Description of problem:
I just boot my system from virtual manager on rhel 6.4.

Additional info:
WARNING: at lib/dma-debug.c:937 check_unmap+0x47d/0x930()
Hardware name: KVM
8139cp 0000:00:07.0: DMA-API: device driver failed to check map error[device address=0x000000001dd1b7b2] [size=90 bytes] [mapped as single]
Modules linked in: nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ebtable_filter ebtables ip6table_filter ip6_tables crc32_pclmul crc32c_intel joydev snd_hda_intel snd_hda_codec ghash_clmulni_intel snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer 8139too snd soundcore 8139cp microcode virtio_net virtio_balloon mii i2c_piix4 cirrus drm_kms_helper ttm virtio_blk drm i2c_core uinput
Pid: 621, comm: console-kit-dae Not tainted 3.9.0-0.rc7.git1.1.fc20.x86_64 #1
Call Trace:
 <IRQ>  [<ffffffff81068e46>] warn_slowpath_common+0x66/0x80
 [<ffffffff81068eac>] warn_slowpath_fmt+0x4c/0x50
 [<ffffffff8138133d>] check_unmap+0x47d/0x930
 [<ffffffff8138184f>] debug_dma_unmap_page+0x5f/0x70
 [<ffffffffa00f1915>] ? cp_interrupt+0x35/0x5b0 [8139cp]
 [<ffffffffa00f1bd0>] cp_interrupt+0x2f0/0x5b0 [8139cp]
 [<ffffffff810ace58>] ? sched_clock_cpu+0xa8/0x100
 [<ffffffff810d51fd>] ? trace_hardirqs_off+0xd/0x10
 [<ffffffff81119436>] handle_irq_event_percpu+0x56/0x390
 [<ffffffff811197ad>] handle_irq_event+0x3d/0x60
 [<ffffffff8111c96a>] handle_fasteoi_irq+0x5a/0x100
 [<ffffffff8101c36f>] handle_irq+0xbf/0x150
 [<ffffffff81073850>] ? irq_enter+0x50/0xa0
 [<ffffffff8172738d>] do_IRQ+0x4d/0xc0
 [<ffffffff8171c6b2>] common_interrupt+0x72/0x72
 <EOI>  [<ffffffff817256c5>] ? sysret_check+0x22/0x5d

Potential duplicate: bug 926009