Topics

[PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA


Guo Dong
 

Previous it would hang in CpuDxe if DXE drivers are dispatched above 4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue, (EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx, type = 0x%x\n", Base, Size, Type));

--
2.16.2.windows.1


Ma, Maurice
 

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above 4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx, type =
0x%x\n", Base, Size, Type));

--
2.16.2.windows.1


Patrick Rudolph
 

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is casted
to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com> wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above 4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx, type =
0x%x\n", Base, Size, Type));

--
2.16.2.windows.1





Guo Dong
 

Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit: ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit: edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Patrick
Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is casted
to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com> wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above 4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx, type =
0x%x\n", Base, Size, Type));

--
2.16.2.windows.1







Patrick Rudolph
 

Hi Guo,
I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in QEMU.
The problem seems to be here, as gdt is allocated > 4GiB:
gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

Regards,
Patrick

On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit: ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit: edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Patrick
Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is casted
to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com> wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above 4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx, type =
0x%x\n", Base, Size, Type));

--
2.16.2.windows.1







Ma, Maurice
 

Hi, Ray and Eric,

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ?
In x64 long mode, the GDT base is actually 64bit. Typecasting will zero out the high 32bit address.
To me the correct code seems to be something like:
gdtPtr.Base = (UINTN)(VOID*) gdt;

Thanks
Maurice

-----Original Message-----
From: Patrick Rudolph <patrick.rudolph@9elements.com>
Sent: Monday, February 22, 2021 7:43
To: Dong, Guo <guo.dong@intel.com>
Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>; You,
Benjamin <benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Hi Guo,
I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
QEMU.
The problem seems to be here, as gdt is allocated > 4GiB:
gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

Regards,
Patrick

On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit:
ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
Patrick Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
casted to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com>
wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above
4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
type = 0x%x\n", Base, Size, Type));

--
2.16.2.windows.1







Guo Dong
 

Hi Patrick,
Thank you for the test and root-cause the issues.
Could you try if this patch works with "gdtPtr.Base = (UINTN)(VOID*) gdt;"?
I didn't see this issue when I tested SBL with UEFI payload on QEMU and a real platform.
I guess there is something that could make AllocateRuntimePool to allocate memory below 4GB while CpuDxe is dispatched above 4GB.

Thanks,
Guo

-----Original Message-----
From: Ma, Maurice <maurice.ma@intel.com>
Sent: Monday, February 22, 2021 9:50 AM
To: Patrick Rudolph <patrick.rudolph@9elements.com>; Dong, Guo
<guo.dong@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ray
<ray.ni@intel.com>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@intel.com>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Hi, Ray and Eric,

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ?
In x64 long mode, the GDT base is actually 64bit. Typecasting will zero out the
high 32bit address.
To me the correct code seems to be something like:
gdtPtr.Base = (UINTN)(VOID*) gdt;

Thanks
Maurice
-----Original Message-----
From: Patrick Rudolph <patrick.rudolph@9elements.com>
Sent: Monday, February 22, 2021 7:43
To: Dong, Guo <guo.dong@intel.com>
Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>; You,
Benjamin <benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Hi Guo,
I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
QEMU.
The problem seems to be here, as gdt is allocated > 4GiB:
gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

Regards,
Patrick

On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit:
ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
Patrick Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
casted to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com>
wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above
4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
type = 0x%x\n", Base, Size, Type));

--
2.16.2.windows.1







Patrick Rudolph
 

Hi Guo,
I tested it and it works fine with your patch. The crash is gone.

BTW: Are there are other possible side effects with placing memory
above 4GB? Like 32bit UEFI drivers or Option ROMs malfunctioning?

Regards,
Patrick

On Mon, Feb 22, 2021 at 6:10 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Thank you for the test and root-cause the issues.
Could you try if this patch works with "gdtPtr.Base = (UINTN)(VOID*) gdt;"?
I didn't see this issue when I tested SBL with UEFI payload on QEMU and a real platform.
I guess there is something that could make AllocateRuntimePool to allocate memory below 4GB while CpuDxe is dispatched above 4GB.

