Update README.md

merge-requests/1/head
_xeroxz 4 years ago
parent f2a58cf04e
commit f1314b6778

@ -39,7 +39,7 @@ forward to guest controlled interrupt handlers such as #DB and interrupt handler
These stacks are used by bluepills interrupt routines. This is not required at all but I felt I should go the extra mile here and setup dedicated stacks for my interrupt handlers in the
off chance that RSP contains an invalid address when a page fault, division error, or general protection error happens.
##### GDT - Global Descriptor Table
#### GDT - Global Descriptor Table
The host GDT is 1:1 with the guest GDT except firstly, a different, host controlled page is used for each cores GDT. Secondly the TR segment base address is updated to reflect
the new TSS (which is also 1:1 with the guest TSS but on a new page).
@ -55,7 +55,7 @@ _sgdt(&gdt_value);
memcpy(vcpu->gdt, (void*)gdt_value.base_address, PAGE_SIZE);
```
##### TSS - Task State Segment
###### TSS - Task State Segment
The host TSS is 1:1 with the guest TSS except that there are additional interrupt stack table entries. When an exception happens and execution is redirected to an interrupt handler, the address
in RSP cannot ***always*** be trusted. Therefore, ***especially*** on privilege level changes, RSP will be changed with a predetermined valid stack (which is located in the TSS). However if an exception happens and there is no privilege change (say you have an exception in ring-0),
@ -90,4 +90,6 @@ vcpu->tss.interrupt_stack_table[idt::ist_idx::gp] =
vcpu->tss.interrupt_stack_table[idt::ist_idx::de] =
reinterpret_cast<u64>(ExAllocatePool(NonPagedPool,
PAGE_SIZE * HOST_STACK_PAGES)) + (PAGE_SIZE * HOST_STACK_PAGES);
```
```
#### IDT - Interrupt Descriptor Table
Loading…
Cancel
Save