diff options
author | Vanguput, Narendra K <narendra.k.vanguput@intel.com> | 2019-04-01 16:16:01 +0800 |
---|---|---|
committer | Eric Dong <eric.dong@intel.com> | 2019-04-04 14:00:32 +0800 |
commit | 37f9fea5b88d2aa0cc702e1b315a1b939447eb01 (patch) | |
tree | b92cc51affc7c139525c8ab838046a4fdcfdffe4 /UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c | |
parent | e4ff6349bf9ee4f3f392141374901ea4994e043e (diff) | |
download | edk2-37f9fea5b88d2aa0cc702e1b315a1b939447eb01.tar.gz edk2-37f9fea5b88d2aa0cc702e1b315a1b939447eb01.tar.bz2 edk2-37f9fea5b88d2aa0cc702e1b315a1b939447eb01.zip |
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.vanguput@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Yao Jiewen <jiewen.yao@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c')
-rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c | 30 |
1 files changed, 30 insertions, 0 deletions
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);
+ }
+}
|