diff options
Diffstat (limited to 'hw/acpi/vmgenid.c')
| -rw-r--r-- | hw/acpi/vmgenid.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c new file mode 100644 index 0000000000..744f2847da --- /dev/null +++ b/hw/acpi/vmgenid.c @@ -0,0 +1,258 @@ +/* + * Virtual Machine Generation ID Device + * + * Copyright (C) 2017 Skyport Systems. + * + * Author: Ben Warren <ben@skyportsystems.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "qmp-commands.h" +#include "hw/acpi/acpi.h" +#include "hw/acpi/aml-build.h" +#include "hw/acpi/vmgenid.h" +#include "hw/nvram/fw_cfg.h" +#include "sysemu/sysemu.h" + +void vmgenid_build_acpi(VmGenIdState *vms, GArray *table_data, GArray *guid, + BIOSLinker *linker) +{ + Aml *ssdt, *dev, *scope, *method, *addr, *if_ctx; + uint32_t vgia_offset; + QemuUUID guid_le; + + /* Fill in the GUID values. These need to be converted to little-endian + * first, since that's what the guest expects + */ + g_array_set_size(guid, VMGENID_FW_CFG_SIZE - ARRAY_SIZE(guid_le.data)); + guid_le = vms->guid; + qemu_uuid_bswap(&guid_le); + /* The GUID is written at a fixed offset into the fw_cfg file + * in order to implement the "OVMF SDT Header probe suppressor" + * see docs/specs/vmgenid.txt for more details + */ + g_array_insert_vals(guid, VMGENID_GUID_OFFSET, guid_le.data, + ARRAY_SIZE(guid_le.data)); + + /* Put this in a separate SSDT table */ + ssdt = init_aml_allocator(); + + /* Reserve space for header */ + acpi_data_push(ssdt->buf, sizeof(AcpiTableHeader)); + + /* Storage for the GUID address */ + vgia_offset = table_data->len + + build_append_named_dword(ssdt->buf, "VGIA"); + scope = aml_scope("\\_SB"); + dev = aml_device("VGEN"); + aml_append(dev, aml_name_decl("_HID", aml_string("QEMUVGID"))); + aml_append(dev, aml_name_decl("_CID", aml_string("VM_Gen_Counter"))); + aml_append(dev, aml_name_decl("_DDN", aml_string("VM_Gen_Counter"))); + + /* Simple status method to check that address is linked and non-zero */ + method = aml_method("_STA", 0, AML_NOTSERIALIZED); + addr = aml_local(0); + aml_append(method, aml_store(aml_int(0xf), addr)); + if_ctx = aml_if(aml_equal(aml_name("VGIA"), aml_int(0))); + aml_append(if_ctx, aml_store(aml_int(0), addr)); + aml_append(method, if_ctx); + aml_append(method, aml_return(addr)); + aml_append(dev, method); + + /* the ADDR method returns two 32-bit words representing the lower and + * upper halves * of the physical address of the fw_cfg blob + * (holding the GUID) + */ + method = aml_method("ADDR", 0, AML_NOTSERIALIZED); + + addr = aml_local(0); + aml_append(method, aml_store(aml_package(2), addr)); + + aml_append(method, aml_store(aml_add(aml_name("VGIA"), + aml_int(VMGENID_GUID_OFFSET), NULL), + aml_index(addr, aml_int(0)))); + aml_append(method, aml_store(aml_int(0), aml_index(addr, aml_int(1)))); + aml_append(method, aml_return(addr)); + + aml_append(dev, method); + aml_append(scope, dev); + aml_append(ssdt, scope); + + /* attach an ACPI notify */ + method = aml_method("\\_GPE._E05", 0, AML_NOTSERIALIZED); + aml_append(method, aml_notify(aml_name("\\_SB.VGEN"), aml_int(0x80))); + aml_append(ssdt, method); + + g_array_append_vals(table_data, ssdt->buf->data, ssdt->buf->len); + + /* Allocate guest memory for the Data fw_cfg blob */ + bios_linker_loader_alloc(linker, VMGENID_GUID_FW_CFG_FILE, guid, 4096, + false /* page boundary, high memory */); + + /* Patch address of GUID fw_cfg blob into the ADDR fw_cfg blob + * so QEMU can write the GUID there. The address is expected to be + * < 4GB, but write 64 bits anyway. + * The address that is patched in is offset in order to implement + * the "OVMF SDT Header probe suppressor" + * see docs/specs/vmgenid.txt for more details. + */ + bios_linker_loader_write_pointer(linker, + VMGENID_ADDR_FW_CFG_FILE, 0, sizeof(uint64_t), + VMGENID_GUID_FW_CFG_FILE, VMGENID_GUID_OFFSET); + + /* Patch address of GUID fw_cfg blob into the AML so OSPM can retrieve + * and read it. Note that while we provide storage for 64 bits, only + * the least-signficant 32 get patched into AML. + */ + bios_linker_loader_add_pointer(linker, + ACPI_BUILD_TABLE_FILE, vgia_offset, sizeof(uint32_t), + VMGENID_GUID_FW_CFG_FILE, 