Thanks,
Guo

-----Original Message-----
From: Ma, Maurice <maurice.ma@intel.com>
Sent: Monday, February 22, 2021 9:50 AM
To: Patrick Rudolph <patrick.rudolph@9elements.com>; Dong, Guo
<guo.dong@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ray
<ray.ni@intel.com>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@intel.com>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Hi, Ray and Eric,

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ?
In x64 long mode, the GDT base is actually 64bit. Typecasting will zero out the
high 32bit address.
To me the correct code seems to be something like:
gdtPtr.Base = (UINTN)(VOID*) gdt;

Thanks
Maurice
-----Original Message-----
From: Patrick Rudolph <patrick.rudolph@9elements.com>
Sent: Monday, February 22, 2021 7:43
To: Dong, Guo <guo.dong@intel.com>
Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>; You,
Benjamin <benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Hi Guo,
I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
QEMU.
The problem seems to be here, as gdt is allocated > 4GiB:
gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

Regards,
Patrick

On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit:
ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
Patrick Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
casted to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@intel.com>
wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched above
4GB.
Now remove the work around since the fixed in CpuDxe are merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
type = 0x%x\n", Base, Size, Type));

--
2.16.2.windows.1







Guo Dong
 

Great. Thanks Patrick for the quick test.

Here is my thought on the UEFI Payload works on 4GB:
UefiPayloadPkg tries to provides a generic UEFI payload impl with minimum hard-coded values.
If UEFI payload could not work since a platform specific limitation, user could change their UEFI payload to work under 4GB. E.g.
a). Mark memory above 4GB as reserved in Payload entry, and update the memory attribute (using memory test driver) later.
b). or set some memory type information PCDs

If UEFI payload has some common issue when it is dispatched above 4GB, we could apply the option B if required.

BTW, current 32bit UEFI payload is not supported, and I don't think it supports memory above 4GB.

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Patrick
Rudolph
Sent: Monday, February 22, 2021 11:06 AM
To: Dong, Guo <guo.dong@intel.com>
Cc: Ma, Maurice <maurice.ma@intel.com>; Dong, Eric <eric.dong@intel.com>;
Ni, Ray <ray.ni@intel.com>; devel@edk2.groups.io; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
4GB memory WA

Hi Guo,
I tested it and it works fine with your patch. The crash is gone.

BTW: Are there are other possible side effects with placing memory
above 4GB? Like 32bit UEFI drivers or Option ROMs malfunctioning?

Regards,
Patrick

On Mon, Feb 22, 2021 at 6:10 PM Dong, Guo <guo.dong@intel.com> wrote:


Hi Patrick,
Thank you for the test and root-cause the issues.
Could you try if this patch works with "gdtPtr.Base = (UINTN)(VOID*) gdt;"?
I didn't see this issue when I tested SBL with UEFI payload on QEMU and a
real platform.
I guess there is something that could make AllocateRuntimePool to allocate
memory below 4GB while CpuDxe is dispatched above 4GB.

Thanks,
Guo

-----Original Message-----
From: Ma, Maurice <maurice.ma@intel.com>
Sent: Monday, February 22, 2021 9:50 AM
To: Patrick Rudolph <patrick.rudolph@9elements.com>; Dong, Guo
<guo.dong@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ray
<ray.ni@intel.com>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@intel.com>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove
4GB memory WA

Hi, Ray and Eric,

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe
driver ?
In x64 long mode, the GDT base is actually 64bit. Typecasting will zero out
the
high 32bit address.
To me the correct code seems to be something like:
gdtPtr.Base = (UINTN)(VOID*) gdt;

Thanks
Maurice
-----Original Message-----
From: Patrick Rudolph <patrick.rudolph@9elements.com>
Sent: Monday, February 22, 2021 7:43
To: Dong, Guo <guo.dong@intel.com>
Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>; You,
Benjamin <benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Hi Guo,
I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
QEMU.
The problem seems to be here, as gdt is allocated > 4GiB:
gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

Regards,
Patrick

On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com>
wrote:


Hi Patrick,
Please make sure you are using latest master when testing this patch.
That issue should be fix be this patch:
UefiCpuPkg/CpuDxe: Fix boot error (commit:
ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
And there is similar fix in another place as below:
UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

Thanks,
Guo

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
Patrick Rudolph
Sent: Monday, February 22, 2021 7:04 AM
To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

This patch breaks booting on master.
In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
casted to 32bits.

