On 03.08.2025 11:47, Penny Zheng wrote: > We have PG_log_dirty flag to wrap codes about paging log-dirty support. > The main entry is paging_domctl(),
Yet paging_domctl() serves other paging modes, too. In fact for the shim PG_SH_forced is actually a mode that could plausibly come into use (even if not by way of a toolstack requesting it). It was previously indicated that it was wrong for SHADOW_PAGING to be forced off in shim-exclusive mode. No patch ever surfaced, but that may want sorting before any new boundaries are to be drawn. In fact, ... > --- a/xen/arch/x86/include/asm/paging.h > +++ b/xen/arch/x86/include/asm/paging.h > @@ -55,7 +55,7 @@ > #define PG_translate 0 > #define PG_external 0 > #endif > -#if defined(CONFIG_HVM) || !defined(CONFIG_PV_SHIM_EXCLUSIVE) > +#if defined(CONFIG_HVM) > /* Enable log dirty mode */ > #define PG_log_dirty (XEN_DOMCTL_SHADOW_ENABLE_LOG_DIRTY << PG_mode_shift) ... the conditional here likely wants to become #if defined(CONFIG_HVM) || defined(CONFIG_SHADOW_PAGING) instead. This might actually be a far more isolated change then, still moving you in the direction that you want (I think). > --- a/xen/arch/x86/mm/hap/hap.c > +++ b/xen/arch/x86/mm/hap/hap.c > @@ -189,6 +189,7 @@ out: > return rc; > } > > +#if PG_log_dirty > /************************************************/ > /* HAP LOG DIRTY SUPPORT */ > /************************************************/ > @@ -254,6 +255,7 @@ static void cf_check hap_clean_dirty_bitmap(struct domain > *d) > p2m_change_entry_type_global(d, p2m_ram_rw, p2m_ram_logdirty); > guest_flush_tlb_mask(d, d->dirty_cpumask); > } > +#endif /* PG_log_dirty */ Please also don't go overboard with #ifdef-ary: Files built for HVM=y only don't need these, as HVM=y implies non-zero PG_log_dirty. But maybe, with the other change that I outlined, you won't even need all of this anymore. Jan
