hw/arm/virt: Enable MTE via a machine property

Control this cpu feature via a machine property, much as we do
with secure=on, since both require specialized support in the
machine setup to be functional.

Default MTE to off, since this feature implies extra overhead.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200713213341.590275-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2020-07-20 10:25:36 +01:00 committed by Peter Maydell
parent 873ec69aeb
commit 6f4e1405b9
4 changed files with 49 additions and 15 deletions

View file

@ -1837,12 +1837,19 @@ static void machvirt_init(MachineState *machine)
OBJECT(secure_sysmem), &error_abort);
}
/*
* The cpu adds the property if and only if MemTag is supported.
* If it is, we must allocate the ram to back that up.
*/
if (object_property_find(cpuobj, "tag-memory", NULL)) {
if (vms->mte) {
/* Create the memory region only once, but link to all cpus. */
if (!tag_sysmem) {
/*
* The property exists only if MemTag is supported.
* If it is, we must allocate the ram to back that up.
*/
if (!object_property_find(cpuobj, "tag-memory", NULL)) {
error_report("MTE requested, but not supported "
"by the guest CPU");
exit(1);
}
tag_sysmem = g_new(MemoryRegion, 1);
memory_region_init(tag_sysmem, OBJECT(machine),
"tag-memory", UINT64_MAX / 32);
@ -2061,6 +2068,20 @@ static void virt_set_ras(Object *obj, bool value, Error **errp)
vms->ras = value;
}
static bool virt_get_mte(Object *obj, Error **errp)
{
VirtMachineState *vms = VIRT_MACHINE(obj);
return vms->mte;
}
static void virt_set_mte(Object *obj, bool value, Error **errp)
{
VirtMachineState *vms = VIRT_MACHINE(obj);
vms->mte = value;
}
static char *virt_get_gic_version(Object *obj, Error **errp)
{
VirtMachineState *vms = VIRT_MACHINE(obj);
@ -2481,6 +2502,14 @@ static void virt_instance_init(Object *obj)
"Set on/off to enable/disable reporting host memory errors "
"to a KVM guest using ACPI and guest external abort exceptions");
/* MTE is disabled by default. */
vms->mte = false;
object_property_add_bool(obj, "mte", virt_get_mte, virt_set_mte);
object_property_set_description(obj, "mte",
"Set on/off to enable/disable emulating a "
"guest CPU which implements the ARM "
"Memory Tagging Extension");
vms->irqmap = a15irqmap;
virt_flash_create(vms);