Regards,
Patrick

On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice
<maurice.ma@intel.com>
wrote:

Reviewed-by: Maurice Ma <maurice.ma@intel.com>

Regards
Maurice

-----Original Message-----
From: Dong, Guo <guo.dong@intel.com>
Sent: Sunday, February 14, 2021 21:13
To: devel@edk2.groups.io
Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
<benjamin.you@intel.com>
Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
Remove 4GB memory WA

Previous it would hang in CpuDxe if DXE drivers are dispatched
above
4GB.
Now remove the work around since the fixed in CpuDxe are
merged.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
index 805f5448d9..c403b0a80a 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
@@ -40,11 +40,6 @@ MemInfoCallback (
EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

- if (Base >= BASE_4GB ) {
- // Remove tested attribute to avoid DXE core to dispatch driver
to
memory above 4GB
- Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
- }
-
BuildResourceDescriptorHob (Type, Attribue,
(EFI_PHYSICAL_ADDRESS)Base, Size);
DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
type = 0x%x\n", Base, Size, Type));

--
2.16.2.windows.1









Jeff Fan
 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 
  //
  // Get the BSP's data of GDT and IDT
  //
  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);
  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

Could Ray&Eric help me to confirm it?

Jeff

Date: 2021-02-23 00:49
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA
Hi, Ray and Eric,
 
Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 
In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.
To me the correct code seems to be something like:
gdtPtr.Base = (UINTN)(VOID*) gdt;
 
Thanks
Maurice
> -----Original Message-----
> From: Patrick Rudolph <patrick.rudolph@...>
> Sent: Monday, February 22, 2021 7:43
> To: Dong, Guo <guo.dong@...>
> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,
> Benjamin <benjamin.you@...>
> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> Remove 4GB memory WA
>
> Hi Guo,
> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
> QEMU.
> The problem seems to be here, as gdt is allocated > 4GiB:
> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;
>
> Regards,
> Patrick
>
> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:
> >
> >
> > Hi Patrick,
> > Please make sure you are using latest master when testing this patch.
> > That issue should be fix be this patch:
> > UefiCpuPkg/CpuDxe: Fix boot error (commit:
> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
> > And there is similar fix in another place as below:
> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)
> >
> > Thanks,
> > Guo
> >
> > > -----Original Message-----
> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
> > > Patrick Rudolph
> > > Sent: Monday, February 22, 2021 7:04 AM
> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>
> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin
> > > <benjamin.you@...>
> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> > > Remove 4GB memory WA
> > >
> > > This patch breaks booting on master.
> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
> > > casted to 32bits.
> > >
> > > Regards,
> > > Patrick
> > >
> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>
> wrote:
> > > >
> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>
> > > >
> > > > Regards
> > > > Maurice
> > > >
> > > > > -----Original Message-----
> > > > > From: Dong, Guo <guo.dong@...>
> > > > > Sent: Sunday, February 14, 2021 21:13
> > > > > To: devel@edk2.groups.io
> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin
> > > > > <benjamin.you@...>
> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> > > > > Remove 4GB memory WA
> > > > >
> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above
> 4GB.
> > > > > Now remove the work around since the fixed in CpuDxe are merged.
> > > > >
> > > > > Signed-off-by: Guo Dong <guo.dong@...>
> > > > > ---
> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
> > > > >  1 file changed, 5 deletions(-)
> > > > >
> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > index 805f5448d9..c403b0a80a 100644
> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (
> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;
> > > > >
> > > > > -  if (Base >= BASE_4GB ) {
> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to
> > > > > memory above 4GB
> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
> > > > > -  }
> > > > > -
> > > > >    BuildResourceDescriptorHob (Type, Attribue,
> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);
> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
> > > > > type = 0x%x\n", Base, Size, Type));
> > > > >
> > > > > --
> > > > > 2.16.2.windows.1
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> >
 
