On 15 November 2017 at 21:57, Laszlo Ersek <[email protected]> wrote: > This allows the PEI core to report the maximum temporary SEC/PEI stack > usage on the DEBUG_INFO level, in the PeiCheckAndSwitchStack() function > [MdeModulePkg/Core/Pei/Dispatcher/Dispatcher.c]: > > * Normal boot: > >> Temp Stack : BaseAddress=0x814000 Length=0x4000 >> Temp Heap : BaseAddress=0x810000 Length=0x4000 >> Total temporary memory: 32768 bytes. >> temporary memory stack ever used: 5080 bytes. <---- >> temporary memory heap used for HobList: 8080 bytes. >> temporary memory heap occupied by memory pages: 0 bytes. > > * S3 resume (no SMM / PEI decompression) > >> Temp Stack : BaseAddress=0x814000 Length=0x4000 >> Temp Heap : BaseAddress=0x810000 Length=0x4000 >> Total temporary memory: 32768 bytes. >> temporary memory stack ever used: 5048 bytes. <---- >> temporary memory heap used for HobList: 7112 bytes. >> temporary memory heap occupied by memory pages: 0 bytes. > > I unit-tested this change by transitorily adding an infinite loop right > after the "rep stosq", and dumping the guest's temp SEC/PEI RAM (32KB > currently) while the guest was stuck in the loop. The dump includes one > dword from before and after the temp SEC/PEI RAM: > >> $ virsh qemu-monitor-command GUEST_NAME --hmp 'xp /8194wx 0x80FFFC' >> >> 000000000080fffc: 0x00000000 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 >> 000000000081000c: 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 >> ... >> 0000000000817fec: 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 0x5aa55aa5 >> 0000000000817ffc: 0x5aa55aa5 0x00000000 > > Cc: Ard Biesheuvel <[email protected]> > Cc: Jordan Justen <[email protected]> > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=747 > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Laszlo Ersek <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]> > --- > > Notes: > v2: > - update comment on ES [Jordan] > - document the other segment registers too [Jordan] > - move seeding to top of routine, for consistency with the IA32 version > - replace runtime right shift with compile-time division [Jordan] > - compose qword-to-write at compile-time, not at runtime > - drop Ard's Reviewed-by > > OvmfPkg/Sec/X64/SecEntry.nasm | 21 ++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/OvmfPkg/Sec/X64/SecEntry.nasm b/OvmfPkg/Sec/X64/SecEntry.nasm > index f40427aa8e04..7c55032ac962 100644 > --- a/OvmfPkg/Sec/X64/SecEntry.nasm > +++ b/OvmfPkg/Sec/X64/SecEntry.nasm > @@ -30,12 +30,33 @@ extern ASM_PFX(SecCoreStartupWithStack) > ; @param[in] RAX Initial value of the EAX register (BIST: Built-in Self > Test) > ; @param[in] DI 'BP': boot-strap processor, or 'AP': application > processor > ; @param[in] RBP Pointer to the start of the Boot Firmware Volume > +; @param[in] DS Selector allowing flat access to all addresses > +; @param[in] ES Selector allowing flat access to all addresses > +; @param[in] FS Selector allowing flat access to all addresses > +; @param[in] GS Selector allowing flat access to all addresses > +; @param[in] SS Selector allowing flat access to all addresses > ; > ; @return None This routine does not return > ; > global ASM_PFX(_ModuleEntryPoint) > ASM_PFX(_ModuleEntryPoint): > > + ; > + ; Fill the temporary RAM with the initial stack value. > + ; The loop below will seed the heap as well, but that's harmless. > + ; > + mov rax, (FixedPcdGet32 ( \ > + PcdInitValueInTempStack \ > + ) << 32) | \ > + FixedPcdGet32 (PcdInitValueInTempStack) ; qword to > store > + mov rdi, FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) ; base address, > + ; relative to > + ; ES > + mov rcx, FixedPcdGet32 (PcdOvmfSecPeiTempRamSize) / 8 ; qword count > + cld ; store from > base > + ; up > + rep stosq > + > ; > ; Load temporary RAM stack based on PCDs > ; > -- > 2.14.1.3.gb7cf6e02401b > > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
