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UefiCpuPkg: Reduce and optimize access to attribute 

This commit is to reduce and optimize access to
attribute in CpuPageTableLib.

Unreasonable writing to attribute of page table may
leads to expection.
The assembly code for C code Pnle->Bits.Present =
Attribute->Bits.Present looks like:
   and dword [rcx], 0xfffffffe
   and eax, 0x1
   or [rcx], eax
In case Pnle->Bits.Present and Attribute->Bits.Present
is 1, Pnle->Bits.Present will be set to 0 for short
time(2 instructions) which is unexpected. If some other
core is accessing the page, it may leads to expection.
This change reduce and optimize access to attribute of
page table, attribute of page table is set only when it
need to be changed.

Signed-off-by: Zhou Jianfeng <jianfeng.zhou@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Zhou Jianfeng 2024-02-02 22:20:09 +08:00 committed by mergify[bot]
parent 056b4bf74b
commit 30a25f2778
1 changed files with 53 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
View File

@ -26,52 +26,59 @@ PageTableLibSetPte4K (
IN IA32_MAP_ATTRIBUTE *Mask
)
{
IA32_PTE_4K LocalPte4K;
LocalPte4K.Uint64 = Pte4K->Uint64;
if (Mask->Bits.PageTableBaseAddressLow || Mask->Bits.PageTableBaseAddressHigh) {
Pte4K->Uint64 = (IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (Attribute) + Offset) | (Pte4K->Uint64 & ~IA32_PE_BASE_ADDRESS_MASK_40);
LocalPte4K.Uint64 = (IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (Attribute) + Offset) | (Pte4K->Uint64 & ~IA32_PE_BASE_ADDRESS_MASK_40);
}
if (Mask->Bits.Present) {
Pte4K->Bits.Present = Attribute->Bits.Present;
LocalPte4K.Bits.Present = Attribute->Bits.Present;
}
if (Mask->Bits.ReadWrite) {
Pte4K->Bits.ReadWrite = Attribute->Bits.ReadWrite;
LocalPte4K.Bits.ReadWrite = Attribute->Bits.ReadWrite;
}
if (Mask->Bits.UserSupervisor) {
Pte4K->Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
LocalPte4K.Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
}
if (Mask->Bits.WriteThrough) {
Pte4K->Bits.WriteThrough = Attribute->Bits.WriteThrough;
LocalPte4K.Bits.WriteThrough = Attribute->Bits.WriteThrough;
}
if (Mask->Bits.CacheDisabled) {
Pte4K->Bits.CacheDisabled = Attribute->Bits.CacheDisabled;
LocalPte4K.Bits.CacheDisabled = Attribute->Bits.CacheDisabled;
}
if (Mask->Bits.Accessed) {
Pte4K->Bits.Accessed = Attribute->Bits.Accessed;
LocalPte4K.Bits.Accessed = Attribute->Bits.Accessed;
}
if (Mask->Bits.Dirty) {
Pte4K->Bits.Dirty = Attribute->Bits.Dirty;
LocalPte4K.Bits.Dirty = Attribute->Bits.Dirty;
}
if (Mask->Bits.Pat) {
Pte4K->Bits.Pat = Attribute->Bits.Pat;
LocalPte4K.Bits.Pat = Attribute->Bits.Pat;
}
if (Mask->Bits.Global) {
Pte4K->Bits.Global = Attribute->Bits.Global;
LocalPte4K.Bits.Global = Attribute->Bits.Global;
}
if (Mask->Bits.ProtectionKey) {
Pte4K->Bits.ProtectionKey = Attribute->Bits.ProtectionKey;
LocalPte4K.Bits.ProtectionKey = Attribute->Bits.ProtectionKey;
}
if (Mask->Bits.Nx) {
Pte4K->Bits.Nx = Attribute->Bits.Nx;
LocalPte4K.Bits.Nx = Attribute->Bits.Nx;
}
if (Pte4K->Uint64 != LocalPte4K.Uint64) {
Pte4K->Uint64 = LocalPte4K.Uint64;
}
}
@ -93,54 +100,61 @@ PageTableLibSetPleB (
IN IA32_MAP_ATTRIBUTE *Mask
)
{
IA32_PAGE_LEAF_ENTRY_BIG_PAGESIZE LocalPleB;
