public inbox for devel@edk2.groups.io
 help / color / mirror / Atom feed
* [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
@ 2019-03-29  4:58 nkvangup
  2019-03-29  5:10 ` Ni, Ray
  2019-03-30 14:55 ` Zeng, Star
  0 siblings, 2 replies; 5+ messages in thread
From: nkvangup @ 2019-03-29  4:58 UTC (permalink / raw)
  To: edk2-devel
  Cc: Vanguput Narendra K, Eric Dong, Ray Ni, Laszlo Ersek, Yao Jiewen

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.

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>
---
 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..af96e42982 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[in]  *Cr2  Pointer to variable to hold CR2 register value
+**/
+VOID
+SaveCr2 (
+  UINTN  *Cr2
+  )
+{
+  return ;
+}
+
+/**
+  This function returns with no action for 32 bit.
+
+  @param[in]  Cr2  Value to write into CR2 register
+**/
+VOID
+RestoreCr2 (
+  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..c9d147c8a1 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[in]  *Cr2  Pointer to variable to hold CR2 register value
+**/
+VOID
+SaveCr2 (
+  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 (
+  UINTN  Cr2
+  );
+
 #endif
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
index 2c77cb47a4..6cb44fbbe5 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[in]  *Cr2  Pointer to variable to hold CR2 register value
+**/
+VOID
+SaveCr2 (
+  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 (
+  UINTN  Cr2
+  )
+{
+  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
+    AsmWriteCr2 (Cr2);
+  }
+}
-- 
2.16.2.windows.1



^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
  2019-03-29  4:58 [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM nkvangup
@ 2019-03-29  5:10 ` Ni, Ray
  2019-03-29  9:31   ` Vanguput, Narendra K
  2019-03-30 14:55 ` Zeng, Star
  1 sibling, 1 reply; 5+ messages in thread
From: Ni, Ray @ 2019-03-29  5:10 UTC (permalink / raw)
  To: Vanguput, Narendra K, edk2-devel@lists.01.org
  Cc: Yao, Jiewen, Dong, Eric, Laszlo Ersek

> +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {

Can the "Cr2 != 0" be removed? 

> -----Original Message-----
> From: edk2-devel <edk2-devel-bounces@lists.01.org> On Behalf Of
> nkvangup
> Sent: Friday, March 29, 2019 12:58 PM
> To: edk2-devel@lists.01.org
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Laszlo Ersek <lersek@redhat.com>
> Subject: [edk2] [PATCH v6] 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.
> 
> 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>
> ---
>  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..af96e42982 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[in]  *Cr2  Pointer to variable to hold CR2 register value **/
> +VOID
> +SaveCr2 (
> +  UINTN  *Cr2
> +  )
> +{
> +  return ;
> +}
> +
> +/**
> +  This function returns with no action for 32 bit.
> +
> +  @param[in]  Cr2  Value to write into CR2 register **/ VOID
> +RestoreCr2 (
> +  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..c9d147c8a1 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[in]  *Cr2  Pointer to variable to hold CR2 register value **/
> +VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  );
> +
>  #endif
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> index 2c77cb47a4..6cb44fbbe5 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[in]  *Cr2  Pointer to variable to hold CR2 register value **/
> +VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  )
> +{
> +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> +    AsmWriteCr2 (Cr2);
> +  }
> +}
> --
> 2.16.2.windows.1
> 
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
  2019-03-29  5:10 ` Ni, Ray
@ 2019-03-29  9:31   ` Vanguput, Narendra K
  2019-03-29  9:36     ` Ni, Ray
  0 siblings, 1 reply; 5+ messages in thread
From: Vanguput, Narendra K @ 2019-03-29  9:31 UTC (permalink / raw)
  To: Ni, Ray, edk2-devel@lists.01.org; +Cc: Yao, Jiewen, Dong, Eric, Laszlo Ersek

Hi Ray,

While programming, I thought this cannot be 0 as in SDM, it says page-fault linear address.
>> CR2 - Contains the page-fault linear address (the linear address that caused a page fault).

So added a check for 0.

