We don't have to zero the IST page

Author: fwsGonzo

lib/tinykvm/vcpu.cpp

@@ -423,8 +423,7 @@ void Machine::setup_cow_mode(const Machine* other)
 	   page tables that allow the master VM to execute code
 	   separately from its forks, while sharing a master page table. */
 	auto pml4 = memory.new_page();
-	tinykvm::page_duplicate(pml4.pmem,
-		other->memory.page_at(other->memory.physbase + PT_ADDR)); // Intentional!
+	tinykvm::page_duplicate(pml4.pmem, other->memory.page_at(other->memory.physbase + PT_ADDR));
 	memory.page_tables = pml4.addr;
 
 	/* Zero a new page for IST stack */
@@ -435,7 +434,7 @@ void Machine::setup_cow_mode(const Machine* other)
 	// stackless interrupts, to be honest. Something to think about?
 	// XXX: In theory we can avoid initializing one of these pages
 	// until the guest asks for a certain level of concurrency.
-	memory.get_writable_page(memory.physbase + IST_ADDR, PDE64_RW | PDE64_NX, true);
+	memory.get_writable_page(memory.physbase + IST_ADDR, PDE64_RW | PDE64_NX, false);
 	//memory.get_writable_page(memory.physbase + IST2_ADDR, PDE64_RW | PDE64_NX, true);
 
 	struct kvm_sregs sregs = other->get_special_registers();