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VMM: Add support for larger pages

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getPhysical() now stops at a larger page, unmap() can unmap a larger page, but map() just transforms it into a normal page.
getFlags() larger pages support is still pending.

At least now we don't page fault because we're trying to free a larger page.
This commit is contained in:
apio 2022-10-12 14:27:26 +02:00
parent 525d567af6
commit 950f4ef608
1 changed files with 103 additions and 10 deletions
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113
kernel/src/memory/VMM.cpp
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@ -36,7 +36,17 @@ namespace Paging
{ {
return; // Already unmapped return; // Already unmapped
} }
else { PDP = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
PDE.Present = false;
PDE.LargerPages = false;
PML4->entries[PDP_i] = PDE;
goto invalidate;
}
PDP = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PDP->entries[PD_i]; PDE = PDP->entries[PD_i];
PageTable* PD; PageTable* PD;
@ -44,7 +54,17 @@ namespace Paging
{ {
return; // Already unmapped return; // Already unmapped
} }
else { PD = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
PDE.Present = false;
PDE.LargerPages = false;
PDP->entries[PD_i] = PDE;
goto invalidate;
}
PD = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PD->entries[PT_i]; PDE = PD->entries[PT_i];
PageTable* PT; PageTable* PT;
@ -52,7 +72,17 @@ namespace Paging
{ {
return; // Already unmapped return; // Already unmapped
} }
else { PT = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
PDE.LargerPages = false;
PDE.Present = false;
PD->entries[PT_i] = PDE;
goto invalidate;
}
PT = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PT->entries[P_i]; PDE = PT->entries[P_i];
PDE.Present = false; PDE.Present = false;
@ -80,7 +110,11 @@ namespace Paging
{ {
return UINT64_MAX; // Not mapped return UINT64_MAX; // Not mapped
} }
else { PDP = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages) return PDE.Address << 12 | (virtualAddress & PAGE_SIZE);
PDP = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PDP->entries[PD_i]; PDE = PDP->entries[PD_i];
PageTable* PD; PageTable* PD;
@ -88,7 +122,11 @@ namespace Paging
{ {
return UINT64_MAX; // Not mapped return UINT64_MAX; // Not mapped
} }
else { PD = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages) return PDE.Address << 12 | (virtualAddress & PAGE_SIZE);
PD = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PD->entries[PT_i]; PDE = PD->entries[PT_i];
PageTable* PT; PageTable* PT;
@ -96,10 +134,15 @@ namespace Paging
{ {
return UINT64_MAX; // Not mapped return UINT64_MAX; // Not mapped
} }
else { PT = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages) return PDE.Address << 12 | (virtualAddress & PAGE_SIZE);
PT = (PageTable*)((uint64_t)PDE.Address << 12);
}
PDE = PT->entries[P_i]; PDE = PT->entries[P_i];
return PDE.Address << 12; if (!PDE.Present) return UINT64_MAX;
return PDE.Address << 12 | (virtualAddress & PAGE_SIZE);
} }
uint64_t VirtualMemoryManager::getFlags(uint64_t virtualAddress) uint64_t VirtualMemoryManager::getFlags(uint64_t virtualAddress)
@ -173,7 +216,24 @@ namespace Paging
if (flags & User) PDE.UserSuper = true; if (flags & User) PDE.UserSuper = true;
PML4->entries[PDP_i] = PDE; PML4->entries[PDP_i] = PDE;
} }
else { PDP = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
unmap(virtualAddress);
PDE.LargerPages = false;
PML4->entries[PDP_i] = PDE;
PDP = (PageTable*)PMM::request_page();
ASSERT(!(PMM_DID_FAIL(PDP)));
memset(PDP, 0, PAGE_SIZE);
PDE.set_address((uint64_t)PDP);
PDE.Present = true;
PDE.ReadWrite = true;
if (flags & User) PDE.UserSuper = true;
return map(virtualAddress, physicalAddress, flags);
}
PDP = (PageTable*)((uint64_t)PDE.Address << 12);
}
if ((flags & User) && !PDE.UserSuper) if ((flags & User) && !PDE.UserSuper)
{ {
PDE.UserSuper = true; PDE.UserSuper = true;
@ -193,7 +253,24 @@ namespace Paging
if (flags & User) PDE.UserSuper = true; if (flags & User) PDE.UserSuper = true;
PDP->entries[PD_i] = PDE; PDP->entries[PD_i] = PDE;
} }
else { PD = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
unmap(virtualAddress);
PDE.LargerPages = false;
PDP->entries[PD_i] = PDE;
PD = (PageTable*)PMM::request_page();
ASSERT(!(PMM_DID_FAIL(PD)));
memset(PD, 0, PAGE_SIZE);
PDE.set_address((uint64_t)PD);
PDE.Present = true;
PDE.ReadWrite = true;
if (flags & User) PDE.UserSuper = true;
return map(virtualAddress, physicalAddress, flags);
}
PD = (PageTable*)((uint64_t)PDE.Address << 12);
}
if ((flags & User) && !PDE.UserSuper) if ((flags & User) && !PDE.UserSuper)
{ {
PDE.UserSuper = true; PDE.UserSuper = true;
@ -213,7 +290,23 @@ namespace Paging
if (flags & User) PDE.UserSuper = true; if (flags & User) PDE.UserSuper = true;
PD->entries[PT_i] = PDE; PD->entries[PT_i] = PDE;
} }
else { PT = (PageTable*)((uint64_t)PDE.Address << 12); } else
{
if (PDE.LargerPages)
{
unmap(virtualAddress);
PDE.LargerPages = false;
PT = (PageTable*)PMM::request_page();
ASSERT(!(PMM_DID_FAIL(PT)));
memset(PT, 0, PAGE_SIZE);
PDE.set_address((uint64_t)PT);
PDE.Present = true;
PDE.ReadWrite = true;
if (flags & User) PDE.UserSuper = true;
PD->entries[PT_i] = PDE;
}
PT = (PageTable*)((uint64_t)PDE.Address << 12);
}
if ((flags & User) && !PDE.UserSuper) if ((flags & User) && !PDE.UserSuper)
{ {
PDE.UserSuper = true; PDE.UserSuper = true;