The Block Event Interrupt (BEI) bit in the TRB descriptor could
delay the triggering of interrupt. For most OSes, the native
driver for xHCI will use this bit to optimize the IO performence,
due to reduction of number of interrupts.
But in Linux, the native xHCI driver for Intel brand controller
doesn't use this bit. It is fine for the native scenario due to
most work is completed by hardware. But in virtualization scenario,
it is almost impossible to support heavy data IO such as high
resolution video recording (ISOC transfer).
Hence, this issue is solved by a 'quirk' when the intel hardware is
emulated (when vendor id is set as 0x8086). For other cases, a
virtal hardware called 'ACRN xHCI' is emulated, and both Linux and
Windows will use BEI bit by default.
Tracked-On: #3628
Signed-off-by: Xiaoguang Wu <xiaoguang.wu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
7cb45bc968