On Wed, Feb 24, 2016 at 8:20 AM, Borislav Petkov <[email protected]> wrote: > On Wed, Feb 24, 2016 at 02:10:46PM +0000, Matt Fleming wrote: >> > Normally, the only pages with are _PAGE_GLOBAL are those that are in >> > the normal kernel mappings (swapper_pg_dir and normal mm_struct pgds). >> > By allowing _PAGE_GLOBAL to be set in EFI mappings, you're breaking >> > that convention, which forces you to use extra-expensive >> > __flush_tlb_all calls in efi_call_virt. > > Hold on, do you mean the __flush_tlb_all() in the CONFIG_EFI_MIXED code? > > That's mixed mode. I think you mean the FLUSH_TLB_ALL in efi_call. > That's EFI on 64-bit but that is mandated by the spec, AFAIR.
I mean the one in efi_call_virt. Why would the spec mandate a TLB flush at all? EFI runtime services have no business touching the paging structures directly. Heck, the 32-bit ones don't even know the *format* of the paging structures. > > So the EFI runtime crap should not change once it is mapped. And those > should be global. It is only natural. Why is it natural? Long-term, I'd rather see EFI runtime services use an actual mm_struct and use_mm. --Andy
