[U-Boot] [PATCH v3 1/8] x86: qemu: add fw_cfg support

Miao Yan yanmiaobest at gmail.com
Wed Dec 30 09:44:37 CET 2015


Hi Bin,

2015-12-30 12:04 GMT+08:00 Bin Meng <bmeng.cn at gmail.com>:
> Hi Miao,
>
> On Tue, Dec 29, 2015 at 6:35 PM, Miao Yan <yanmiaobest at gmail.com> wrote:
>> The QEMU fw_cfg interface allows the guest to retrieve various
>> data information from QEMU. For example, APCI/SMBios tables, number
>> of online cpus, kernel data and command line, etc.
>>
>> This patch adds support for QEMU fw_cfg interface.
>>
>> Signed-off-by: Miao Yan <yanmiaobest at gmail.com>
>> ---
>> Changes in v2:
>>   - rewrite command handling logic
>>   - various cleanups
>>
>> Changes in v3:
>>   - fix an error in do_qemu_fw()
>>
>>  arch/x86/cpu/qemu/Makefile |   2 +-
>>  arch/x86/cpu/qemu/fw_cfg.c | 241 +++++++++++++++++++++++++++++++++++++++++++++
>>  arch/x86/cpu/qemu/fw_cfg.h |  97 ++++++++++++++++++
>>  arch/x86/cpu/qemu/qemu.c   |   3 +
>>  4 files changed, 342 insertions(+), 1 deletion(-)
>>  create mode 100644 arch/x86/cpu/qemu/fw_cfg.c
>>  create mode 100644 arch/x86/cpu/qemu/fw_cfg.h
>>
>> diff --git a/arch/x86/cpu/qemu/Makefile b/arch/x86/cpu/qemu/Makefile
>> index 3f3958a..ad424ec 100644
>> --- a/arch/x86/cpu/qemu/Makefile
>> +++ b/arch/x86/cpu/qemu/Makefile
>> @@ -7,5 +7,5 @@
>>  ifndef CONFIG_EFI_STUB
>>  obj-y += car.o dram.o
>>  endif
>> -obj-y += qemu.o
>> +obj-y += qemu.o fw_cfg.o
>>  obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi.o dsdt.o
>> diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c
>> new file mode 100644
>> index 0000000..bb6a11e
>> --- /dev/null
>> +++ b/arch/x86/cpu/qemu/fw_cfg.c
>> @@ -0,0 +1,241 @@
>> +/*
>> + * (C) Copyright 2015 Miao Yan <yanmiaoebst at gmail.com>
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <command.h>
>> +#include <errno.h>
>> +#include <malloc.h>
>> +#include <asm/io.h>
>> +#include "fw_cfg.h"
>> +
>> +static bool fwcfg_present;
>> +static bool fwcfg_dma_present;
>> +
>> +static void qemu_fwcfg_read_entry_pio(uint16_t entry,
>> +               uint32_t size, void *address)
>> +{
>> +       uint32_t i = 0;
>> +       uint8_t *data = address;
>> +
>> +       if (entry != FW_CFG_INVALID)
>
> As we discussed in the v1 thread, can you please put a comment block
> here to describe the QEMU internals (ie: what happens if entry ==
> FW_CFG_INVALID)?
>
>> +               outw(entry, FW_CONTROL_PORT);
>> +       while (size--)
>> +               data[i++] = inb(FW_DATA_PORT);
>> +}
>> +
>> +static void qemu_fwcfg_read_entry_dma(uint16_t entry,
>> +               uint32_t size, void *address)
>> +{
>> +       struct fw_cfg_dma_access dma;
>> +
>> +       dma.length = cpu_to_be32(size);
>> +       dma.address = cpu_to_be64((uintptr_t)address);
>> +       dma.control = cpu_to_be32(FW_CFG_DMA_READ);
>> +       if (entry != FW_CFG_INVALID)
>
> ditto.
>
>> +               dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
>> +
>> +       barrier();
>> +
>> +       debug("qemu_fwcfg_dma_read_entry: addr %p, length %u control 0x%x\n",
>> +             address, size, be32_to_cpu(dma.control));
>> +
>> +       outl(cpu_to_be32((uint32_t)&dma), FW_DMA_PORT_HIGH);
>> +
>> +       while (dma.control & ~FW_CFG_DMA_ERROR)
>> +               __asm__ __volatile__ ("pause");
>
> For some reason, with the v3 patch U-Boot hangs here. I changed to use
> pio to read the entry then U-Boot can boot. Can you please check this?

Removing some checks in v3 exposed a bug with older qemu versions. I'll
fix this.


>
>> +}
>> +
>> +static bool qemu_fwcfg_present(void)
>> +{
>> +       uint32_t qemu;
>> +
>> +       qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
>> +       return be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE;
>> +}
>> +
>> +static bool qemu_fwcfg_dma_present(void)
>> +{
>> +       uint8_t dma_enabled;
>> +
>> +       qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
>> +       if (dma_enabled & FW_CFG_DMA_ENABLED)
>> +               return 1;
>
> return true;
>
>> +
>> +       return 0;
>
> return false;
>
>> +}
>> +
>> +static void qemu_fwcfg_read_entry(uint16_t entry,
>> +               uint32_t length, void *address)
>> +{
>> +       if (fwcfg_dma_present)
>> +               qemu_fwcfg_read_entry_dma(entry, length, address);
>> +       else
>> +               qemu_fwcfg_read_entry_pio(entry, length, address);
>> +}
>> +
>> +int qemu_fwcfg_online_cpus(void)
>> +{
>> +       uint16_t nb_cpus;
>> +
>> +       if (!fwcfg_present)
>> +               return 1;
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
>> +
>> +       return le16_to_cpu(nb_cpus);
>> +}
>> +
>> +static int qemu_fwcfg_setup_kernel(void *load_addr)
>> +{
>> +       char *data_addr;
>> +       uint32_t setup_size, kernel_size, cmdline_size, initrd_size;
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_SETUP_SIZE, 4, &setup_size);
>> +       qemu_fwcfg_read_entry(FW_CFG_KERNEL_SIZE, 4, &kernel_size);
>> +
>> +       if (setup_size == 0 || kernel_size == 0) {
>> +               printf("warning: no kernel available\n");
>> +               return -1;
>> +       }
>> +
>> +       data_addr = load_addr;
>> +       qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA,
>> +                             le32_to_cpu(setup_size), data_addr);
>> +       data_addr += le32_to_cpu(setup_size);
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA,
>> +                             le32_to_cpu(kernel_size), data_addr);
>> +       data_addr += le32_to_cpu(kernel_size);
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_INITRD_SIZE, 4, &initrd_size);
>> +       if (initrd_size == 0) {
>> +               printf("warning: no initrd available\n");
>> +       } else {
>> +               qemu_fwcfg_read_entry(FW_CFG_INITRD_DATA,
>> +                                     le32_to_cpu(initrd_size), data_addr);
>> +               data_addr += le32_to_cpu(initrd_size);
>> +       }
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
>> +       qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA,
>> +                             le32_to_cpu(cmdline_size), data_addr);
>> +
>> +       printf("loading kernel to address %p", load_addr);
>> +       if (initrd_size)
>> +               printf(" initrd %p\n",
>> +                      (char *)load_addr +
>> +                      le32_to_cpu(setup_size) +
>> +                      le32_to_cpu(kernel_size));
>> +       else
>> +               printf("\n");
>> +
>> +       return setenv("bootargs", data_addr);
>> +}
>> +
>> +static int qemu_fwcfg_list_firmware(void)
>> +{
>> +       int i;
>> +       uint32_t count;
>> +       struct fw_cfg_files *files;
>> +
>> +       qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
>> +       if (!count)
>> +               return 0;
>> +
>> +       count = be32_to_cpu(count);
>> +       files = malloc(count * sizeof(struct fw_cfg_file));
>> +       if (!files)
>> +               return -ENOMEM;
>> +
>> +       files->count = count;
>> +       qemu_fwcfg_read_entry(FW_CFG_INVALID,
>> +                             count * sizeof(struct fw_cfg_file),
>> +                             files->files);
>> +
>> +       for (i = 0; i < files->count; i++)
>> +               printf("%-56s\n", files->files[i].name);
>> +       free(files);
>> +       return 0;
>> +}
>> +
>> +void qemu_fwcfg_init(void)
>> +{
>> +       fwcfg_present = qemu_fwcfg_present();
>> +       if (fwcfg_present)
>> +               fwcfg_dma_present = qemu_fwcfg_dma_present();
>> +}
>> +
>> +static int qemu_fwcfg_do_list(cmd_tbl_t *cmdtp, int flag,
>> +               int argc, char * const argv[])
>> +{
>> +       qemu_fwcfg_list_firmware();
>> +
>> +       return 0;
>> +}
>> +
