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Diffstat (limited to 'hw/acpi/bios-linker-loader.c')
| -rw-r--r-- | hw/acpi/bios-linker-loader.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/hw/acpi/bios-linker-loader.c b/hw/acpi/bios-linker-loader.c new file mode 100644 index 000000000..108061828 --- /dev/null +++ b/hw/acpi/bios-linker-loader.c @@ -0,0 +1,351 @@ +/* Dynamic linker/loader of ACPI tables + * + * Copyright (C) 2013 Red Hat Inc + * + * Author: Michael S. Tsirkin <mst@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "hw/acpi/bios-linker-loader.h" +#include "hw/nvram/fw_cfg.h" + +#include "qemu/bswap.h" + +/* + * Linker/loader is a paravirtualized interface that passes commands to guest. + * The commands can be used to request guest to + * - allocate memory chunks and initialize them from QEMU FW CFG files + * - link allocated chunks by storing pointer to one chunk into another + * - calculate ACPI checksum of part of the chunk and store into same chunk + */ +#define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH + +struct BiosLinkerLoaderEntry { + uint32_t command; + union { + /* + * COMMAND_ALLOCATE - allocate a table from @alloc.file + * subject to @alloc.align alignment (must be power of 2) + * and @alloc.zone (can be HIGH or FSEG) requirements. + * + * Must appear exactly once for each file, and before + * this file is referenced by any other command. + */ + struct { + char file[BIOS_LINKER_LOADER_FILESZ]; + uint32_t align; + uint8_t zone; + } alloc; + + /* + * COMMAND_ADD_POINTER - patch the table (originating from + * @dest_file) at @pointer.offset, by adding a pointer to the table + * originating from @src_file. 1,2,4 or 8 byte unsigned + * addition is used depending on @pointer.size. + */ + struct { + char dest_file[BIOS_LINKER_LOADER_FILESZ]; + char src_file[BIOS_LINKER_LOADER_FILESZ]; + uint32_t offset; + uint8_t size; + } pointer; + + /* + * COMMAND_ADD_CHECKSUM - calculate checksum of the range specified by + * @cksum_start and @cksum_length fields, + * and then add the value at @cksum.offset. + * Checksum simply sums -X for each byte X in the range + * using 8-bit math. + */ + struct { + char file[BIOS_LINKER_LOADER_FILESZ]; + uint32_t offset; + uint32_t start; + uint32_t length; + } cksum; + + /* + * COMMAND_WRITE_POINTER - write the fw_cfg file (originating from + * @dest_file) at @wr_pointer.offset, by adding a pointer to + * @src_offset within the table originating from @src_file. + * 1,2,4 or 8 byte unsigned addition is used depending on + * @wr_pointer.size. + */ + struct { + char dest_file[BIOS_LINKER_LOADER_FILESZ]; + char src_file[BIOS_LINKER_LOADER_FILESZ]; + uint32_t dst_offset; + uint32_t src_offset; + uint8_t size; + } wr_pointer; + + /* padding */ + char pad[124]; + }; +} QEMU_PACKED; +typedef struct BiosLinkerLoaderEntry BiosLinkerLoaderEntry; + +enum { + BIOS_LINKER_LOADER_COMMAND_ALLOCATE = 0x1, + BIOS_LINKER_LOADER_COMMAND_ADD_POINTER = 0x2, + BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3, + BIOS_LINKER_LOADER_COMMAND_WRITE_POINTER = 0x4, +}; + +enum { + BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1, + BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2, +}; + +/* + * BiosLinkerFileEntry: + * + * An internal type used for book-keeping file entries + */ +typedef struct BiosLinkerFileEntry { + char *name; /* file name */ + GArray *blob; /* data accosiated with @name */ +} BiosLinkerFileEntry; + +/* + * bios_linker_loader_init: allocate a new linker object instance. + * + * After initialization, linker commands can be added, and will + * be stored in the linker.cmd_blob array. + */ +BIOSLinker *bios_linker_loader_init(void) +{ + BIOSLinker *linker = g_new(BIOSLinker, 1); + + linker->cmd_blob = g_array_new(false, true /* clear */, 1); + linker->file_list = g_array_new(false, true /* clear */, + sizeof(BiosLinkerFileEntry)); + return linker; +} + +/* Free linker wrapper */ +void bios_linker_loader_cleanup(BIOSLinker *linker) +{ + int i; + BiosLinkerFileEntry *entry; + + g_array_free(linker->cmd_blob, true); + + for (i = 0; i < linker->file_list->len; i++) { + entry = &g_array_index(linker->file_list, BiosLinkerFileEntry, i); + g_free(entry->name); + } + g_array_free(linker->file_list, true); + g_free(linker); +} + +static const BiosLinkerFileEntry * +bios_linker_find_file(const BIOSLinker *linker, const char *name) +{ + int i; + BiosLinkerFileEntry *entry; + + for (i = 0; i < linker->file_list->len; i++) { + entry = &g_array_index(linker->file_list, BiosLinkerFileEntry, i); + if (!strcmp(entry->name, name)) { + return entry; + } + } + return NULL; +} + +/* + * board code must realize fw_cfg first, as a fixed device, before + * another device realize function call bios_linker_loader_can_write_pointer() + */ +bool bios_linker_loader_can_write_pointer(void) +{ + FWCfgState *fw_cfg = fw_cfg_find(); + return fw_cfg && fw_cfg_dma_enabled(fw_cfg); +} + +/* + * bios_linker_loader_alloc: ask guest to load file into guest memory. + * + * @linker: linker object instance + * @file_name: name of the file blob to be loaded + * @file_blob: pointer to blob corresponding to @file_name + * @alloc_align: required minimal alignment in bytes. Must be a power of 2. + * @alloc_fseg: request allocation in FSEG zone (useful for the RSDP ACPI table) + * + * Note: this command must precede any other linker command using this file. + */ +void bios_linker_loader_alloc(BIOSLinker *linker, + const char *file_name, + GArray *file_blob, + uint32_t alloc_align, + bool alloc_fseg) +{ + BiosLinkerLoaderEntry entry; + BiosLinkerFileEntry file = { g_strdup(file_name), file_blob}; + + assert(!(alloc_align & (alloc_align - 1))); + + assert(!bios_linker_find_file(linker, file_name)); + g_array_append_val(linker->file_list, file); + + memset(&entry, 0, sizeof entry); + strncpy(entry.alloc.file, file_name, sizeof entry.alloc.file - 1); + entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ALLOCATE); + entry.alloc.align = cpu_to_le32(alloc_align); + entry.alloc.zone = alloc_fseg ? BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG : + BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH; + + /* Alloc entries must come first, so prepend them */ + g_array_prepend_vals(linker->cmd_blob, &entry, sizeof entry); +} + +/* + * bios_linker_loader_add_checksum: ask guest to add checksum of ACPI + * table in the specified file at the specified offset. + * + * Checksum calculation simply sums -X for each byte X in the range + * using 8-bit math (i.e. ACPI checksum). + * + * @linker: linker object instance + * @file: file that includes the checksum to be calculated + * and the data to be checksummed + * @start_offset, @size: range of data in the file to checksum, + * relative to the start of file blob + * @checksum_offset: location of the checksum to be patched within file blob, + * relative to the start of file blob + */ +void bios_linker_loader_add_checksum(BIOSLinker *linker, const char *file_name, + unsigned start_offset, unsigned size, + unsigned checksum_offset) +{ + BiosLinkerLoaderEntry entry; + const BiosLinkerFileEntry *file = bios_linker_find_file(linker, file_name); + + assert(file); + assert(start_offset < file->blob->len); + assert(start_offset + size <= file->blob->len); + assert(checksum_offset >= start_offset); + assert(checksum_offset + 1 <= start_offset + size); + + *(file->blob->data + checksum_offset) = 0; + memset(&entry, 0, sizeof entry); + strncpy(entry.cksum.file, file_name, sizeof entry.cksum.file - 1); + entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM); + entry.cksum.offset = cpu_to_le32(checksum_offset); + entry.cksum.start = cpu_to_le32(start_offset); + entry.cksum.length = cpu_to_le32(size); + + g_array_append_vals(linker->cmd_blob, &entry, sizeof entry); +} + +/* + * bios_linker_loader_add_pointer: ask guest to patch address in + * destination file with a pointer to source file + * + * @linker: linker object instance + * @dest_file: destination file that must be changed + * @dst_patched_offset: location within destination file blob to be patched + * with the pointer to @src_file+@src_offset (i.e. source + * blob allocated in guest memory + @src_offset), in bytes + * @dst_patched_offset_size: size of the pointer to be patched + * at @dst_patched_offset in @dest_file blob, in bytes + * @src_file: source file who's address must be taken + * @src_offset: location within source file blob to which + * @dest_file+@dst_patched_offset will point to after + * firmware's executed ADD_POINTER command + */ +void bios_linker_loader_add_pointer(BIOSLinker *linker, + const char *dest_file, + uint32_t dst_patched_offset, + uint8_t dst_patched_size, + const char *src_file, + uint32_t src_offset) +{ + uint64_t le_src_offset; + BiosLinkerLoaderEntry entry; + const BiosLinkerFileEntry *dst_file = + bios_linker_find_file(linker, dest_file); + const BiosLinkerFileEntry *source_file = + bios_linker_find_file(linker, src_file); + + assert(dst_file); + assert(source_file); + assert(dst_patched_offset < dst_file->blob->len); + assert(dst_patched_offset + dst_patched_size <= dst_file->blob->len); + assert(src_offset < source_file->blob->len); + + memset(&entry, 0, sizeof entry); + strncpy(entry.pointer.dest_file, dest_file, + sizeof entry.pointer.dest_file - 1); + strncpy(entry.pointer.src_file, src_file, + sizeof entry.pointer.src_file - 1); + entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_POINTER); + entry.pointer.offset = cpu_to_le32(dst_patched_offset); + entry.pointer.size = dst_patched_size; + assert(dst_patched_size == 1 || dst_patched_size == 2 || + dst_patched_size == 4 || dst_patched_size == 8); + + le_src_offset = cpu_to_le64(src_offset); + memcpy(dst_file->blob->data + dst_patched_offset, + &le_src_offset, dst_patched_size); + + g_array_append_vals(linker->cmd_blob, &entry, sizeof entry); +} + +/* + * bios_linker_loader_write_pointer: ask guest to write a pointer to the + * source file into the destination file, and write it back to QEMU via + * fw_cfg DMA. + * + * @linker: linker object instance + * @dest_file: destination file that must be written + * @dst_patched_offset: location within destination file blob to be patched + * with the pointer to @src_file, in bytes + * @dst_patched_offset_size: size of the pointer to be patched + * at @dst_patched_offset in @dest_file blob, in bytes + * @src_file: source file who's address must be taken + * @src_offset: location within source file blob to which + * @dest_file+@dst_patched_offset will point to after + * firmware's executed WRITE_POINTER command + */ +void bios_linker_loader_write_pointer(BIOSLinker *linker, + const char *dest_file, + uint32_t dst_patched_offset, + uint8_t dst_patched_size, + const char *src_file, + uint32_t src_offset) +{ + BiosLinkerLoaderEntry entry; + const BiosLinkerFileEntry *source_file = + bios_linker_find_file(linker, src_file); + + assert(source_file); + assert(src_offset < source_file->blob->len); + memset(&entry, 0, sizeof entry); + strncpy(entry.wr_pointer.dest_file, dest_file, + sizeof entry.wr_pointer.dest_file - 1); + strncpy(entry.wr_pointer.src_file, src_file, + sizeof entry.wr_pointer.src_file - 1); + entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_WRITE_POINTER); + entry.wr_pointer.dst_offset = cpu_to_le32(dst_patched_offset); + entry.wr_pointer.src_offset = cpu_to_le32(src_offset); + entry.wr_pointer.size = dst_patched_size; + assert(dst_patched_size == 1 || dst_patched_size == 2 || + dst_patched_size == 4 || dst_patched_size == 8); + + g_array_append_vals(linker->cmd_blob, &entry, sizeof entry); +} |