If enabled, SMM will not use on-demand paging. SMM will build static page table for all memory.
The page table size depend on 2 things: 1) The 1G paging capability. 2) The whole system memory/MMIO addressing capability. A) If the system only supports 2M paging, When the whole memory/MMIO is 32bit, we only need 1+1+4=6 pages for 4G. When the whole memory/MMIO is 39bit, we need 1+1+256 pages (~ 1M) When the whole memory/MMIO is 48bit, we need 1+256+256*256 pages (~ 257M) B) If the system supports 1G paging. When the whole memory/MMIO is 32bit, we only need 1+1+4=6 pages for 4G. (We still generate 2M page for maintenance consideration.) When the whole memory/MMIO is 39bit, we still need 6 pages. (We setup 1G paging for >1G.) When the whole memory/MMIO is 48bit, we need 1+256 pages (~ 1M). Cc: Jeff Fan <jeff....@intel.com> Cc: Feng Tian <feng.t...@intel.com> Cc: Star Zeng <star.z...@intel.com> Cc: Michael D Kinney <michael.d.kin...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Cc: Paolo Bonzini <pbonz...@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jiewen Yao <jiewen....@intel.com> --- UefiCpuPkg/UefiCpuPkg.dec | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec index 8674533..a110820 100644 --- a/UefiCpuPkg/UefiCpuPkg.dec +++ b/UefiCpuPkg/UefiCpuPkg.dec @@ -199,6 +199,14 @@ # @Prompt The specified AP target C-state for Mwait. gUefiCpuPkgTokenSpaceGuid.PcdCpuApTargetCstate|0|UINT8|0x00000007 + ## Indicates if SMM uses static page table. + # If enabled, SMM will not use on-demand paging. SMM will build static page table for all memory.<BR><BR> + # This flag only impacts X64 build, because SMM alway builds static page table for IA32. + # TRUE - SMM uses static page table for all memory.<BR> + # FALSE - SMM uses static page table for below 4G memory and use on-demand paging for above 4G memory.<BR> + # @Prompt Use static page table for all memory in SMM. + gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStaticPageTable|TRUE|BOOLEAN|0x3213210D + [PcdsDynamic, PcdsDynamicEx] ## Contains the pointer to a CPU S3 data buffer of structure ACPI_CPU_DATA. # @Prompt The pointer to a CPU S3 data buffer. -- 2.7.4.windows.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
