hw/i386: Introduce X86_FW_OVMF Kconfig symbol

Introduce the X86_FW_OVMF Kconfig symbol for OVMF-specific code.
Move the OVMF-specific code from pc_sysfw.c to pc_sysfw_ovmf.c,
adding a pair of stubs.
Update MAINTAINERS to reach OVMF maintainers when these new
files are modified.

This fixes when building the microvm machine standalone:

  /usr/bin/ld: libqemu-i386-softmmu.fa.p/target_i386_monitor.c.o: in
  function `qmp_sev_inject_launch_secret':
  target/i386/monitor.c:749: undefined reference to `pc_system_ovmf_table_find'

Fixes: f522cef9b3 ("sev: update sev-inject-launch-secret to make gpa optional")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210616204328.2611406-22-philmd@redhat.com>

MAINTAINERS

@@ -2945,6 +2945,7 @@ EDK2 Firmware
 M: Laszlo Ersek <lersek@redhat.com>
 M: Philippe Mathieu-Daudé <philmd@redhat.com>
 S: Supported
+F: hw/i386/*ovmf*
 F: pc-bios/descriptors/??-edk2-*.json
 F: pc-bios/edk2-*
 F: roms/Makefile.edk2

hw/i386/Kconfig

@@ -1,5 +1,9 @@
+config X86_FW_OVMF
+    bool
+
 config SEV
     bool
+    select X86_FW_OVMF
     depends on KVM
 
 config PC

hw/i386/meson.build

@@ -24,6 +24,8 @@ i386_ss.add(when: 'CONFIG_PC', if_true: files(
   'pc_sysfw.c',
   'acpi-build.c',
   'port92.c'))
+i386_ss.add(when: 'CONFIG_X86_FW_OVMF', if_true: files('pc_sysfw_ovmf.c'),
+                                        if_false: files('pc_sysfw_ovmf-stubs.c'))
 
 subdir('kvm')
 subdir('xen')

hw/i386/pc_sysfw.c

@@ -124,129 +124,6 @@ void pc_system_flash_cleanup_unused(PCMachineState *pcms)
     }
 }
 
-#define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
-
-static bool ovmf_flash_parsed;
-static uint8_t *ovmf_table;
-static int ovmf_table_len;
-
-static void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
-{
-    uint8_t *ptr;
-    QemuUUID guid;
-    int tot_len;
-
-    /* should only be called once */
-    if (ovmf_flash_parsed) {
-        return;
-    }
-
-    ovmf_flash_parsed = true;
-
-    if (flash_size < TARGET_PAGE_SIZE) {
-        return;
-    }
-
-    /*
-     * if this is OVMF there will be a table footer
-     * guid 48 bytes before the end of the flash file.  If it's
-     * not found, silently abort the flash parsing.
-     */
-    qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
-    guid = qemu_uuid_bswap(guid); /* guids are LE */
-    ptr = flash_ptr + flash_size - 48;
-    if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
-        return;
-    }
-
-    /* if found, just before is two byte table length */
-    ptr -= sizeof(uint16_t);
-    tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
-
-    if (tot_len <= 0) {
-        return;
-    }
-
-    ovmf_table = g_malloc(tot_len);
-    ovmf_table_len = tot_len;
-
-    /*
-     * ptr is the foot of the table, so copy it all to the newly
-     * allocated ovmf_table and then set the ovmf_table pointer
-     * to the table foot
-     */
-    memcpy(ovmf_table, ptr - tot_len, tot_len);
-    ovmf_table += tot_len;
-}
-
-/**
- * pc_system_ovmf_table_find - Find the data associated with an entry in OVMF's
- * reset vector GUIDed table.
- *
- * @entry: GUID string of the entry to lookup
- * @data: Filled with a pointer to the entry's value (if not NULL)
- * @data_len: Filled with the length of the entry's value (if not NULL). Pass
- *            NULL here if the length of data is known.
- *
- * Return: true if the entry was found in the OVMF table; false otherwise.
- */
-bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
-                               int *data_len)
-{
-    uint8_t *ptr = ovmf_table;
-    int tot_len = ovmf_table_len;
-    QemuUUID entry_guid;
-
-    assert(ovmf_flash_parsed);
-
-    if (qemu_uuid_parse(entry, &entry_guid) < 0) {
-        return false;
-    }
-
-    if (!ptr) {
-        return false;
-    }
-
-    entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
-    while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
-        int len;
-        QemuUUID *guid;
-
-        /*
-         * The data structure is
-         *   arbitrary length data
-         *   2 byte length of entire entry
-         *   16 byte guid
-         */
-        guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
-        len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
-                                        sizeof(uint16_t)));
-
-        /*
-         * just in case the table is corrupt, wouldn't want to spin in
-         * the zero case
-         */
-        if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
-            return false;
-        } else if (len > tot_len) {
-            return false;
-        }
-
-        ptr -= len;
-        tot_len -= len;
-        if (qemu_uuid_is_equal(guid, &entry_guid)) {
-            if (data) {
-                *data = ptr;
-            }
-            if (data_len) {
-                *data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
-            }
-            return true;
-        }
-    }
-    return false;
-}
-
 /*
  * Map the pcms->flash[] from 4GiB downward, and realize.
  * Map them in descending order, i.e. pcms->flash[0] at the top,

