Intel VTD: Ignore USB RMRR for HVM guest
USB controller RMRR (0xed000 - 0xeffff) conflicts with HVM guest bios
region. Setting identity mapping for it will cover the guest bios
region in p2m table. This causes system crash.
As VT-d spec says, USB controller RMRR is used in case of DMA
performed by a USB controller under BIOS SMM control for legacy
keyboard emulation. Whereas, current guest BIOS doesn't support
emulating stardand Keyboard/mouse, and it also doesn't support SMM
mode. Actually it is no chance to use USB controller RMRR now.
This patch ignores the USB controller RMRR for HVM guest.
Signed-off-by: Weidong Han <weidong.han@intel.com>
projects / xen.git / commit