KVM: selftests: Use the right memslot for code, page-tables, and data allocations

Now that kvm_vm allows specifying different memslots for code, page tables,
and data, use the appropriate memslot when making allocations in
common/libraty code. Change them accordingly:

- code (allocated by lib/elf) use the CODE memslot
- stacks, exception tables, and other core data pages (like the TSS in x86)
  use the DATA memslot
- page tables and the PGD use the PT memslot
- test data (anything allocated with vm_vaddr_alloc()) uses the TEST_DATA
  memslot

No functional change intended. All allocators keep using memslot #0.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-10-ricarkol@google.com

tools/testing/selftests/kvm/lib/riscv/processor.c

@@ -61,7 +61,8 @@ void virt_arch_pgd_alloc(struct kvm_vm *vm)
 		return;
 
 	vm->pgd = vm_phy_pages_alloc(vm, nr_pages,
-				     KVM_GUEST_PAGE_TABLE_MIN_PADDR, 0);
+				     KVM_GUEST_PAGE_TABLE_MIN_PADDR,
+				     vm->memslots[MEM_REGION_PT]);
 	vm->pgd_created = true;
 }
 
@@ -288,8 +289,9 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
 
 	stack_size = vm->page_size == 4096 ? DEFAULT_STACK_PGS * vm->page_size :
 					     vm->page_size;
-	stack_vaddr = vm_vaddr_alloc(vm, stack_size,
-				     DEFAULT_RISCV_GUEST_STACK_VADDR_MIN);
+	stack_vaddr = __vm_vaddr_alloc(vm, stack_size,
+				       DEFAULT_RISCV_GUEST_STACK_VADDR_MIN,
+				       MEM_REGION_DATA);
 
 	vcpu = __vm_vcpu_add(vm, vcpu_id);
 	riscv_vcpu_mmu_setup(vcpu);