From 918d0de0728c3840e3c459202f9bdbcc690a5727 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Tue, 29 Oct 2024 12:54:40 +0000 Subject: arm/kvm: add support for MTE Extend the 'mte' property for the virt machine to cover KVM as well. For KVM, we don't allocate tag memory, but instead enable the capability. If MTE has been enabled, we need to disable migration, as we do not yet have a way to migrate the tags as well. Therefore, MTE will stay off with KVM unless requested explicitly. [gankulkarni: This patch is rework of commit b320e21c48 which broke TCG since it made the TCG -cpu max report the presence of MTE to the guest even if the board hadn't enabled MTE by wiring up the tag RAM. This meant that if the guest then tried to use MTE QEMU would segfault accessing the non-existent tag RAM.] Signed-off-by: Cornelia Huck Reviewed-by: Gustavo Romero Signed-off-by: Ganapatrao Kulkarni Message-id: 20241008114302.4855-1-gankulkarni@os.amperecomputing.com Signed-off-by: Peter Maydell --- hw/arm/virt.c | 72 ++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 42 insertions(+), 30 deletions(-) (limited to 'hw/arm/virt.c') diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 8b2b991d97..1a381e9a2b 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -2213,7 +2213,7 @@ static void machvirt_init(MachineState *machine) exit(1); } - if (vms->mte && (kvm_enabled() || hvf_enabled())) { + if (vms->mte && hvf_enabled()) { error_report("mach-virt: %s does not support providing " "MTE to the guest CPU", current_accel_name()); @@ -2283,39 +2283,51 @@ static void machvirt_init(MachineState *machine) } 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")) { - error_report("MTE requested, but not supported " - "by the guest CPU"); - exit(1); + if (tcg_enabled()) { + /* 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")) { + 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); + + if (vms->secure) { + secure_tag_sysmem = g_new(MemoryRegion, 1); + memory_region_init(secure_tag_sysmem, OBJECT(machine), + "secure-tag-memory", + UINT64_MAX / 32); + + /* As with ram, secure-tag takes precedence over tag. */ + memory_region_add_subregion_overlap(secure_tag_sysmem, + 0, tag_sysmem, -1); + } } - tag_sysmem = g_new(MemoryRegion, 1); - memory_region_init(tag_sysmem, OBJECT(machine), - "tag-memory", UINT64_MAX / 32); - + object_property_set_link(cpuobj, "tag-memory", + OBJECT(tag_sysmem), &error_abort); if (vms->secure) { - secure_tag_sysmem = g_new(MemoryRegion, 1); - memory_region_init(secure_tag_sysmem, OBJECT(machine), - "secure-tag-memory", UINT64_MAX / 32); - - /* As with ram, secure-tag takes precedence over tag. */ - memory_region_add_subregion_overlap(secure_tag_sysmem, 0, - tag_sysmem, -1); + object_property_set_link(cpuobj, "secure-tag-memory", + OBJECT(secure_tag_sysmem), + &error_abort); } - } - - object_property_set_link(cpuobj, "tag-memory", OBJECT(tag_sysmem), - &error_abort); - if (vms->secure) { - object_property_set_link(cpuobj, "secure-tag-memory", - OBJECT(secure_tag_sysmem), - &error_abort); + } else if (kvm_enabled()) { + if (!kvm_arm_mte_supported()) { + error_report("MTE requested, but not supported by KVM"); + exit(1); + } + kvm_arm_enable_mte(cpuobj, &error_abort); + } else { + error_report("MTE requested, but not supported "); + exit(1); } } -- cgit v1.2.3