Re: [Qemu-devel] [qemu RFC] qapi: add "firmware.json"

[Thomas Huth]

On 07.04.2018 02:01, Laszlo Ersek wrote:
> Add a schema that describes the properties of virtual machine firmware.
[...]
> +##
> +# @SystemFirmware:
> +#
> +# Describes a system firmware binary and any NVRAM slots that it requires.
> +#
> +# @executable: Identifies the platform firmware executable.
> +#
> +# @type: The type by which the system firmware is commonly known. This is the
> +#        main search key by which management software looks up a system
> +#        firmware image for a new domain.
> +#
> +# @targets: a non-empty list of target architectures that are capable of
> +#           executing the system firmware
> +#
> +# @sysfw-map: the mapping requirements of the system firmware binary
> +#
> +# @nvram-slots: A list of NVRAM slots that are required by the system 
> firmware.
> +#               The @slot-id field must be unique across the list. 
> Importantly,
> +#               if any @FirmwareAccess is @restricted-to-secure-context in
> +#               @sysfw-map or in any @nvram-map in @nvram-slots, then (a) the
> +#               virtual machine configuration is required to emulate the 
> secure
> +#               code execution context (as defined for @targets), and (b) the
> +#               virtual machine configuration is required to actually 
> restrict
> +#               the access in question to the secure execution context.
> +#
> +# @supports-uefi-secure-boot: Whether the system firmware implements the
> +#                             software interfaces for UEFI Secure Boot, as
> +#                             defined in the UEFI specification. If the field
> +#                             is missing, its assumed value is 'false'.
> +#
> +# @supports-amd-sev: Whether the system firmware supports running under AMD
> +#                    Secure Encrypted Virtualization, as specified in the 
> AMD64
> +#                    Architecture Programmer's Manual. If the field is 
> missing,
> +#                    its assumed value is 'false'.
> +#
> +# @supports-acpi-s3: Whether the system firmware supports S3 sleep (suspend 
> to
> +#                    RAM), as defined in the ACPI specification. If the field
> +#                    is missing, its assumed value is 'false'.
> +#
> +# @supports-acpi-s4: Whether the system firmware supports S4 hibernation
> +#                    (suspend to disk), as defined in the ACPI specification.
> +#                    If the field is missing, its assumed value is 'false'.
> +#
> +# Since: 2.13
> +#
> +# Examples:
> +#
> +# {
> +#     "executable": {
> +#         "pathname": "/usr/share/seabios/bios-256k.bin",
> +#         "description": "SeaBIOS",
> +#         "tags": [
> +#             "CONFIG_ROM_SIZE=256"
> +#         ]
> +#     },
> +#     "type": "bios",
> +#     "targets": [
> +#         "i386",
> +#         "x86_64"
> +#     ],
> +#     "sysfw-map": {
> +#         "device": "memory",
> +#         "write": "denied"
> +#     },
> +#     "supports-acpi-s3": true,
> +#     "supports-acpi-s4": true
> +# }
> +#
> +# {
> +#     "executable": {
> +#         "pathname": "/usr/share/OVMF/OVMF_CODE.secboot.fd",
> +#         "description": "OVMF with Secure Boot and SMM-protected varstore",
> +#         "tags": [
> +#             "FD_SIZE_4MB",
> +#             "IA32X64",
> +#             "SECURE_BOOT_ENABLE",
> +#             "SMM_REQUIRE"
> +#         ]
> +#     },
> +#     "type": "uefi",
> +#     "targets": [
> +#         "x86_64"
> +#     ],
> +#     "sysfw-map": {
> +#         "device": "flash",
> +#         "write": "denied"
> +#     },
> +#     "nvram-slots": [
> +#         {
> +#             "slot-id": 1,
> +#             "nvram-map" : {
> +#                 "device": "flash",
> +#                 "write": "restricted-to-secure-context"
> +#             },
> +#             "templates": [
> +#                 {
> +#                     "pathname": "/usr/share/OVMF/OVMF_VARS.fd",
> +#                     "description": "empty varstore template"
> +#                 },
> +#                 {
> +#                     "pathname": "/usr/share/OVMF/OVMF_VARS.secboot.fd",
> +#                     "description": "varstore template with the Microsoft 
> certificates enrolled for Secure Boot",
> +#                     "tags": [
> +#                         "mscerts"
> +#                     ]
> +#                 }
> +#             ]
> +#         }
> +#     ],
> +#     "supports-uefi-secure-boot": true,
> +#     "supports-amd-sev": true,
> +#     "supports-acpi-s3": true
> +# }
> +#
> +# {
> +#     "executable": {
> +#         "pathname": "/usr/share/AAVMF/AAVMF_CODE.fd",
> +#         "description": "ARM64 UEFI firmware",
> +#         "tags": [
> +#             "AARCH64"
> +#         ]
> +#     },
> +#     "type": "uefi",
> +#     "targets": [
> +#         "aarch64"
> +#     ],

Another thought: I think that "targets" field is not enough. You also
need to map firmware images to certain machines. For example, on
aarch64, the AAVMF firmware only works on the "virt" machine, but not on
"raspi2" (I guess). On ppc64, SLOF only works for "pseries", but not for
the other machines like "mac99" or "g3beige". And on x86_64, EDK2 only
works for "q35" and "pc-i440fx", but not for "isapc".

 Thomas