On 23/02/16 11:05, David Vrabel wrote: > The hardware may not write the FIP/FDP fields with a XSAVE* > instruction. e.g., with XSAVEOPT/XSAVES if the state hasn't changed > or on AMD CPUs when a floating point exception is not pending. We > need to identify this case so we can correctly apply the check for > whether to save/restore FCS/FDS. > > By toggling FIP[63] we can turn the field into a non-canonical address > and check for this value after the XSAVE instruction. > > This results in smaller code with fewer branches and is more > understandable. > > Signed-off-by: David Vrabel <david.vra...@citrix.com>
For consistently, the same change in detection logic should be applied to fpu_fxsave() Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
