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Handle parent table flags in Mapper methods #114

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May 14, 2020
Merged

Handle parent table flags in Mapper methods #114

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88f882f
Mapper: Add map_to_with_table_flags method
haraldh Jan 8, 2020
4a72bc6
Mapper: Add methods to set the flags of the level 4/3/2 page tables
haraldh Apr 21, 2020
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210 changes: 185 additions & 25 deletions src/structures/paging/mapper/mapped_page_table.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -44,15 +44,18 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
page: Page<Size1GiB>,
frame: PhysFrame<Size1GiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.create_next_table(&mut p4[page.p4_index()], allocator)?;
let p3 = self.page_table_walker.create_next_table(
&mut p4[page.p4_index()],
parent_table_flags,
allocator,
)?;

if !p3[page.p3_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped(frame));
Expand All @@ -69,18 +72,23 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
page: Page<Size2MiB>,
frame: PhysFrame<Size2MiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.create_next_table(&mut p4[page.p4_index()], allocator)?;
let p2 = self
.page_table_walker
.create_next_table(&mut p3[page.p3_index()], allocator)?;
let p3 = self.page_table_walker.create_next_table(
&mut p4[page.p4_index()],
parent_table_flags,
allocator,
)?;
let p2 = self.page_table_walker.create_next_table(
&mut p3[page.p3_index()],
parent_table_flags,
allocator,
)?;

if !p2[page.p2_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped(frame));
Expand All @@ -97,21 +105,28 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
page: Page<Size4KiB>,
frame: PhysFrame<Size4KiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.create_next_table(&mut p4[page.p4_index()], allocator)?;
let p2 = self
.page_table_walker
.create_next_table(&mut p3[page.p3_index()], allocator)?;
let p1 = self
.page_table_walker
.create_next_table(&mut p2[page.p2_index()], allocator)?;
let p3 = self.page_table_walker.create_next_table(
&mut p4[page.p4_index()],
parent_table_flags,
allocator,
)?;
let p2 = self.page_table_walker.create_next_table(
&mut p3[page.p3_index()],
parent_table_flags,
allocator,
)?;
let p1 = self.page_table_walker.create_next_table(
&mut p2[page.p2_index()],
parent_table_flags,
allocator,
)?;

if !p1[page.p1_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped(frame));
Expand All @@ -124,17 +139,18 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {

impl<'a, P: PhysToVirt> Mapper<Size1GiB> for MappedPageTable<'a, P> {
#[inline]
unsafe fn map_to<A>(
unsafe fn map_to_with_table_flags<A>(
&mut self,
page: Page<Size1GiB>,
frame: PhysFrame<Size1GiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
self.map_to_1gib(page, frame, flags, allocator)
self.map_to_1gib(page, frame, flags, parent_table_flags, allocator)
}

fn unmap(
Expand Down Expand Up @@ -181,6 +197,39 @@ impl<'a, P: PhysToVirt> Mapper<Size1GiB> for MappedPageTable<'a, P> {
Ok(MapperFlush::new(page))
}

unsafe fn set_flags_p4_entry(
&mut self,
page: Page<Size1GiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p4_entry = &mut p4[page.p4_index()];

if p4_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p4_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

unsafe fn set_flags_p3_entry(
&mut self,
_page: Page<Size1GiB>,
_flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
Err(FlagUpdateError::ParentEntryHugePage)
}

unsafe fn set_flags_p2_entry(
&mut self,
_page: Page<Size1GiB>,
_flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
Err(FlagUpdateError::ParentEntryHugePage)
}

fn translate_page(&self, page: Page<Size1GiB>) -> Result<PhysFrame<Size1GiB>, TranslateError> {
let p4 = &self.level_4_table;
let p3 = self.page_table_walker.next_table(&p4[page.p4_index()])?;
Expand All @@ -198,17 +247,18 @@ impl<'a, P: PhysToVirt> Mapper<Size1GiB> for MappedPageTable<'a, P> {

impl<'a, P: PhysToVirt> Mapper<Size2MiB> for MappedPageTable<'a, P> {
#[inline]
unsafe fn map_to<A>(
unsafe fn map_to_with_table_flags<A>(
&mut self,
page: Page<Size2MiB>,
frame: PhysFrame<Size2MiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
self.map_to_2mib(page, frame, flags, allocator)
self.map_to_2mib(page, frame, flags, parent_table_flags, allocator)
}