LocalPleB.Uint64 = PleB->Uint64;
if (Mask->Bits.PageTableBaseAddressLow || Mask->Bits.PageTableBaseAddressHigh) {
PleB->Uint64 = (IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (Attribute) + Offset) | (PleB->Uint64 & ~IA32_PE_BASE_ADDRESS_MASK_39);
LocalPleB.Uint64 = (IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (Attribute) + Offset) | (PleB->Uint64 & ~IA32_PE_BASE_ADDRESS_MASK_39);
}
PleB->Bits.MustBeOne = 1;
LocalPleB.Bits.MustBeOne = 1;
if (Mask->Bits.Present) {
PleB->Bits.Present = Attribute->Bits.Present;
LocalPleB.Bits.Present = Attribute->Bits.Present;
}
if (Mask->Bits.ReadWrite) {
PleB->Bits.ReadWrite = Attribute->Bits.ReadWrite;
LocalPleB.Bits.ReadWrite = Attribute->Bits.ReadWrite;
}
if (Mask->Bits.UserSupervisor) {
PleB->Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
LocalPleB.Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
}
if (Mask->Bits.WriteThrough) {
PleB->Bits.WriteThrough = Attribute->Bits.WriteThrough;
LocalPleB.Bits.WriteThrough = Attribute->Bits.WriteThrough;
}
if (Mask->Bits.CacheDisabled) {
PleB->Bits.CacheDisabled = Attribute->Bits.CacheDisabled;
LocalPleB.Bits.CacheDisabled = Attribute->Bits.CacheDisabled;
}
if (Mask->Bits.Accessed) {
PleB->Bits.Accessed = Attribute->Bits.Accessed;
LocalPleB.Bits.Accessed = Attribute->Bits.Accessed;
}
if (Mask->Bits.Dirty) {
PleB->Bits.Dirty = Attribute->Bits.Dirty;
LocalPleB.Bits.Dirty = Attribute->Bits.Dirty;
}
if (Mask->Bits.Pat) {
PleB->Bits.Pat = Attribute->Bits.Pat;
LocalPleB.Bits.Pat = Attribute->Bits.Pat;
}
if (Mask->Bits.Global) {
PleB->Bits.Global = Attribute->Bits.Global;
LocalPleB.Bits.Global = Attribute->Bits.Global;
}
if (Mask->Bits.ProtectionKey) {
PleB->Bits.ProtectionKey = Attribute->Bits.ProtectionKey;
LocalPleB.Bits.ProtectionKey = Attribute->Bits.ProtectionKey;
}
if (Mask->Bits.Nx) {
PleB->Bits.Nx = Attribute->Bits.Nx;
LocalPleB.Bits.Nx = Attribute->Bits.Nx;
}
if (PleB->Uint64 != LocalPleB.Uint64) {
PleB->Uint64 = LocalPleB.Uint64;
}
}
@ -186,24 +200,27 @@ PageTableLibSetPnle (
IN IA32_MAP_ATTRIBUTE *Mask
)
{
IA32_PAGE_NON_LEAF_ENTRY LocalPnle;
LocalPnle.Uint64 = Pnle->Uint64;
if (Mask->Bits.Present) {
Pnle->Bits.Present = Attribute->Bits.Present;
LocalPnle.Bits.Present = Attribute->Bits.Present;
}
if (Mask->Bits.ReadWrite) {
Pnle->Bits.ReadWrite = Attribute->Bits.ReadWrite;
LocalPnle.Bits.ReadWrite = Attribute->Bits.ReadWrite;
}
if (Mask->Bits.UserSupervisor) {
Pnle->Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
LocalPnle.Bits.UserSupervisor = Attribute->Bits.UserSupervisor;
}
if (Mask->Bits.Nx) {
Pnle->Bits.Nx = Attribute->Bits.Nx;
LocalPnle.Bits.Nx = Attribute->Bits.Nx;
}
Pnle->Bits.Accessed = 0;
Pnle->Bits.MustBeZero = 0;
LocalPnle.Bits.Accessed = 0;
LocalPnle.Bits.MustBeZero = 0;
//
// Set the attributes (WT, CD, A) to 0.
@ -211,8 +228,11 @@ PageTableLibSetPnle (
// So, it implictly requires PAT[0] is Write Back.
// Create a new parameter if caller requires to use a different memory type for accessing page directories.
//
Pnle->Bits.WriteThrough = 0;
Pnle->Bits.CacheDisabled = 0;
LocalPnle.Bits.WriteThrough = 0;
LocalPnle.Bits.CacheDisabled = 0;
if (Pnle->Uint64 != LocalPnle.Uint64) {
Pnle->Uint64 = LocalPnle.Uint64;
}
}
/**