static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBalloon *s = VIRTIO_BALLOON(vdev); VirtQueueElement elem; MemoryRegionSection section; while (virtqueue_pop(vq, &elem)) { size_t offset = 0; uint32_t pfn; while (iov_to_buf(elem.out_sg, elem.out_num, offset, &pfn, 4) == 4) { ram_addr_t pa; ram_addr_t addr; int p = virtio_ldl_p(vdev, &pfn); pa = (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT; offset += 4; /* FIXME: remove get_system_memory(), but how? */ section = memory_region_find(get_system_memory(), pa, 1); if (!int128_nz(section.size) || !memory_region_is_ram(section.mr)) continue; trace_virtio_balloon_handle_output(memory_region_name(section.mr), pa); /* Using memory_region_get_ram_ptr is bending the rules a bit, but should be OK because we only want a single page. */ addr = section.offset_within_region; balloon_page(memory_region_get_ram_ptr(section.mr) + addr, !!(vq == s->dvq)); memory_region_unref(section.mr); } virtqueue_push(vq, &elem, offset); virtio_notify(vdev, vq); } }