Define qapi schema for the uefi variable store state. Use it and the generated visitor helper functions to store persistent variables in JSON format on disk.
Signed-off-by: Gerd Hoffmann <kra...@redhat.com> --- hw/uefi/var-service-json.c | 194 +++++++++++++++++++++++++++++++++++++ qapi/meson.build | 1 + qapi/qapi-schema.json | 1 + qapi/uefi.json | 40 ++++++++ 4 files changed, 236 insertions(+) create mode 100644 hw/uefi/var-service-json.c create mode 100644 qapi/uefi.json diff --git a/hw/uefi/var-service-json.c b/hw/uefi/var-service-json.c new file mode 100644 index 000000000000..d8d74945bbf1 --- /dev/null +++ b/hw/uefi/var-service-json.c @@ -0,0 +1,194 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - serialize non-volatile varstore from/to json, + * using qapi + * + * tools which can read/write these json files: + * - https://gitlab.com/kraxel/virt-firmware + * - https://github.com/awslabs/python-uefivars + */ +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "sysemu/dma.h" + +#include "hw/uefi/var-service.h" + +#include "qapi/dealloc-visitor.h" +#include "qapi/qobject-input-visitor.h" +#include "qapi/qobject-output-visitor.h" +#include "qapi/qmp/qobject.h" +#include "qapi/qmp/qjson.h" +#include "qapi/qapi-types-uefi.h" +#include "qapi/qapi-visit-uefi.h" + +static UefiVarStore *uefi_vars_to_qapi(uefi_vars_state *uv) +{ + static const char hex[] = { + '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', + }; + UefiVarStore *vs; + UefiVariableList **tail; + UefiVariable *v; + QemuUUID be; + uefi_variable *var; + uint8_t *data; + unsigned int i; + + vs = g_new0(UefiVarStore, 1); + vs->version = 2; + tail = &vs->variables; + + QTAILQ_FOREACH(var, &uv->variables, next) { + if (!(var->attributes & EFI_VARIABLE_NON_VOLATILE)) { + continue; + } + + v = g_new0(UefiVariable, 1); + be = qemu_uuid_bswap(var->guid); + v->guid = qemu_uuid_unparse_strdup(&be); + v->name = uefi_ucs2_to_ascii(var->name, var->name_size); + v->attr = var->attributes; + + v->data = g_malloc(var->data_size * 2 + 1); + data = var->data; + for (i = 0; i < var->data_size * 2;) { + v->data[i++] = hex[*data >> 4]; + v->data[i++] = hex[*data & 15]; + data++; + } + v->data[i++] = 0; + + QAPI_LIST_APPEND(tail, v); + } + return vs; +} + +static unsigned parse_hexchar(char c) +{ + switch (c) { + case '0' ... '9': return c - '0'; + case 'a' ... 'f': return c - 'a' + 0xa; + case 'A' ... 'F': return c - 'A' + 0xA; + default: return 0; + } +} + +static void uefi_vars_from_qapi(uefi_vars_state *uv, UefiVarStore *vs) +{ + UefiVariableList *item; + UefiVariable *v; + QemuUUID be; + uefi_variable *var; + uint8_t *data; + size_t i, len; + + for (item = vs->variables; item != NULL; item = item->next) { + v = item->value; + + var = g_new0(uefi_variable, 1); + var->attributes = v->attr; + qemu_uuid_parse(v->guid, &be); + var->guid = qemu_uuid_bswap(be); + + len = strlen(v->name); + var->name_size = len * 2 + 2; + var->name = g_malloc(var->name_size); + for (i = 0; i <= len; i++) { + var->name[i] = v->name[i]; + } + + len = strlen(v->data); + var->data_size = len / 