 
 
 


Ni, Ray
 

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Jeff Fan
 

Ray,

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

Thanks,
Jeff

 
From: Ni, Ray
Date: 2021-02-23 10:52
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Ni, Ray
 

But we could allocate room under 4G for GDT table directly in CpuDxe.”

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Jeff Fan
 

Ray,

BSP's GDT table is setup in CpuDxe and then MpInitLib re-uses BSP's GDT table for APs.

1, UefiCpuPkg\CpuDxe:
  gdt = AllocateRuntimePool (sizeof (GdtTemplate) + 8);
  ..... 
  gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

2, UefiCpuPkg\Library\MpInitLib\MpLib.c:

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);


3, UefiCpuPkg\Library\MpInitLib\X64\MpFuncs.nasm:
    mov        si, GdtrLocation
o32 lgdt       [cs:si]

    mov        si, IdtrLocation
o32 lidt       [cs:si]

In CpuDxe, Typecasting gdt to UINT32 is one assumption that GDT table is under 4G space.  Thus, we cannot use AllocateRuntimePool (), instead we should use AllocatePages() to make sure GDT table under 4GB space.
  gdt = 0xFFFFFFFF;
  Status = gBS->AllocatePages (
                  AllocateMaxAddress,
                  EfiRuntimeServicesData,
                  EFI_SIZE_TO_PAGES (sizeof (GdtTemplate) + 8),
                  &gdt 
                  );

Thanks,
Jeff
 

From: Ni, Ray
Date: 2021-02-23 13:21
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

But we could allocate room under 4G for GDT table directly in CpuDxe.”

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Ma, Maurice
 

Could we decouple BSP and AP GDT in early waking up stage ? 

For example, AP uses temporary GDT (below 4GB) just for mode switching.  Once AP is in the final stage,  AP can reload GDT to match BSP.  In this way, we don’t have assumption on the final GDT location.

 

Thanks

Maurice

From: Ni, Ray <ray.ni@...>
Sent: Monday, February 22, 2021 21:22
To: devel@edk2.groups.io; fanjianfeng@...; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

But we could allocate room under 4G for GDT table directly in CpuDxe.

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Ni, Ray
 

Maurice,

It’s doable 😊

I prefer to accept today’s below 4G limitation to maintain simple implementation.

 

 

Thanks,

Ray

 

From: Ma, Maurice <maurice.ma@...>
Sent: Tuesday, February 23, 2021 3:26 PM
To: Ni, Ray <ray.ni@...>; devel@edk2.groups.io; fanjianfeng@...; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Could we decouple BSP and AP GDT in early waking up stage ? 

For example, AP uses temporary GDT (below 4GB) just for mode switching.  Once AP is in the final stage,  AP can reload GDT to match BSP.  In this way, we don’t have assumption on the final GDT location.

 

Thanks

Maurice

From: Ni, Ray <ray.ni@...>
Sent: Monday, February 22, 2021 21:22
To: devel@edk2.groups.io; fanjianfeng@...; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

But we could allocate room under 4G for GDT table directly in CpuDxe.

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Ma, Maurice
 

Hi, Ray, Eric and Jeff,

 

Sure, I am OK with that too.   

 Thank you all for looking into it and provide a solution quickly. 

 

Regards

Maurice

From: Ni, Ray <ray.ni@...>
Sent: Tuesday, February 23, 2021 1:08
To: Ma, Maurice <maurice.ma@...>; devel@edk2.groups.io; fanjianfeng@...; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Maurice,

It’s doable 😊

I prefer to accept today’s below 4G limitation to maintain simple implementation.

