[U-Boot] [PATCH 3/4] x86: qemu: add the ability to load and link ACPI tables from QEMU
Miao Yan
yanmiaobest at gmail.com
Tue Jan 19 03:39:04 CET 2016
Hi Bin,
2016-01-16 21:24 GMT+08:00 Bin Meng <bmeng.cn at gmail.com>:
> Hi Miao,
>
> On Fri, Jan 15, 2016 at 11:12 AM, Miao Yan <yanmiaobest at gmail.com> wrote:
>> 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 at gmail.com>
>> ---
>> arch/x86/cpu/qemu/fw_cfg.c | 214 ++++++++++++++++++++++++++++++++++++++++++
>> arch/x86/include/asm/fw_cfg.h | 70 ++++++++++++++
>> 2 files changed, 284 insertions(+)
>>
>> diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c
>> index b22026c..755676c 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;
>> @@ -202,6 +205,217 @@ err:
>> return -ENOMEM;
>> }
>>
>> +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;
>> +}
>> +
>> +static int bios_linker_allocate(struct bios_linker_entry *entry,
>> + unsigned long *addr)
>
> Please add a comment block for what this function is doing, its
> parameters, return value, etc. Please do the same for the other 2
> functions below.
>
>> +{
>> + 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);
>> + } 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;
>> +}
>> +
>> +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;
>> +
>
> Remove one blank line here.
>
>> +
>> + memcpy(&pointer, (char *)dest->addr + offset, entry->pointer.size);
>> + pointer = le64_to_cpu(pointer);
>> +
>
> Remove one blank line here.
>
>> +
>> + 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);
>> +
>> + pointer += (unsigned long)src->addr;
>> + pointer = cpu_to_le64(pointer);
>> + memcpy((char *)dest->addr + offset, &pointer, entry->pointer.size);
>> +
>> + return 0;
>> +}
>> +
>> +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 qemu_fwcfg_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;
>> +
>> + /* 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");
>
> table-loader may be
>
>> + 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 err;
>> + break;
>> + case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER:
>> + ret = bios_linker_add_pointer(entry);
>> + if (ret)
>> + goto err;
>> + break;
>> + case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM:
>> + ret = bios_linker_add_checksum(entry);
>> + if (ret)
>> + goto err;
>> + break;
>> + default:
>> + break;
>> + }
>> + }
>> +err:
>> + free(table_loader);
>> + return addr;
>> +}
>> +
>> 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 285d805..ad58205 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
>
> Use FW_CFG_MAX_FILE_PATH directly?
Those codes are derived from QEMU, with some modifications to make
them compatible with U-Boot source. So I think maybe we should keep it
in sync with QEMU.
>
>>
>> #define QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
>>
>> @@ -69,6 +81,7 @@ struct fw_cfg_file {
>> char name[FW_CFG_MAX_FILE_PATH];
>> };
>>
>> +
>> struct fw_file {
>> struct fw_cfg_file cfg;
>> unsigned long addr;
>> @@ -86,6 +99,55 @@ 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];
>
> Use FW_CFG_MAX_FILE_PATH directly?
>
>> + __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
>> */
>> @@ -98,4 +160,12 @@ void qemu_fwcfg_init(void);
>> */
>> int qemu_fwcfg_online_cpus(void);
>>
>> +/**
>> + * Load ACPI tables from QEMU
>> + *
>> + * @addr: address to load
>> + * @return: next address
>> + */
>> +unsigned long qemu_fwcfg_write_acpi_tables(unsigned long addr);
>> +
>> #endif
>> --
>
> Regards,
> Bin
More information about the U-Boot
mailing list