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UefiCpuPkg/CpuDxe: Enable protection for newly added page table

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One of the functionalities of CpuDxe is to update memory paging attributes.
If page table protection is applied, it must be disabled temporarily before
any attributes update and enabled again afterwards.

This patch makes use of the same way as DxeIpl to allocate page table memory
from reserved memory pool, which helps to reduce potential "split" operation
and recursive calling of SetMemorySpaceAttributes().

Laszlo (lersek@redhat.com) did a regression test on QEMU virtual platform with
one middle version of this series patch. The details can be found at

 https://lists.01.org/pipermail/edk2-devel/2017-December/018625.html

There're a few changes after his work.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
This commit is contained in:
Jian J Wang
2017-12-12 09:16:35 +08:00
committed by Star Zeng
parent 2ac1730bf2
commit 147fd35c3e
4 changed files with 267 additions and 9 deletions
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34
UefiCpuPkg/CpuDxe/CpuPageTable.h
View File

@@ -50,6 +50,19 @@ typedef struct {
PAGE_TABLE_LIB_PAGING_CONTEXT_DATA ContextData;
} PAGE_TABLE_LIB_PAGING_CONTEXT;
#define PAGE_TABLE_POOL_ALIGNMENT BASE_2MB
#define PAGE_TABLE_POOL_UNIT_SIZE SIZE_2MB
#define PAGE_TABLE_POOL_UNIT_PAGES EFI_SIZE_TO_PAGES (PAGE_TABLE_POOL_UNIT_SIZE)
#define PAGE_TABLE_POOL_ALIGN_MASK \
(~(EFI_PHYSICAL_ADDRESS)(PAGE_TABLE_POOL_ALIGNMENT - 1))
typedef struct {
VOID *NextPool;
UINTN Offset;
UINTN FreePages;
} PAGE_TABLE_POOL;
/**
Allocates one or more 4KB pages for page table.
@@ -110,4 +123,25 @@ InitializePageTableLib (
VOID
);
/**
This API provides a way to allocate memory for page table.
This API can be called more once to allocate memory for page tables.
Allocates the number of 4KB pages of type EfiRuntimeServicesData and returns a pointer to the
allocated buffer. The buffer returned is aligned on a 4KB boundary. If Pages is 0, then NULL
is returned. If there is not enough memory remaining to satisfy the request, then NULL is
returned.
@param Pages The number of 4 KB pages to allocate.
@return A pointer to the allocated buffer or NULL if allocation fails.
**/
VOID *
EFIAPI
AllocatePageTableMemory (
IN UINTN Pages
);
#endif