2; + var->data = data = g_malloc(var->data_size); + for (i = 0; i < len; i += 2) { + *(data++) = + parse_hexchar(v->data[i]) << 4 | + parse_hexchar(v->data[i + 1]); + } + + QTAILQ_INSERT_TAIL(&uv->variables, var, next); + } +} + +static GString *uefi_vars_to_json(uefi_vars_state *uv) +{ + UefiVarStore *vs = uefi_vars_to_qapi(uv); + QObject *qobj = NULL; + Visitor *v; + GString *gstr; + + v = qobject_output_visitor_new(&qobj); + if (visit_type_UefiVarStore(v, NULL, &vs, NULL)) { + visit_complete(v, &qobj); + } + visit_free(v); + qapi_free_UefiVarStore(vs); + + gstr = qobject_to_json_pretty(qobj, true); + qobject_unref(qobj); + + return gstr; +} + +void uefi_vars_json_init(uefi_vars_state *uv, Error **errp) +{ + if (uv->jsonfile) { + uv->jsonfd = qemu_create(uv->jsonfile, O_RDWR, 0666, errp); + } +} + +void uefi_vars_json_save(uefi_vars_state *uv) +{ + GString *gstr; + + if (uv->jsonfd == -1) { + return; + } + + gstr = uefi_vars_to_json(uv); + + lseek(uv->jsonfd, 0, SEEK_SET); + write(uv->jsonfd, gstr->str, gstr->len); + ftruncate(uv->jsonfd, gstr->len); + fsync(uv->jsonfd); + + g_string_free(gstr, true); +} + +void uefi_vars_json_load(uefi_vars_state *uv, Error **errp) +{ + UefiVarStore *vs; + QObject *qobj; + Visitor *v; + char *str; + size_t len; + + if (uv->jsonfd == -1) { + return; + } + + len = lseek(uv->jsonfd, 0, SEEK_END); + if (len == 0) { + return; + } + + str = g_malloc(len + 1); + lseek(uv->jsonfd, 0, SEEK_SET); + read(uv->jsonfd, str, len); + str[len] = 0; + + qobj = qobject_from_json(str, errp); + v = qobject_input_visitor_new(qobj); + visit_type_UefiVarStore(v, NULL, &vs, errp); + visit_free(v); + + if (!(*errp)) { + uefi_vars_from_qapi(uv, vs); + } + + qapi_free_UefiVarStore(vs); + qobject_unref(qobj); + g_free(str); +} diff --git a/qapi/meson.build b/qapi/meson.build index f81a37565ca7..0cd1b1e0b2d1 100644 --- a/qapi/meson.build +++ b/qapi/meson.build @@ -64,6 +64,7 @@ if have_system 'rdma', 'rocker', 'tpm', + 'uefi', ] endif if have_system or have_tools diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json index c01ec335e680..d169b4660b20 100644 --- a/qapi/qapi-schema.json +++ b/qapi/qapi-schema.json @@ -80,3 +80,4 @@ { 'include': 'virtio.json' } { 'include': 'cryptodev.json' } { 'include': 'cxl.json' } +{ 'include': 'uefi.json' } diff --git a/qapi/uefi.json b/qapi/uefi.json new file mode 100644 index 000000000000..152c4d404824 --- /dev/null +++ b/qapi/uefi.json @@ -0,0 +1,40 @@ +# -*- Mode: Python -*- +# vim: filetype=python +# + +## +# @UefiVariable: +# +# UEFI Variable +# +# @guid: variable namespace guid +# +# @name: variable name (utf-8) +# +# @attr: variable attributes +# +# @data: variable content (base64) +# +# Since: 9.0 +## +{ 'struct' : 'UefiVariable', + 'data' : { 'guid' : 'str', + 'name' : 'str', + 'attr' : 'int', + 'data' : 'str', + '*time' : 'str'}} + +## +# @UefiVarStore: +# +# UEFI Variable Store +# +# @version: 2 +# +# @variables: list of uefi variables +# +# Since: 9.0 +## +{ 'struct' : 'UefiVarStore', + 'data' : { 'version' : 'int', + 'variables' : [ 'UefiVariable' ] }} -- 2.41.0
