Reviewed-by: Star Zeng <star.z...@intel.com> -----Original Message----- From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of nkvangup Sent: Monday, April 1, 2019 4:16 PM To: edk2-devel@lists.01.org Cc: Yao, Jiewen <jiewen....@intel.com>; Dong, Eric <eric.d...@intel.com>; Laszlo Ersek <ler...@redhat.com> Subject: [edk2] [PATCH v9] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1593 For every SMI occurrence, save and restore CR2 register only when SMM on-demand paging support is enabled in 64 bit operation mode. This is not a bug but to have better improvement of code. Patch5 is updated with separate functions for Save and Restore of CR2 based on review feedback. Patch6 - Removed Global Cr2 instead used function parameter. Patch7 - Removed checking Cr2 with 0 as per feedback. Patch8 and 9 - Aligned with EDK2 Coding style. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Vanguput Narendra K <narendra.k.vangu...@intel.com> Cc: Eric Dong <eric.d...@intel.com> Cc: Ray Ni <ray...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Cc: Yao Jiewen <jiewen....@intel.com> --- UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c | 26 ++++++++++++++++++++++++++ UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 9 ++++++--- UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h | 22 ++++++++++++++++++++++ UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c | 30 ++++++++++++++++++++++++++++++ 4 files changed, 84 insertions(+), 3 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c index b734a1ea8c..d1e146a70c 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c @@ -316,3 +316,29 @@ SetPageTableAttributes ( return ; } + +/** + This function returns with no action for 32 bit. + + @param[out] *Cr2 Pointer to variable to hold CR2 register value. +**/ +VOID +SaveCr2 ( + OUT UINTN *Cr2 + ) +{ + return ; +} + +/** + This function returns with no action for 32 bit. + + @param[in] Cr2 Value to write into CR2 register. +**/ +VOID +RestoreCr2 ( + IN UINTN Cr2 + ) +{ + return ; +} diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c index 3b0b3b52ac..ce70f77709 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c @@ -1112,9 +1112,11 @@ SmiRendezvous ( ASSERT(CpuIndex < mMaxNumberOfCpus); // - // Save Cr2 because Page Fault exception in SMM may override its value + // Save Cr2 because Page Fault exception in SMM may override its + value, // when using on-demand paging for above 4G memory. // - Cr2 = AsmReadCr2 (); + Cr2 = 0; + SaveCr2 (&Cr2); // // Perform CPU specific entry hooks @@ -1253,10 +1255,11 @@ SmiRendezvous ( Exit: SmmCpuFeaturesRendezvousExit (CpuIndex); + // // Restore Cr2 // - AsmWriteCr2 (Cr2); + RestoreCr2 (Cr2); } /** diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h index 84efb22981..38f9104117 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h @@ -1243,4 +1243,26 @@ EFIAPI PiSmmCpuSmiEntryFixupAddress ( ); +/** + This function reads CR2 register when on-demand paging is enabled + for 64 bit and no action for 32 bit. + + @param[out] *Cr2 Pointer to variable to hold CR2 register value. +**/ +VOID +SaveCr2 ( + OUT UINTN *Cr2 + ); + +/** + This function writes into CR2 register when on-demand paging is +enabled + for 64 bit and no action for 32 bit. + + @param[in] Cr2 Value to write into CR2 register. +**/ +VOID +RestoreCr2 ( + IN UINTN Cr2 + ); + #endif diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c index 2c77cb47a4..95eaf0b016 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c @@ -1053,3 +1053,33 @@ SetPageTableAttributes ( return ; } + +/** + This function reads CR2 register when on-demand paging is enabled. + + @param[out] *Cr2 Pointer to variable to hold CR2 register value. +**/ +VOID +SaveCr2 ( + OUT UINTN *Cr2 + ) +{ + if (!mCpuSmmStaticPageTable) { + *Cr2 = AsmReadCr2 (); + } +} + +/** + This function restores CR2 register when on-demand paging is enabled. + + @param[in] Cr2 Value to write into CR2 register. +**/ +VOID +RestoreCr2 ( + IN UINTN Cr2 + ) +{ + if (!mCpuSmmStaticPageTable) { + AsmWriteCr2 (Cr2); + } +} -- 2.16.2.windows.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
