[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
Sat Jan 16 14:24:35 CET 2016
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?
>
> #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