 

 

Thanks,

Ray

 

From: Ma, Maurice <maurice.ma@...>
Sent: Tuesday, February 23, 2021 3:26 PM
To: Ni, Ray <ray.ni@...>; devel@edk2.groups.io; fanjianfeng@...; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Could we decouple BSP and AP GDT in early waking up stage ? 

For example, AP uses temporary GDT (below 4GB) just for mode switching.  Once AP is in the final stage,  AP can reload GDT to match BSP.  In this way, we don’t have assumption on the final GDT location.

 

Thanks

Maurice

From: Ni, Ray <ray.ni@...>
Sent: Monday, February 22, 2021 21:22
To: devel@edk2.groups.io; fanjianfeng@...; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

But we could allocate room under 4G for GDT table directly in CpuDxe.

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >

 

 

 

 


Ni, Ray
 

Yes! It’s a bug in CpuDxe. I agree with your proposed fix.

3233 – CpuDxe may allocate above 4GB memory for GDT (tianocore.org) was submitted to capture the potential bug.

 

 

 

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 1:44 PM
To: devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc: You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

BSP's GDT table is setup in CpuDxe and then MpInitLib re-uses BSP's GDT table for APs.

 

1, UefiCpuPkg\CpuDxe:

  gdt = AllocateRuntimePool (sizeof (GdtTemplate) + 8);

  ..... 

  gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

 

2, UefiCpuPkg\Library\MpInitLib\MpLib.c:

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

3, UefiCpuPkg\Library\MpInitLib\X64\MpFuncs.nasm:

    mov        si, GdtrLocation

o32 lgdt       [cs:si]

 

    mov        si, IdtrLocation

o32 lidt       [cs:si]

 

In CpuDxe, Typecasting gdt to UINT32 is one assumption that GDT table is under 4G space.  Thus, we cannot use AllocateRuntimePool (), instead we should use AllocatePages() to make sure GDT table under 4GB space.

  gdt = 0xFFFFFFFF;

  Status = gBS->AllocatePages (

                  AllocateMaxAddress,

                  EfiRuntimeServicesData,

                  EFI_SIZE_TO_PAGES (sizeof (GdtTemplate) + 8),

                  &gdt 

                  );

 

Thanks,

Jeff

 

From: Ni, Ray

Date: 2021-02-23 13:21

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

But we could allocate room under 4G for GDT table directly in CpuDxe.

The GDT pre-allocated is re-used by AP. Why do you suggest CpuDxe allocate GDT?

 

Thanks,

Ray

 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jeff Fan
Sent: Tuesday, February 23, 2021 11:43 AM
To:
devel@edk2.groups.io; Ni, Ray <ray.ni@...>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>
Cc:
devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

Ray,

 

Yes. You are right. Acutally, x64 IDT table cannot work correctly on protected mode. :-)

 

But for GDT location, I agree it should be located under 4G space to support AP mode changing.  But we could allocate room under 4G for GDT table directly in CpuDxe.

 

Thanks,

Jeff

 

 

From: Ni, Ray

Date: 2021-02-23 10:52

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Jeff,

You are right that BSP’s GDT and IDT tables are under 4G memory.

 

It’s because when AP wakes up, it needs the GDT for entering protected mode. AP cannot access above 4G memory without entering to long mode.

 

I do agree that the 64bit IDT is not proper for AP when entering protected mode. As long as there is no exception in the short time frame (load 64bit IDT, before entering long mode), it’s still ok.

 

Thanks,

Ray

 

From: fanjianfeng@... <fanjianfeng@...>
Sent: Tuesday, February 23, 2021 8:50 AM
To: devel <
devel@edk2.groups.io>; Ma, Maurice <maurice.ma@...>; Patrick Rudolph <patrick.rudolph@...>; Dong, Guo <guo.dong@...>; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Cc:
devel@edk2.groups.io; You, Benjamin <benjamin.you@...>
Subject: Re: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

 

we will save the current BSP's GDT and IDT for APs at first time APs are waken by BSP as below. APs will start from real mode to protected mode and then to long mode. During protected mode, BSP's GDT/IDT table are working on APs.

