On 11.10.2022 18:02, Roger Pau Monne wrote: > @@ -2365,12 +2365,6 @@ On hardware supporting STIBP (Single Thread Indirect > Branch Predictors), the > By default, Xen will use STIBP when IBRS is in use (IBRS implies STIBP), and > when hardware hints recommend using it as a blanket setting. > > -On hardware supporting SSBD (Speculative Store Bypass Disable), the `ssbd=` > -option can be used to force or prevent Xen using the feature itself.
Why would we want to take away this level of control? Shouldn't we turn this on while in Xen if so requested? Which would then either mean enabling it on VMEXIT if a guest has it off, or running with it turned on using the OR of guest and host settings. Jan