Now as the function is changed like program into CR2 register based on input parameter and checking for 0 is up to caller of this function. And also we don't need to require for checking 0 means, will remove it. Please confirm.

Thanks,
Naren

-----Original Message-----
From: Ni, Ray 
Sent: Friday, March 29, 2019 10:40 AM
To: Vanguput, Narendra K <narendra.k.vanguput@intel.com>; edk2-devel@lists.01.org
Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>
Subject: RE: [edk2] [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM

> +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {

Can the "Cr2 != 0" be removed? 

> -----Original Message-----
> From: edk2-devel <edk2-devel-bounces@lists.01.org> On Behalf Of 
> nkvangup
> Sent: Friday, March 29, 2019 12:58 PM
> To: edk2-devel@lists.01.org
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric 
> <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>
> Subject: [edk2] [PATCH v6] 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.
> 
> 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>
> ---
>  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..af96e42982 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[in]  *Cr2  Pointer to variable to hold CR2 register value 
> +**/ VOID
> +SaveCr2 (
> +  UINTN  *Cr2
> +  )
> +{
> +  return ;
> +}
> +
> +/**
> +  This function returns with no action for 32 bit.
> +
> +  @param[in]  Cr2  Value to write into CR2 register **/ VOID
> +RestoreCr2 (
> +  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..c9d147c8a1 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[in]  *Cr2  Pointer to variable to hold CR2 register value 
> +**/ VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  );
> +
>  #endif
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> index 2c77cb47a4..6cb44fbbe5 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[in]  *Cr2  Pointer to variable to hold CR2 register value 
> +**/ VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  )
> +{
> +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> +    AsmWriteCr2 (Cr2);
> +  }
> +}
> --
> 2.16.2.windows.1
> 
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
  2019-03-29  9:31   ` Vanguput, Narendra K
@ 2019-03-29  9:36     ` Ni, Ray
  0 siblings, 0 replies; 5+ messages in thread
From: Ni, Ray @ 2019-03-29  9:36 UTC (permalink / raw)
  To: Vanguput, Narendra K, edk2-devel@lists.01.org
  Cc: Yao, Jiewen, Dong, Eric, Laszlo Ersek

Yes. With below "Cr2 !=0" removed from final commit, Reviewed-by: Ray Ni <ray.ni@intel.com>
> > +RestoreCr2 (
> > +  UINTN  Cr2
> > +  )
> > +{
> > +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> > +    AsmWriteCr2 (Cr2);
> > +  }
> > +}

