Function xen_hvm_init_hypercall_stubs

freebsd/x86/xen/hvm.c:168–204

* Allocate and fill in the hypcall page. */

 * Allocate and fill in the hypcall page.
 */
int
xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type)
{
	uint32_t regs[4];

	/* Legacy PVH will get here without the cpuid leaf being set. */
	if (cpuid_base == 0)
		cpuid_base = xen_hvm_cpuid_base();
	if (cpuid_base == 0)
		return (ENXIO);

	if (xen_domain() && init_type == XEN_HVM_INIT_LATE) {
		/*
		 * If the domain type is already set we can assume that the
		 * hypercall page has been populated too, so just print the
		 * version (and apply any quirks) and exit.
		 */
		hypervisor_version();
		return 0;
	}

	if (init_type == XEN_HVM_INIT_LATE)
		hypervisor_version();

	/*
	 * Find the hypercall pages.
	 */
	do_cpuid(cpuid_base + 2, regs);
	if (regs[0] != 1)
		return (EINVAL);

	wrmsr(regs[1], (init_type == XEN_HVM_INIT_EARLY)
	    ? ((vm_paddr_t)&hypercall_page - KERNBASE)
	    : vtophys(&hypercall_page));

	return (0);
}

static void
xen_hvm_init_shared_info_page(void)