hw/i386/pc_sysfw_ovmf-stubs.c

@@ -0,0 +1,26 @@
+/*
+ * QEMU PC System Firmware (OVMF stubs)
+ *
+ * Copyright (c) 2021 Red Hat, Inc.
+ *
+ * Author:
+ *   Philippe Mathieu-Daudé <philmd@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * 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 "hw/i386/pc.h"
+
+bool pc_system_ovmf_table_find(const char *entry, uint8_t **data, int *data_len)
+{
+    g_assert_not_reached();
+}
+
+void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
+{
+    g_assert_not_reached();
+}

hw/i386/pc_sysfw_ovmf.c

@@ -0,0 +1,151 @@
+/*
+ * QEMU PC System Firmware (OVMF specific)
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2011-2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/i386/pc.h"
+#include "cpu.h"
+
+#define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
+
+static bool ovmf_flash_parsed;
+static uint8_t *ovmf_table;
+static int ovmf_table_len;
+
+void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
+{
+    uint8_t *ptr;
+    QemuUUID guid;
+    int tot_len;
+
+    /* should only be called once */
+    if (ovmf_flash_parsed) {
+        return;
+    }
+
+    ovmf_flash_parsed = true;
+
+    if (flash_size < TARGET_PAGE_SIZE) {
+        return;
+    }
+
+    /*
+     * if this is OVMF there will be a table footer
+     * guid 48 bytes before the end of the flash file.  If it's
+     * not found, silently abort the flash parsing.
+     */
+    qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
+    guid = qemu_uuid_bswap(guid); /* guids are LE */
+    ptr = flash_ptr + flash_size - 48;
+    if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
+        return;
+    }
+
+    /* if found, just before is two byte table length */
+    ptr -= sizeof(uint16_t);
+    tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
+
+    if (tot_len <= 0) {
+        return;
+    }
+
+    ovmf_table = g_malloc(tot_len);
+    ovmf_table_len = tot_len;
+
+    /*
+     * ptr is the foot of the table, so copy it all to the newly
+     * allocated ovmf_table and then set the ovmf_table pointer
+     * to the table foot
+     */
+    memcpy(ovmf_table, ptr - tot_len, tot_len);
+    ovmf_table += tot_len;
+}
+
+/**
+ * pc_system_ovmf_table_find - Find the data associated with an entry in OVMF's
+ * reset vector GUIDed table.
+ *
+ * @entry: GUID string of the entry to lookup
+ * @data: Filled with a pointer to the entry's value (if not NULL)
+ * @data_len: Filled with the length of the entry's value (if not NULL). Pass
+ *            NULL here if the length of data is known.
+ *
+ * Return: true if the entry was found in the OVMF table; false otherwise.
+ */
+bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
+                               int *data_len)
+{
+    uint8_t *ptr = ovmf_table;
+    int tot_len = ovmf_table_len;
+    QemuUUID entry_guid;
+
+    assert(ovmf_flash_parsed);
+
+    if (qemu_uuid_parse(entry, &entry_guid) < 0) {
+        return false;
+    }
+
+    if (!ptr) {
+        return false;
+    }
+
+    entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
+    while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
+        int len;
+        QemuUUID *guid;
+
+        /*
+         * The data structure is
+         *   arbitrary length data
+         *   2 byte length of entire entry
+         *   16 byte guid
+         */
+        guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
+        len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
+                                        sizeof(uint16_t)));
+
+        /*
+         * just in case the table is corrupt, wouldn't want to spin in
+         * the zero case
+         */
+        if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
+            return false;
+        } else if (len > tot_len) {
+            return false;
+        }
+
+        ptr -= len;
+        tot_len -= len;
+        if (qemu_uuid_is_equal(guid, &entry_guid)) {
+            if (data) {
+                *data = ptr;
+            }
+            if (data_len) {
+                *data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
+            }
+            return true;
+        }
+    }
+    return false;
+}

include/hw/i386/pc.h

@@ -188,6 +188,7 @@ void pc_system_flash_cleanup_unused(PCMachineState *pcms);
 void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion *rom_memory);
 bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
                                int *data_len);
+void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size);
 
 
 /* acpi-build.c */