When splitting leaf parent entry to smaller granularity, create
child page table before modifing parent entry. In previous code
logic, when splitting a leaf parent entry, parent entry will
point to a null 4k memory before child page table is created in
this 4k memory. When the page table to be modified is the page
table in CR3, if the executed CpuPageTableLib code is in the
range mapped by the modified leaf parent entry, then issue will
happen.
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>
Clear PageSize bit(Bit7) for non-leaf entry in PageTableLibSetPnle.
This function is used to set non-leaf entry attributes so it should
make sure that the PageSize bit of the entry should be 0.
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>
In previous code logic, when splitting a leaf parent entry to
smaller granularity child page table, if the parent entry
Attribute&Mask(without PageTableBaseAddress field) is equal to the
input attribute&mask(without PageTableBaseAddress field), the split
process won't happen. This may lead to failure in non-1:1 mapping.
For example, there is a page table in which [0, 1G] is mapped(Lv4[0]
,Lv3[0,0], a non-leaf level4 entry and a leaf level3 entry). And we
want to remap [0, 2M] linear address range to [1G, 1G + 2M] with the
same attibute. The expected behaviour should be: split Lv3[0,0]
entry into 512 level2 entries and remap the first level2 entry to
cover [0, 2M]. But the split won't happen in previous code since
PageTableBaseAddress of input Attribute is not checked.
So, when checking if a leaf parent entry needs to be splitted, we
should also check if PageTableBaseAddress calculated by parent entry
is equal to the value caculated by input attribute.
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>
Move some local variable initialization to the beginning of the
function. Also delete duplicated calculation for RegionLength.
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>
Add check for input Length in PageTableMap (). Return
RETURN_SUCCESS when input Length is 0.
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>
Remove unneeded 'if' condition in CpuPageTableLib code.
The deleted code is in the code branch for present non-leaf parent
entry. So the 'if' check for (ParentPagingEntry->Pnle.Bits.Present
== 0) is always FALSE.
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>
Support PAE paging for PageTableParse API in CpuPageTableLib.
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>
Add host based unit tests for the CpuPageTableLib services.
Unit test focuses on PageTableMap function, containing two kinds of test
cases: manual test case and random test case.
Manual test case creates some corner case to test function PageTableMap.
Random test case generates multiple random memory entries (with random
attribute) as the input of function PageTableMap to get the output
pagetable. Output pagetable will be validated and be parsed to get output
memory entries, and then the input and output memory entries will be
compared to verify the functionality.
The unit test is not perfect yet. There are options for random test, and
some of them control the test coverage, and some option are not ready.
Will enhance in the future.
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
This reverts commit 2812668bfc for tag202208.
This feature will be merged after stable tag 202208 is created.
Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Zhiguang Liu <zhiguang.liu@intel.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Add host based unit tests for the CpuPageTableLib services.
Unit test focuses on PageTableMap function, containing two kinds of test
cases: manual test case and random test case.
Manual test case creates some corner case to test function PageTableMap.
Random test case generates multiple random memory entries (with random
attribute) as the input of function PageTableMap to get the output
pagetable. Output pagetable will be validated and be parsed to get output
memory entries, and then the input and output memory entries will be
compared to verify the functionality.
The unit test is not perfect yet. There are options for random test, and
some of them control the test coverage, and some option are not ready.
Will enhance in the future.
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@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 following paging structure to map
[2M-4K, 2M] as P = 1, RW = 0,
[2M, 4M] as P = 1, RW = 1:
PML4[0] -> PDPTE[0] -> PDE[0](RW = 0) -> PTE[255](P = 0, RW = 0)
-> PDE[1](RW = 1)
When a new request to map [2M-4K, 2M+4K] as P = 1, RW = 1,
CpuPageTableMap() wrongly requests 4K buffer size for the new mapping
request.
But in fact, for [2M-4K, 2M] request, PTE[255] can be changed in place,
for [2M, 2M+4K], no change is needed because PDE[1].RW = 1 already.
The change fixes the bug.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: 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 read-only, today's logic unnecessarily changes
the paging structure in 2 aspects:
1. When setting PageTableBaseAddress in the entry, the code clears
all attributes.
2. Even the ReadWrite bit in parent entry is not set, the code clears
the ReadWrite bit in the leaf entry.
First change is wrong. It should not change other attributes when
setting the PA.
Second change is unnecessary. Because the parent entry already
declares the whole region as read-only, there is no need to clear
ReadWrite bit in the leaf entry again.
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>
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>
Today's logic wrongly treats the non-leaf entry as leaf entry and
updates its paging attributes.
The patch fixes the bug to only update paging attributes for
non-present entries or leaf entries.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
When PageTableMap() is called to create non 1:1 mapping
such as [0, 1G) to [8K, 1G+8K), it should split the page entry to the
4K page level, but old logic has a bug that it just uses 1G page
entry.
The patch fixes the bug.
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
The patch replaces
LinearAddress + Offset == RegionStart
with
((LinearAddress + Offset) & RegionMask) == 0
The replace should not cause any behavior change.
Because:
1. In first loop of while when LinearAddress + Offset == RegionStart,
because the lower "BitStart" bits of RegionStart are all-zero,
all lower "BitStart" bits of (LinearAddress + Offset) are all-zero.
Because all lower "BitStart" bits of RegionMask is all-one and
bits are all-zero, ((LinearAddress + Offset) & RegionMask) == 0.
2. In following loops of the while, even RegionStart is increased
by RegionLength, the lower "BitStart" bits are still all-zero.
So the two expressions still semantically equal to each other.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
When LinearAddress or Length is not aligned on 4KB, PageTableMap()
should return Invalid Parameter.
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-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
Liming Gao
Ray Ni