> -----Original Message-----
> From: Vanguput, Narendra K <narendra.k.vanguput@intel.com>
> Sent: Friday, March 29, 2019 5:32 PM
> To: Ni, Ray <ray.ni@intel.com>; edk2-devel@lists.01.org
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Laszlo Ersek <lersek@redhat.com>
> Subject: RE: [edk2] [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-
> demand paging in SMM
> 
> Hi Ray,
> 
> While programming, I thought this cannot be 0 as in SDM, it says page-fault
> linear address.
> >> CR2 - Contains the page-fault linear address (the linear address that
> caused a page fault).
> 
> So added a check for 0.
> 
> Now as the function is changed like program into CR2 register based on input
> parameter and checking for 0 is up to caller of this function. And also we
> don't need to require for checking 0 means, will remove it. Please confirm.
> 
> Thanks,
> Naren
> 
> -----Original Message-----
> From: Ni, Ray
> Sent: Friday, March 29, 2019 10:40 AM
> To: Vanguput, Narendra K <narendra.k.vanguput@intel.com>; edk2-
> devel@lists.01.org
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Laszlo Ersek <lersek@redhat.com>
> Subject: RE: [edk2] [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-
> demand paging in SMM
> 
> > +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> 
> Can the "Cr2 != 0" be removed?
> 
> > -----Original Message-----
> > From: edk2-devel <edk2-devel-bounces@lists.01.org> On Behalf Of
> > nkvangup
> > Sent: Friday, March 29, 2019 12:58 PM
> > To: edk2-devel@lists.01.org
> > Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric
> > <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>
> > Subject: [edk2] [PATCH v6] 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.
> >
> > 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>
> > ---
> >  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..af96e42982 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[in]  *Cr2  Pointer to variable to hold CR2 register value
> > +**/ VOID
> > +SaveCr2 (
> > +  UINTN  *Cr2
> > +  )
> > +{
> > +  return ;
> > +}
> > +
> > +/**
> > +  This function returns with no action for 32 bit.
> > +
> > +  @param[in]  Cr2  Value to write into CR2 register **/ VOID
> > +RestoreCr2 (
> > +  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..c9d147c8a1 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[in]  *Cr2  Pointer to variable to hold CR2 register value
> > +**/ VOID
> > +SaveCr2 (
> > +  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 (
> > +  UINTN  Cr2
> > +  );
> > +
> >  #endif
> > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > index 2c77cb47a4..6cb44fbbe5 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[in]  *Cr2  Pointer to variable to hold CR2 register value
> > +**/ VOID
> > +SaveCr2 (
> > +  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 (
> > +  UINTN  Cr2
> > +  )
> > +{
> > +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> > +    AsmWriteCr2 (Cr2);
> > +  }
> > +}
> > --
> > 2.16.2.windows.1
> >
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM
  2019-03-29  4:58 [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM nkvangup
  2019-03-29  5:10 ` Ni, Ray
@ 2019-03-30 14:55 ` Zeng, Star
  1 sibling, 0 replies; 5+ messages in thread
From: Zeng, Star @ 2019-03-30 14:55 UTC (permalink / raw)
  To: Vanguput, Narendra K, edk2-devel@lists.01.org
  Cc: Yao, Jiewen, Dong, Eric, Laszlo Ersek, Zeng, Star

Not comment to functionality. But just some observations about code style.
Please check them inline.

> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> nkvangup
> Sent: Friday, March 29, 2019 12:58 PM
> To: edk2-devel@lists.01.org
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Laszlo Ersek <lersek@redhat.com>
> Subject: [edk2] [PATCH v6] 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.
> 
> 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>
> ---
>  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..af96e42982 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[in]  *Cr2  Pointer to variable to hold CR2 register value

It will be more accurate with "@param[out]" according to https://edk2-docs.gitbooks.io/edk-ii-c-coding-standards-specification/content/5_source_files/57_c_programming.html#table-9-parameter-modifiers.

Same comment is also applied to other implementation or prototype in header file.

> +**/
> +VOID
> +SaveCr2 (
> +  UINTN  *Cr2

Align with the comments above, it will be better with "OUT UINTN  *Cr2"

Same comment is also applied to other implementation or prototype in header file.

> +  )
> +{
> +  return ;
> +}
> +
> +/**
> +  This function returns with no action for 32 bit.
> +
> +  @param[in]  Cr2  Value to write into CR2 register
> +**/
> +VOID
> +RestoreCr2 (
> +  UINTN  Cr2

It will be better with "IN UINTN  Cr2".

Same comment is also applied to other implementation or prototype in header file.

Thanks,
Star

> +  )
> +{
> +  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..c9d147c8a1 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[in]  *Cr2  Pointer to variable to hold CR2 register value
> +**/
> +VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  );
> +
>  #endif
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> index 2c77cb47a4..6cb44fbbe5 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[in]  *Cr2  Pointer to variable to hold CR2 register value
> +**/
> +VOID
> +SaveCr2 (
> +  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 (
> +  UINTN  Cr2
> +  )
> +{
> +  if ((!mCpuSmmStaticPageTable) && (Cr2 != 0)) {
> +    AsmWriteCr2 (Cr2);
> +  }
> +}
> --
> 2.16.2.windows.1
> 
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-03-30 14:55 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-03-29  4:58 [PATCH v6] UefiCpuPkg\CpuSmm: Save & restore CR2 on-demand paging in SMM nkvangup
2019-03-29  5:10 ` Ni, Ray
2019-03-29  9:31   ` Vanguput, Narendra K
2019-03-29  9:36     ` Ni, Ray
2019-03-30 14:55 ` Zeng, Star

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox