This patch adds the ability to load and link ACPI tables provided by QEMU. QEMU tells guests how to load and patch ACPI tables through its fw_cfg interface, by adding a firmware file 'etc/table-loader'. Guests are supposed to parse this file and execute corresponding QEMU commands.
Signed-off-by: Miao Yan yanmiaobest@gmail.com --- Changes in v2: - add function comment - improve error handling
arch/x86/cpu/qemu/fw_cfg.c | 253 ++++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/fw_cfg.h | 61 ++++++++++ arch/x86/lib/acpi_table.c | 4 + 3 files changed, 318 insertions(+)
diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c index bcd34af..5ea7a6e 100644 --- a/arch/x86/cpu/qemu/fw_cfg.c +++ b/arch/x86/cpu/qemu/fw_cfg.c @@ -10,7 +10,10 @@ #include <malloc.h> #include <asm/io.h> #include <asm/fw_cfg.h> +#include <asm/tables.h> +#include <asm/e820.h> #include <linux/list.h> +#include <memalign.h>
static bool fwcfg_present; static bool fwcfg_dma_present; @@ -204,6 +207,256 @@ err: return -ENOMEM; }
+#ifdef CONFIG_QEMU_ACPI_TABLE +static struct fw_file *qemu_fwcfg_find_file(const char *name) +{ + struct list_head *entry; + struct fw_file *file; + + list_for_each(entry, &fw_list) { + file = list_entry(entry, struct fw_file, list); + if (!strcmp(file->cfg.name, name)) + return file; + } + + return NULL; +} + +/* + * This function allocates memory for ACPI tables + * + * @entry : BIOS linker command entry which tells where to allocate memory + * (either high memory or low memory) + * @addr : The address that should be used for low memory allcation. If the + * memory allocation request is 'ZONE_HIGH' then this parameter will + * be ignored. + * @return: 0 on success, or negative value on failure + */ +static int bios_linker_allocate(struct bios_linker_entry *entry, + unsigned long *addr) +{ + uint32_t size, align; + struct fw_file *file; + unsigned long aligned_addr; + + align = le32_to_cpu(entry->alloc.align); + /* align must be power of 2 */ + if (align & (align - 1)) { + printf("error: wrong alignment %u\n", align); + return -EINVAL; + } + + file = qemu_fwcfg_find_file(entry->alloc.file); + if (!file) { + printf("error: can't find file %s\n", entry->alloc.file); + return -ENOENT; + } + + size = be32_to_cpu(file->cfg.size); + + /* + * ZONE_HIGH means we need to allocate from high memory, since + * malloc space is already at the end of RAM, so we directly use it. + * If allocation zone is ZONE_FSEG, then we use the 'addr' passed + * in which is low memory + */ + if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH) { + aligned_addr = (unsigned long)memalign(align, size); + if (!aligned_addr) { + printf("error: allocating resource\n"); + return -ENOMEM; + } + } else if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG) { + aligned_addr = ALIGN(*addr, align); + } else { + printf("error: invalid allocation zone\n"); + return -EINVAL; + } + + debug("bios_linker_allocate: allocate file %s, size %u, zone %d, align %u, addr 0x%lx\n", + file->cfg.name, size, entry->alloc.zone, align, aligned_addr); + + qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select), + size, (void *)aligned_addr); + file->addr = aligned_addr; + + /* adjust address for low memory allocation */ + if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG) + *addr = (aligned_addr + size); + + return 0; +} + +/* + * This function patches ACPI tables previously loaded + * by bios_linker_allocate() + * + * @entry : BIOS linker command entry which tells how to patch + * ACPI tables + * @return: 0 on success, or negative value on failure + */ +static int bios_linker_add_pointer(struct bios_linker_entry *entry) +{ + struct fw_file *dest, *src; + uint32_t offset = le32_to_cpu(entry->pointer.offset); + uint64_t pointer = 0; + + dest = qemu_fwcfg_find_file(entry->pointer.dest_file); + if (!dest || !dest->addr) + return -ENOENT; + src = qemu_fwcfg_find_file(entry->pointer.src_file); + if (!src || !src->addr) + return -ENOENT; + + debug("bios_linker_add_pointer: dest->addr 0x%lx, src->addr 0x%lx, offset 0x%x size %u, 0x%llx\n", + dest->addr, src->addr, offset, entry->pointer.size, pointer); + + memcpy(&pointer, (char *)dest->addr + offset, entry->pointer.size); + pointer = le64_to_cpu(pointer); + pointer += (unsigned long)src->addr; + pointer = cpu_to_le64(pointer); + memcpy((char *)dest->addr + offset, &pointer, entry->pointer.size); + + return 0; +} + +/* + * This function updates checksum fields of ACPI tables previously loaded + * by bios_linker_allocate() + * + * @entry : BIOS linker command entry which tells where to update ACPI table + * checksums + * @return: 0 on success, or negative value on failure + */ +static int bios_linker_add_checksum(struct bios_linker_entry *entry) +{ + struct fw_file *file; + uint8_t *data, cksum = 0; + uint8_t *cksum_start; + + file = qemu_fwcfg_find_file(entry->cksum.file); + if (!file || !file->addr) + return -ENOENT; + + data = (uint8_t *)(file->addr + le32_to_cpu(entry->cksum.offset)); + cksum_start = (uint8_t *)(file->addr + le32_to_cpu(entry->cksum.start)); + cksum = table_compute_checksum(cksum_start, + le32_to_cpu(entry->cksum.length)); + *data = cksum; + + return 0; +} + +unsigned install_e820_map(unsigned max_entries, struct e820entry *entries) +{ + entries[0].addr = 0; + entries[0].size = ISA_START_ADDRESS; + entries[0].type = E820_RAM; + + entries[1].addr = ISA_START_ADDRESS; + entries[1].size = ISA_END_ADDRESS - ISA_START_ADDRESS; + entries[1].type = E820_RESERVED; + + /* + * since we use memalign(malloc) to allocate high memory for + * storing ACPI tables, we need to reserve them in e820 tables, + * otherwise kernel will reclaim them and data will be corrupted + */ + entries[2].addr = ISA_END_ADDRESS; + entries[2].size = gd->relocaddr - TOTAL_MALLOC_LEN - ISA_END_ADDRESS; + entries[2].type = E820_RAM; + + /* for simplicity, reserve entire malloc space */ + entries[3].addr = gd->relocaddr - TOTAL_MALLOC_LEN; + entries[3].size = TOTAL_MALLOC_LEN; + entries[3].type = E820_RESERVED; + + entries[4].addr = gd->relocaddr; + entries[4].size = gd->ram_size - gd->relocaddr; + entries[4].type = E820_RESERVED; + + entries[5].addr = CONFIG_PCIE_ECAM_BASE; + entries[5].size = CONFIG_PCIE_ECAM_SIZE; + entries[5].type = E820_RESERVED; + + return 6; +} + +/* This function loads and patches ACPI tables provided by QEMU */ +unsigned long write_acpi_tables(unsigned long addr) +{ + int i, ret = 0; + struct fw_file *file; + struct bios_linker_entry *table_loader; + struct bios_linker_entry *entry; + uint32_t size; + struct list_head *list; + + /* make sure fw_list is loaded */ + ret = qemu_fwcfg_read_firmware_list(); + if (ret) { + printf("error: can't read firmware file list\n"); + return addr; + } + + file = qemu_fwcfg_find_file("etc/table-loader"); + if (!file) { + printf("error: can't find etc/table-loader\n"); + return addr; + } + + size = be32_to_cpu(file->cfg.size); + if ((size % sizeof(*entry)) != 0) { + printf("error: table-loader maybe corrupted\n"); + return addr; + } + + table_loader = malloc(size); + if (!table_loader) { + printf("error: no memory for table-loader\n"); + return addr; + } + + qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select), + size, table_loader); + + for (i = 0; i < (size / sizeof(*entry)); i++) { + entry = table_loader + i; + switch (le32_to_cpu(entry->command)) { + case BIOS_LINKER_LOADER_COMMAND_ALLOCATE: + ret = bios_linker_allocate(entry, &addr); + if (ret) + goto out; + break; + case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER: + ret = bios_linker_add_pointer(entry); + if (ret) + goto out; + break; + case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM: + ret = bios_linker_add_checksum(entry); + if (ret) + goto out; + break; + default: + break; + } + } + +out: + if (ret) { + list_for_each(list, &fw_list) { + file = list_entry(list, struct fw_file, list); + if (file->addr) + free((void *)file->addr); + } + } + + free(table_loader); + return addr; +} +#endif + static int qemu_fwcfg_list_firmware(void) { int ret; diff --git a/arch/x86/include/asm/fw_cfg.h b/arch/x86/include/asm/fw_cfg.h index 2acf43e..e9450c6 100644 --- a/arch/x86/include/asm/fw_cfg.h +++ b/arch/x86/include/asm/fw_cfg.h @@ -47,11 +47,23 @@ enum qemu_fwcfg_items { FW_CFG_INVALID = 0xffff, };
+enum { + BIOS_LINKER_LOADER_COMMAND_ALLOCATE = 0x1, + BIOS_LINKER_LOADER_COMMAND_ADD_POINTER = 0x2, + BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3, +}; + +enum { + BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1, + BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2, +}; + #define FW_CFG_FILE_SLOTS 0x10 #define FW_CFG_MAX_ENTRY (FW_CFG_FILE_FIRST + FW_CFG_FILE_SLOTS) #define FW_CFG_ENTRY_MASK ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
#define FW_CFG_MAX_FILE_PATH 56 +#define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH
#define QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
@@ -81,6 +93,55 @@ struct fw_cfg_dma_access { __be64 address; };
+struct bios_linker_entry { + __le32 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]; + __le32 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]; + __le32 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]; + __le32 offset; + __le32 start; + __le32 length; + } cksum; + + /* padding */ + char pad[124]; + }; +} __packed; + /** * Initialize QEMU fw_cfg interface */ diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index ab1db7e..2ec5ad2 100644 --- a/arch/x86/lib/acpi_table.c +++ b/arch/x86/lib/acpi_table.c @@ -331,6 +331,10 @@ static void acpi_create_ssdt_generator(acpi_header_t *ssdt, ssdt->checksum = table_compute_checksum((void *)ssdt, ssdt->length); }
+/* + * QEMU's version of write_acpi_tables is defined in + * arch/x86/cpu/qemu/fw_cfg.c + */ unsigned long write_acpi_tables(unsigned long start) { unsigned long current;