On Thu, 2023-12-21 at 09:02 -0500, Yang Weijiang wrote: > Kernel dynamic xfeatures now are __ONLY__ enabled for guest fpstate, i.e., > never for normal kernel fpstate. The bits are added when guest FPU config > is initialized. Guest fpstate is allocated with fpstate->is_guest set to > %true. > > For normal fpstate, the bits should have been removed when initializes > kernel FPU config settings, WARN_ONCE() if kernel detects normal fpstate > xfeatures contains kernel dynamic xfeatures before executes xsaves. > > Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx> > Reviewed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> > --- > arch/x86/kernel/fpu/xstate.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h > index 3518fb26d06b..83ebf1e1cbb4 100644 > --- a/arch/x86/kernel/fpu/xstate.h > +++ b/arch/x86/kernel/fpu/xstate.h > @@ -185,6 +185,9 @@ static inline void os_xsave(struct fpstate *fpstate) > WARN_ON_FPU(!alternatives_patched); > xfd_validate_state(fpstate, mask, false); > > + WARN_ON_FPU(!fpstate->is_guest && > + (mask & XFEATURE_MASK_KERNEL_DYNAMIC)); > + > XSTATE_XSAVE(&fpstate->regs.xsave, lmask, hmask, err); > > /* We should never fault when copying to a kernel buffer: */ Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Best regards, Maxim Levitsky
