Modify CpuPageTableLib code to enable PAE paging.
In PageTableMap() API:
When creating new PAE page table, after creating page table,
set all MustBeZero fields of 4 PDPTE to 0. The MustBeZero
fields are treated as RW and other attributes by the common
map logic. So they might be set to 1.
When updating exsiting PAE page table, the special steps are:
1.Prepare 4K-aligned 32bytes memory in stack for 4 temp PDPTE.
2.Copy original 4 PDPTE to the 4 temp PDPTE and set the RW,
UserSupervisor to 1 and set Nx of 4 temp PDPTE to 0.
4.After updating the page table, set the MustBeZero fields of
4 temp PDPTE to 0.
5.Copy the temp PDPTE to original PDPTE.
In PageTableParse() API, also create 4 temp PDPTE in stack.
Copy original 4 PDPTE to the 4 temp PDPTE. Then set the RW,
UserSupervisor to 1 and set Nx of 4 temp PDPTE to 0. Finally
use the address of temp PDPTE as the page table address.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
The definition of IA32_MAP_ATTRIBUTE has 64 bits, and one of the bit
field PageTableBaseAddress is from bit 12 to bit 52. This means if the
compiler treats the 64bits value as two UINT32 value, the field
PageTableBaseAddress spans two UINT32 value. That's why when building in
NOOPT mode in IA32, the below issue is noticed:
unresolved external symbol __allshl
This patch fix the build failure by seperate field PageTableBaseAddress
into two fields, make sure no field spans two UINT32 value.
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Ray Ni <ray.ni@intel.com>
The change doesn't change functionality behavior.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
With the following paging structure that maps [0, 2G] with ReadWrite
bit set.
PML4[0] --> PDPTE[0] --> PDE[0-255]
\-> PDPTE[1] --> PDE[0-255]
If ReadWrite bit is cleared in PML4[0] and PageTableMap() is called
to change [0, 2M] as writable, today's logic doesn't inherit the
parent entry's attributes when determining the child entry's
attributes. It just sets the PDPTE[0].PDE[0].ReadWrite bit.
But since the PML4[0].ReadWrite is 0, [0, 2M] is still read-only.
The change fixes the bug.
If the inheritable attributes in ParentPagingEntry conflicts with the
requested attributes, let the child entries take the parent attributes
and loosen the attribute in the parent entry.
E.g.: when PDPTE[0].ReadWrite = 0 but caller wants to map [0-2MB as
ReadWrite = 1 (PDE[0].ReadWrite = 1), we need to change
PDPTE[0].ReadWrite = 1 and let all PDE[0-255].ReadWrite = 0 first.
Then change PDE[0].ReadWrite = 1.
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
The lib includes two APIs:
* PageTableMap
It creates/updates mapping from LA to PA.
The implementation only supports paging structures used in 64bit
mode now. PAE paging structure support will be added in future.
* PageTableParse
It parses the page table and returns the mapping relations in an
array of IA32_MAP_ENTRY.
It passed some stress tests. These test code will be upstreamed in
other patches following edk2 Unit Test framework.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Dun Tan
Zhiguang Liu
Ray Ni