fn unmap(
Expand Down Expand Up @@ -262,6 +312,51 @@ impl<'a, P: PhysToVirt> Mapper<Size2MiB> for MappedPageTable<'a, P> {
Ok(MapperFlush::new(page))
}

unsafe fn set_flags_p4_entry(
&mut self,
page: Page<Size2MiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p4_entry = &mut p4[page.p4_index()];

if p4_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p4_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

unsafe fn set_flags_p3_entry(
&mut self,
page: Page<Size2MiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.next_table_mut(&mut p4[page.p4_index()])?;
let p3_entry = &mut p3[page.p3_index()];

if p3_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p3_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

unsafe fn set_flags_p2_entry(
&mut self,
_page: Page<Size2MiB>,
_flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
Err(FlagUpdateError::ParentEntryHugePage)
}

fn translate_page(&self, page: Page<Size2MiB>) -> Result<PhysFrame<Size2MiB>, TranslateError> {
let p4 = &self.level_4_table;
let p3 = self.page_table_walker.next_table(&p4[page.p4_index()])?;
Expand All @@ -280,17 +375,18 @@ impl<'a, P: PhysToVirt> Mapper<Size2MiB> for MappedPageTable<'a, P> {

impl<'a, P: PhysToVirt> Mapper<Size4KiB> for MappedPageTable<'a, P> {
#[inline]
unsafe fn map_to<A>(
unsafe fn map_to_with_table_flags<A>(
&mut self,
page: Page<Size4KiB>,
frame: PhysFrame<Size4KiB>,
flags: PageTableFlags,
parent_table_flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
self.map_to_4kib(page, frame, flags, allocator)
self.map_to_4kib(page, frame, flags, parent_table_flags, allocator)
}

fn unmap(
Expand Down Expand Up @@ -344,6 +440,66 @@ impl<'a, P: PhysToVirt> Mapper<Size4KiB> for MappedPageTable<'a, P> {
Ok(MapperFlush::new(page))
}

unsafe fn set_flags_p4_entry(
&mut self,
page: Page<Size4KiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p4_entry = &mut p4[page.p4_index()];

if p4_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p4_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

unsafe fn set_flags_p3_entry(
&mut self,
page: Page<Size4KiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.next_table_mut(&mut p4[page.p4_index()])?;
let p3_entry = &mut p3[page.p3_index()];

if p3_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p3_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

unsafe fn set_flags_p2_entry(
&mut self,
page: Page<Size4KiB>,
flags: PageTableFlags,
) -> Result<MapperFlushAll, FlagUpdateError> {
let p4 = &mut self.level_4_table;
let p3 = self
.page_table_walker
.next_table_mut(&mut p4[page.p4_index()])?;
let p2 = self
.page_table_walker
.next_table_mut(&mut p3[page.p3_index()])?;
let p2_entry = &mut p2[page.p2_index()];

if p2_entry.is_unused() {
return Err(FlagUpdateError::PageNotMapped);
}

p2_entry.set_flags(flags);

Ok(MapperFlushAll::new())
}

fn translate_page(&self, page: Page<Size4KiB>) -> Result<PhysFrame<Size4KiB>, TranslateError> {
let p4 = &self.level_4_table;
let p3 = self.page_table_walker.next_table(&p4[page.p4_index()])?;
Expand Down Expand Up @@ -461,6 +617,7 @@ impl<P: PhysToVirt> PageTableWalker<P> {
fn create_next_table<'b, A>(
&self,
entry: &'b mut PageTableEntry,
insert_flags: PageTableFlags,
allocator: &mut A,
) -> Result<&'b mut PageTable, PageTableCreateError>
where
Expand All @@ -470,12 +627,15 @@ impl<P: PhysToVirt> PageTableWalker<P> {

if entry.is_unused() {
if let Some(frame) = allocator.allocate_frame() {
entry.set_frame(frame, PageTableFlags::PRESENT | PageTableFlags::WRITABLE);
entry.set_frame(frame, insert_flags);
created = true;
} else {
return Err(PageTableCreateError::FrameAllocationFailed);
}
} else {
if !insert_flags.is_empty() && !entry.flags().contains(insert_flags) {
entry.set_flags(entry.flags() | insert_flags);
}
created = false;
}

Expand Down
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