[U-Boot] [PATCH 3/4] x86: qemu: add the ability to load and link ACPI tables from QEMU
Bin Meng
bmeng.cn at gmail.com
Tue Jan 19 10:25:46 CET 2016
Hi Miao,
On Tue, Jan 19, 2016 at 10:39 AM, Miao Yan <yanmiaobest at gmail.com> wrote:
> 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.
>
>
OK, makes sense.
>>
>>>
>>> #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