From 6f4e1405b91da0d0a1084ae3aff2bd308432778f Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 20 Jul 2020 10:25:36 +0100 Subject: 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 Message-id: 20200713213341.590275-2-richard.henderson@linaro.org Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/arm/virt.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) (limited to 'hw/arm/virt.c') diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 9005dae356..5866c4ce20 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -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); -- cgit 1.4.1