• Zachary Amsden's avatar
    [PATCH] vmi: paravirt drop udelay op · eda08b1b
    Zachary Amsden authored
    Not respecting udelay causes problems with any virtual hardware that is passed
    through to real hardware.  This can be noticed by any device that interacts
    with the real world in real time - like AP startup, which takes real time.  Or
    keyboard LEDs, which should blink in real-time.  Or floppy drives, but only
    when passed through to a real floppy controller on OSes which can't
    sufficiently buffer the floppy commands to emulate a zero latency floppy.  Or
    IDE drives, when connecting to a physical CDROM.
    
    This was mostly a hack to get the kernel to boot faster, but it introduced a
    number of misvirtualization bugs, and Alan and Pavel argued pretty strongly
    against it.  We were the only client, and now want to clean up this cruft.
    Signed-off-by: default avatarZachary Amsden <zach@vmware.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    eda08b1b
vmi.c 28.1 KB