On 07/31/15 14:22, Star Zeng wrote: > This feature is added for UEFI spec that says > "Stack may be marked as non-executable in identity mapped page tables". > A PCD PcdSetNxForStack is added to turn on/off this feature, and it is > FALSE by default. > > Cc: Jiewen Yao <jiewen....@intel.com> > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Star Zeng <star.z...@intel.com> > --- > MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf | 3 +- > MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c | 185 > ++++++++++++++++++++++- > MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c | 10 +- > MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c | 160 +++++++++++++++++--- > MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h | 61 +++++++- > MdeModulePkg/MdeModulePkg.dec | 11 +- > MdeModulePkg/MdeModulePkg.uni | Bin 166792 -> 168862 bytes > 7 files changed, 392 insertions(+), 38 deletions(-)
I tried to enable this feature in the OvmfPkg builds (all three of them). Unfortunately, I have found that a non-executable DXE stack breaks the EFI_MP_SERVICE_PROTOCOL.StartupAllAPs() function. (Which is provided by "UefiCpuPkg/CpuDxe/CpuMp.c".) The virtual machine is re-set when that function is called. I presume the starup code for the APs resides in an area that happens to be marked non-executable (if this feature enabled), and that causes a fatal fault or some such when the APs get the startup IPI. Thanks Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