0); + + build_header(linker, table_data, + (void *)(table_data->data + table_data->len - ssdt->buf->len), + "SSDT", ssdt->buf->len, 1, NULL, "VMGENID"); + free_aml_allocator(); +} + +void vmgenid_add_fw_cfg(VmGenIdState *vms, FWCfgState *s, GArray *guid) +{ + /* Create a read-only fw_cfg file for GUID */ + fw_cfg_add_file(s, VMGENID_GUID_FW_CFG_FILE, guid->data, + VMGENID_FW_CFG_SIZE); + /* Create a read-write fw_cfg file for Address */ + fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL, + vms->vmgenid_addr_le, + ARRAY_SIZE(vms->vmgenid_addr_le), false); +} + +static void vmgenid_update_guest(VmGenIdState *vms) +{ + Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL); + uint32_t vmgenid_addr; + QemuUUID guid_le; + + if (obj) { + /* Write the GUID to guest memory */ + memcpy(&vmgenid_addr, vms->vmgenid_addr_le, sizeof(vmgenid_addr)); + vmgenid_addr = le32_to_cpu(vmgenid_addr); + /* A zero value in vmgenid_addr means that BIOS has not yet written + * the address + */ + if (vmgenid_addr) { + /* QemuUUID has the first three words as big-endian, and expect + * that any GUIDs passed in will always be BE. The guest, + * however, will expect the fields to be little-endian. + * Perform a byte swap immediately before writing. + */ + guid_le = vms->guid; + qemu_uuid_bswap(&guid_le); + /* The GUID is written at a fixed offset into the fw_cfg file + * in order to implement the "OVMF SDT Header probe suppressor" + * see docs/specs/vmgenid.txt for more details. + */ + cpu_physical_memory_write(vmgenid_addr, guid_le.data, + sizeof(guid_le.data)); + /* Send _GPE.E05 event */ + acpi_send_event(DEVICE(obj), ACPI_VMGENID_CHANGE_STATUS); + } + } +} + +static void vmgenid_set_guid(Object *obj, const char *value, Error **errp) +{ + VmGenIdState *vms = VMGENID(obj); + + if (!strcmp(value, "auto")) { + qemu_uuid_generate(&vms->guid); + } else if (qemu_uuid_parse(value, &vms->guid) < 0) { + error_setg(errp, "'%s. %s': Failed to parse GUID string: %s", + object_get_typename(OBJECT(vms)), VMGENID_GUID, value); + return; + } + + vmgenid_update_guest(vms); +} + +/* After restoring an image, we need to update the guest memory and notify + * it of a potential change to VM Generation ID + */ +static int vmgenid_post_load(void *opaque, int version_id) +{ + VmGenIdState *vms = opaque; + vmgenid_update_guest(vms); + return 0; +} + +static const VMStateDescription vmstate_vmgenid = { + .name = "vmgenid", + .version_id = 1, + .minimum_version_id = 1, + .post_load = vmgenid_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY(vmgenid_addr_le, VmGenIdState, sizeof(uint64_t)), + VMSTATE_END_OF_LIST() + }, +}; + +static void vmgenid_handle_reset(void *opaque) +{ + VmGenIdState *vms = VMGENID(opaque); + /* Clear the guest-allocated GUID address when the VM resets */ + memset(vms->vmgenid_addr_le, 0, ARRAY_SIZE(vms->vmgenid_addr_le)); +} + +static void vmgenid_realize(DeviceState *dev, Error **errp) +{ + VmGenIdState *vms = VMGENID(dev); + qemu_register_reset(vmgenid_handle_reset, vms); +} + +static void vmgenid_device_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->vmsd = &vmstate_vmgenid; + dc->realize = vmgenid_realize; + dc->hotpluggable = false; + + object_class_property_add_str(klass, VMGENID_GUID, NULL, + vmgenid_set_guid, NULL); + object_class_property_set_description(klass, VMGENID_GUID, + "Set Global Unique Identifier " + "(big-endian) or auto for random value", + NULL); +} + +static const TypeInfo vmgenid_device_info = { + .name = VMGENID_DEVICE, + .parent = TYPE_DEVICE, + .instance_size = sizeof(VmGenIdState), + .class_init = vmgenid_device_class_init, +}; + +static void vmgenid_register_types(void) +{ + type_register_static(&vmgenid_device_info); +} + +type_init(vmgenid_register_types) + +GuidInfo *qmp_query_vm_generation_id(Error **errp) +{ + GuidInfo *info; + VmGenIdState *vms; + Object *obj = find_vmgenid_dev(); + + if (!obj) { + return NULL; + } + vms = VMGENID(obj); + + info = g_malloc0(sizeof(*info)); + info->guid = qemu_uuid_unparse_strdup(&vms->guid); + return info; +} |