* Re: [edk2-devel] [PATCH 1/1] OvmfPkg: Store PageTablePool in TdxWorkArea
[not found] <1712727D109677C5.26635@groups.io>
@ 2022-09-22 4:43 ` Min Xu
2022-09-23 5:43 ` Gerd Hoffmann
0 siblings, 1 reply; 4+ messages in thread
From: Min Xu @ 2022-09-22 4:43 UTC (permalink / raw)
To: devel@edk2.groups.io, Gerd Hoffmann
Cc: Aktas, Erdem, James Bottomley, Yao, Jiewen, Tom Lendacky
Hi, Gerd
Do you have any comments on this patch?
> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Min Xu
> Sent: Wednesday, September 7, 2022 10:18 AM
> To: devel@edk2.groups.io
> Cc: Xu, Min M <min.m.xu@intel.com>; Aktas, Erdem
> <erdemaktas@google.com>; Gerd Hoffmann <kraxel@redhat.com>; James
> Bottomley <jejb@linux.ibm.com>; Yao, Jiewen <jiewen.yao@intel.com>; Tom
> Lendacky <thomas.lendacky@amd.com>
> Subject: [edk2-devel] [PATCH 1/1] OvmfPkg: Store PageTablePool in
> TdxWorkArea
>
> From: Min M Xu <min.m.xu@intel.com>
>
> PeilessStartupLib is running in SEC phase. In that phase global variable is not
> allowed. So the mPageTablePool cannot be used. In stead the PageTablePool
> is stored in TdxWorkArea.
>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Min M Xu <min.m.xu@intel.com>
> ---
> OvmfPkg/Include/WorkArea.h | 1 +
> .../PeilessStartupLib/PeilessStartupLib.inf | 1 +
> .../PeilessStartupLib/X64/VirtualMemory.c | 82 +++++++++++++------
> 3 files changed, 60 insertions(+), 24 deletions(-)
>
> diff --git a/OvmfPkg/Include/WorkArea.h b/OvmfPkg/Include/WorkArea.h
> index bf56fc4a6f65..0b2fb2f8c573 100644
> --- a/OvmfPkg/Include/WorkArea.h
> +++ b/OvmfPkg/Include/WorkArea.h
> @@ -71,6 +71,7 @@ typedef struct _SEC_TDX_WORK_AREA {
> UINT32 PageTableReady;
> UINT32 Gpaw;
> UINT64 HobList;
> + UINT64 PageTablePool;
> } SEC_TDX_WORK_AREA;
>
> typedef struct _TDX_WORK_AREA {
> diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
> b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
> index def50b4b019e..eed9f27d3d01 100644
> --- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
> +++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
> @@ -88,3 +88,4 @@
>
> gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
> ## CONSUMES
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDxeMemFvBase
> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDxeMemFvSize
> + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase
> diff --git a/OvmfPkg/Library/PeilessStartupLib/X64/VirtualMemory.c
> b/OvmfPkg/Library/PeilessStartupLib/X64/VirtualMemory.c
> index 6877e521e485..7e33f044993a 100644
> --- a/OvmfPkg/Library/PeilessStartupLib/X64/VirtualMemory.c
> +++ b/OvmfPkg/Library/PeilessStartupLib/X64/VirtualMemory.c
> @@ -19,13 +19,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> #include <Guid/MemoryAllocationHob.h> #include <Register/Intel/Cpuid.h>
> #include <Library/PlatformInitLib.h>
> +#include <WorkArea.h>
> #include "PageTables.h"
>
> -//
> -// Global variable to keep track current available memory used as page table.
> -//
> -PAGE_TABLE_POOL *mPageTablePool = NULL;
> -
> UINTN mLevelShift[5] = {
> 0,
> PAGING_L1_ADDRESS_SHIFT,
> @@ -50,6 +46,32 @@ UINT64 mLevelSize[5] = {
> SIZE_512GB
> };
>
> +PAGE_TABLE_POOL *
> +GetPageTablePool (
> + VOID
> + )
> +{
> + TDX_WORK_AREA *TdxWorkArea;
> +
> + TdxWorkArea = (TDX_WORK_AREA *)(UINTN)FixedPcdGet32
> + (PcdOvmfWorkAreaBase); ASSERT (TdxWorkArea != NULL);
> +
> + return (PAGE_TABLE_POOL *)TdxWorkArea-
> >SecTdxWorkArea.PageTablePool;
> +}
> +
> +VOID
> +SetPageTablePool (
> + VOID *PageTablePool
> + )
> +{
> + TDX_WORK_AREA *TdxWorkArea;
> +
> + TdxWorkArea = (TDX_WORK_AREA *)(UINTN)FixedPcdGet32
> + (PcdOvmfWorkAreaBase); ASSERT (TdxWorkArea != NULL);
> +
> + TdxWorkArea->SecTdxWorkArea.PageTablePool =
> +(UINT64)(UINTN)PageTablePool; }
> +
> BOOLEAN
> IsSetNxForStack (
> VOID
> @@ -283,7 +305,10 @@ InitializePageTablePool (
> IN UINTN PoolPages
> )
> {
> - VOID *Buffer;
> + VOID *Buffer;
> + PAGE_TABLE_POOL *PageTablePool;
> +
> + PageTablePool = GetPageTablePool ();
>
> DEBUG ((DEBUG_INFO, "InitializePageTablePool PoolPages=%d\n",
> PoolPages));
>
> @@ -303,20 +328,21 @@ InitializePageTablePool (
> //
> // Link all pools into a list for easier track later.
