• Sebastian Andrzej Siewior's avatar
    x86/fpu: Update comment for __raw_xsave_addr() · 2f2fcc40
    Sebastian Andrzej Siewior authored
    The comment above __raw_xsave_addr() claims that the function does not
    work for compacted buffers and was introduced in:
    
      b8b9b6ba ("x86/fpu: Allow setting of XSAVE state")
    
    In this commit, the function was factored out of get_xsave_addr() and
    this function claims that it works with "standard format or compacted
    format of xsave area". It accesses the "xstate_comp_offsets" variable
    for the actual offset and it was introduced in commit
    
      7496d645 ("Define kernel API to get address of each state in xsave area")
    
    Based on the code (back then and now):
    - xstate_offsets holds the standard offset.
    - if compacted mode is not supported then xstate_comp_offsets gets the
      xstate_offsets copied.
    - if compacted mode is supported then xstate_comp_offsets will hold the
      offset for the compacted buffer.
    
    Based on that the function works for compacted buffers as long as the
    CPU supports it and this what we care about.
    
    Remove the "Note:" which is not accurate.
    Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Reviewed-by: default avatarRik van Riel <riel@surriel.com>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Paolo Bonzini <pbonzini@redhat.com>
    Cc: Radim Krčmář <rkrcmar@redhat.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: kvm ML <kvm@vger.kernel.org>
    Cc: x86-ml <x86@kernel.org>
    Link: https://lkml.kernel.org/r/20181128222035.2996-7-bigeasy@linutronix.de
    2f2fcc40
xstate.c 32.5 KB