On 15.09.2023 17:00, Andrew Cooper wrote: > ... to better explain how they're used. > > Doing so highlights that SPEC_CTRL_EXIT_TO_XEN is missing a VERW flush for the > corner case when e.g. an NMI hits late in an exit-to-guest path. > > Leave a TODO, which will be addressed in subsequent patches which arrange for > DO_COND_VERW to be safe within SPEC_CTRL_EXIT_TO_XEN. > > Signed-off-by: Andrew Cooper <[email protected]>
Reviewed-by: Jan Beulich <[email protected]> Two nits though: > @@ -233,7 +236,11 @@ > X86_FEATURE_SC_MSR_PV > .endm > > -/* Use in interrupt/exception context. May interrupt Xen or PV context. */ > +/* > + * Used after an exception or maskable interrupt, hitting Xen or PV context. > + * There will either be a guest speculation context, or (baring fatal Isn't this "barring"? > @@ -260,7 +270,13 @@ > .endm > > /* > - * Use in IST interrupt/exception context. May interrupt Xen or PV context. > + * Used after an IST entry hitting Xen or PV context. Special care is > needed, > + * because when hitting Xen context, there may not a well-formed speculation Missing "be"? Jan
