This is surprisingly useful when trying to debug DMA issues.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: NArtyom Tarasenko <atar4qemu@gmail.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>