XSAVE_SIZE
xstate = vm_alloc_pages(vm, DIV_ROUND_UP(XSAVE_SIZE, PAGE_SIZE));
memset(addr_gva2hva(vm, xstate), 0, PAGE_SIZE * DIV_ROUND_UP(XSAVE_SIZE, PAGE_SIZE));
GUEST_ASSERT(this_cpu_property(X86_PROPERTY_XSTATE_MAX_SIZE_XCR0) <= XSAVE_SIZE);