mmaps(region, info);



            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;

            }

        }

    }



    g_free(info);
@@ -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;

}

trace-events

+2 −0
Original line number Diff line number Diff line
@@ -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"