Messages in this thread | | | Date | Wed, 7 Sep 2022 09:22:45 -0700 | From | Davidlohr Bueso <> | Subject | Re: [PATCH -next] memregion: Add arch_flush_memregion() interface |
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On Wed, 07 Sep 2022, Borislav Petkov wrote:
>On Mon, Aug 29, 2022 at 02:29:18PM -0700, Davidlohr Bueso wrote: >> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c >> index 1abd5438f126..18463cb704fb 100644 >> --- a/arch/x86/mm/pat/set_memory.c >> +++ b/arch/x86/mm/pat/set_memory.c >> @@ -330,6 +330,20 @@ void arch_invalidate_pmem(void *addr, size_t size) >> EXPORT_SYMBOL_GPL(arch_invalidate_pmem); >> #endif >> >> +#ifdef CONFIG_ARCH_HAS_MEMREGION_INVALIDATE >> +bool arch_has_flush_memregion(void) >> +{ >> + return !cpu_feature_enabled(X86_FEATURE_HYPERVISOR); > >This looks really weird. Why does this need to care about HV at all?
So the context here is:
e2efb6359e62 ("ACPICA: Avoid cache flush inside virtual machines")
> >Does that nfit stuff even run in guests?
No, nor does cxl. This was mostly in general a precautionary check such that the api is unavailable in VMs.
> >> +EXPORT_SYMBOL(arch_has_flush_memregion); > >... > >> +EXPORT_SYMBOL(arch_flush_memregion); > >Why aren't those exports _GPL?
Fine by me.
Thanks, Davidlohr
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