 

In UefiCpuPkg\Library\MpInitLib\MpLib.c, 

  //

  // Get the BSP's data of GDT and IDT

  //

  AsmReadGdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->GdtrProfile);

  AsmReadIdtr ((IA32_DESCRIPTOR *) &ExchangeInfo->IdtrProfile);

 

It seems to be one bug we have assumption on GDT table and IDT table located under 4G memory space.

 

Could Ray&Eric help me to confirm it?

 

Jeff

 

From: Ma, Maurice

Date: 2021-02-23 00:49

Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

Hi, Ray and Eric,

 

Is there any reason why the GDT base was typecast to UINT32 in CpuDxe driver ? 

In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out the high 32bit address.

To me the correct code seems to be something like:

gdtPtr.Base = (UINTN)(VOID*) gdt;

 

Thanks

Maurice

> -----Original Message-----

> From: Patrick Rudolph <patrick.rudolph@...>

> Sent: Monday, February 22, 2021 7:43

> To: Dong, Guo <guo.dong@...>

> Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>; You,

> Benjamin <benjamin.you@...>

> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> Remove 4GB memory WA

>

> Hi Guo,

> I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in

> QEMU.

> The problem seems to be here, as gdt is allocated > 4GiB:

> gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;

>

> Regards,

> Patrick

>

> On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@...> wrote:

> >

> >

> > Hi Patrick,

> > Please make sure you are using latest master when testing this patch.

> > That issue should be fix be this patch:

> > UefiCpuPkg/CpuDxe: Fix boot error (commit:

> > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)

> > And there is similar fix in another place as below:

> > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:

> > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)

> >

> > Thanks,

> > Guo

> >

> > > -----Original Message-----

> > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of

> > > Patrick Rudolph

> > > Sent: Monday, February 22, 2021 7:04 AM

> > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@...>

> > > Cc: Dong, Guo <guo.dong@...>; You, Benjamin

> > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > Remove 4GB memory WA

> > >

> > > This patch breaks booting on master.

> > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is

> > > casted to 32bits.

> > >

> > > Regards,

> > > Patrick

> > >

> > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice <maurice.ma@...>

> wrote:

> > > >

> > > > Reviewed-by:  Maurice Ma <maurice.ma@...>

> > > >

> > > > Regards

> > > > Maurice

> > > >

> > > > > -----Original Message-----

> > > > > From: Dong, Guo <guo.dong@...>

> > > > > Sent: Sunday, February 14, 2021 21:13

> > > > > To: devel@edk2.groups.io

> > > > > Cc: Ma, Maurice <maurice.ma@...>; You, Benjamin

> > > > > <benjamin.you@...>

> > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:

> > > > > Remove 4GB memory WA

> > > > >

> > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched above

> 4GB.

> > > > > Now remove the work around since the fixed in CpuDxe are merged.

> > > > >

> > > > > Signed-off-by: Guo Dong <guo.dong@...>

> > > > > ---

> > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----

> > > > >  1 file changed, 5 deletions(-)

> > > > >

> > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > index 805f5448d9..c403b0a80a 100644

> > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c

> > > > > @@ -40,11 +40,6 @@ MemInfoCallback (

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |

> > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;

> > > > >

> > > > > -  if (Base >= BASE_4GB ) {

> > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver to

> > > > > memory above 4GB

> > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;

> > > > > -  }

> > > > > -

> > > > >    BuildResourceDescriptorHob (Type, Attribue,

> > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);

> > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,

> > > > > type = 0x%x\n", Base, Size, Type));

> > > > >

> > > > > --

> > > > > 2.16.2.windows.1

> > > >

> > > >

> > > >

> > > >

> > > >

> > > >

> > >

> > >

> > >

> > >

> >