> //
> - if (mPageTablePool == NULL) {
> - mPageTablePool = Buffer;
> - mPageTablePool->NextPool = mPageTablePool;
> + if (PageTablePool == NULL) {
> + PageTablePool = Buffer;
> + PageTablePool->NextPool = PageTablePool;
> + SetPageTablePool (PageTablePool);
> } else {
> - ((PAGE_TABLE_POOL *)Buffer)->NextPool = mPageTablePool->NextPool;
> - mPageTablePool->NextPool = Buffer;
> - mPageTablePool = Buffer;
> + ((PAGE_TABLE_POOL *)Buffer)->NextPool = PageTablePool->NextPool;
> + PageTablePool->NextPool = Buffer;
> + PageTablePool = Buffer;
> }
>
> //
> // Reserve one page for pool header.
> //
> - mPageTablePool->FreePages = PoolPages - 1;
> - mPageTablePool->Offset = EFI_PAGES_TO_SIZE (1);
> + PageTablePool->FreePages = PoolPages - 1;
> + PageTablePool->Offset = EFI_PAGES_TO_SIZE (1);
>
> return TRUE;
> }
> @@ -343,28 +369,33 @@ AllocatePageTableMemory (
> IN UINTN Pages
> )
> {
> - VOID *Buffer;
> + VOID *Buffer;
> + PAGE_TABLE_POOL *PageTablePool;
>
> if (Pages == 0) {
> return NULL;
> }
>
> - DEBUG ((DEBUG_INFO, "AllocatePageTableMemory. mPageTablePool=%p,
> Pages=%d\n", mPageTablePool, Pages));
> + PageTablePool = GetPageTablePool ();
> +
> + DEBUG ((DEBUG_INFO, "AllocatePageTableMemory. PageTablePool=%p,
> + Pages=%d\n", PageTablePool, Pages));
> //
> // Renew the pool if necessary.
> //
> - if ((mPageTablePool == NULL) ||
> - (Pages > mPageTablePool->FreePages))
> + if ((PageTablePool == NULL) ||
> + (Pages > PageTablePool->FreePages))
> {
> if (!InitializePageTablePool (Pages)) {
> return NULL;
> + } else {
> + PageTablePool = GetPageTablePool ();
> }
> }
>
> - Buffer = (UINT8 *)mPageTablePool + mPageTablePool->Offset;
> + Buffer = (UINT8 *)PageTablePool + PageTablePool->Offset;
>
> - mPageTablePool->Offset += EFI_PAGES_TO_SIZE (Pages);
> - mPageTablePool->FreePages -= Pages;
> + PageTablePool->Offset += EFI_PAGES_TO_SIZE (Pages);
> + PageTablePool->FreePages -= Pages;
>
> DEBUG ((
> DEBUG_INFO,
> @@ -618,10 +649,13 @@ EnablePageTableProtection (
> PAGE_TABLE_POOL *Pool;
> UINT64 PoolSize;
> EFI_PHYSICAL_ADDRESS Address;
> + PAGE_TABLE_POOL *PageTablePool;
>
> DEBUG ((DEBUG_INFO, "EnablePageTableProtection\n"));
>
> - if (mPageTablePool == NULL) {
> + PageTablePool = GetPageTablePool ();
> +
> + if (PageTablePool == NULL) {
> return;
> }
>
> @@ -632,10 +666,10 @@ EnablePageTableProtection (
> AsmWriteCr0 (AsmReadCr0 () & ~CR0_WP);
>
> //
> - // SetPageTablePoolReadOnly might update mPageTablePool. It's safer to
> + // SetPageTablePoolReadOnly might update PageTablePool. It's safer to
> // remember original one in advance.
> //
> - HeadPool = mPageTablePool;
> + HeadPool = PageTablePool;
> Pool = HeadPool;
> do {
> Address = (EFI_PHYSICAL_ADDRESS)(UINTN)Pool;
> --
> 2.29.2.windows.2
>
>
>
>
>
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