>> +static int qemu_fwcfg_do_cpus(cmd_tbl_t *cmdtp, int flag,
>> +               int argc, char * const argv[])
>> +{
>> +       printf("%d cpu(s) online\n", qemu_fwcfg_online_cpus());
>> +
>> +       return 0;
>> +}
>> +
>> +static int qemu_fwcfg_do_load(cmd_tbl_t *cmdtp, int flag,
>> +               int argc, char * const argv[])
>> +{
>> +       void *load_addr;
>> +
>> +       if (argc == 1) {
>> +               load_addr = (void *)simple_strtoul(argv[0], NULL, 16);
>> +       } else {
>> +               load_addr = getenv("loadaddr");
>> +               if (!load_addr)
>> +                       load_addr = (void *)CONFIG_SYS_LOAD_ADDR;
>> +               else
>> +                       load_addr = (void *)simple_strtoul(load_addr,
>> +                                                          NULL, 16);
>> +       }
>> +
>> +       return qemu_fwcfg_setup_kernel(load_addr);
>> +}
>> +
>> +static cmd_tbl_t fwcfg_commands[] = {
>> +       U_BOOT_CMD_MKENT(list, 0, 1, qemu_fwcfg_do_list, "", ""),
>> +       U_BOOT_CMD_MKENT(cpus, 0, 1, qemu_fwcfg_do_cpus, "", ""),
>> +       U_BOOT_CMD_MKENT(load, 1, 1, qemu_fwcfg_do_load, "", ""),
>> +};
>> +
>> +int do_qemu_fw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>> +{
>> +       int ret;
>> +       cmd_tbl_t *fwcfg_cmd;
>> +
>> +       if (!fwcfg_present) {
>> +               printf("QEMU fw_cfg interface not found\n");
>> +               return CMD_RET_USAGE;
>> +       }
>> +
>> +       fwcfg_cmd = find_cmd_tbl(argv[1], fwcfg_commands,
>> +                                ARRAY_SIZE(fwcfg_commands));
>> +       argc -= 2;
>> +       argv += 2;
>> +       if (!fwcfg_cmd || argc > fwcfg_cmd->maxargs)
>> +               return CMD_RET_USAGE;
>> +
>> +       ret = fwcfg_cmd->cmd(fwcfg_cmd, flag, argc, argv);
>> +
>> +       return cmd_process_error(fwcfg_cmd, ret);
>> +}
>> +
>> +U_BOOT_CMD(
>> +       fw,     3,      1,      do_qemu_fw,
>> +       "QEMU firmware interface",
>> +       "<command>\n"
>> +       "    - list        : print firmware(s) currently loaded\n"
>> +       "    - cpus        : print online cpu number\n"
>> +       "    - load <addr> : load kernel (if any) to address <addr>, and setup for zboot\n"
>> +)
>> diff --git a/arch/x86/cpu/qemu/fw_cfg.h b/arch/x86/cpu/qemu/fw_cfg.h
>> new file mode 100644
>> index 0000000..f3d06d1
>> --- /dev/null
>> +++ b/arch/x86/cpu/qemu/fw_cfg.h
>> @@ -0,0 +1,97 @@
>> +/*
>> + * (C) Copyright 2015 Miao Yan <yanmiaobest at gmail.com>
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#ifndef __FW_CFG__
>> +#define __FW_CFG__
>> +
>> +#define FW_CONTROL_PORT         0x510
>> +#define FW_DATA_PORT            0x511
>> +#define FW_DMA_PORT_LOW         0x514
>> +#define FW_DMA_PORT_HIGH        0x518
>
> Please use tab after the macro name. Please fix this globally in this series.
>
>> +
>> +enum qemu_fwcfg_items {
>> +       FW_CFG_SIGNATURE       = 0x00,
>> +       FW_CFG_ID              = 0x01,
>> +       FW_CFG_UUID            = 0x02,
>> +       FW_CFG_RAM_SIZE        = 0x03,
>> +       FW_CFG_NOGRAPHIC       = 0x04,
>> +       FW_CFG_NB_CPUS         = 0x05,
>> +       FW_CFG_MACHINE_ID      = 0x06,
>> +       FW_CFG_KERNEL_ADDR     = 0x07,
>> +       FW_CFG_KERNEL_SIZE     = 0x08,
>> +       FW_CFG_KERNEL_CMDLINE  = 0x09,
>> +       FW_CFG_INITRD_ADDR     = 0x0a,
>> +       FW_CFG_INITRD_SIZE     = 0x0b,
>> +       FW_CFG_BOOT_DEVICE     = 0x0c,
>> +       FW_CFG_NUMA            = 0x0d,
>> +       FW_CFG_BOOT_MENU       = 0x0e,
>> +       FW_CFG_MAX_CPUS        = 0x0f,
>> +       FW_CFG_KERNEL_ENTRY    = 0x10,
>> +       FW_CFG_KERNEL_DATA     = 0x11,
>> +       FW_CFG_INITRD_DATA     = 0x12,
>> +       FW_CFG_CMDLINE_ADDR    = 0x13,
>> +       FW_CFG_CMDLINE_SIZE    = 0x14,
>> +       FW_CFG_CMDLINE_DATA    = 0x15,
>> +       FW_CFG_SETUP_ADDR      = 0x16,
>> +       FW_CFG_SETUP_SIZE      = 0x17,
>> +       FW_CFG_SETUP_DATA      = 0x18,
>> +       FW_CFG_FILE_DIR        = 0x19,
>> +       FW_CFG_FILE_FIRST      = 0x20,
>> +       FW_CFG_FILE_SLOTS      = 0x10,
>
> FW_CFG_FILE_SLOTS should not be a member of enum qemu_fwcfg_items as
> it describes the number of files.
>
>> +       FW_CFG_WRITE_CHANNEL   = 0x4000,
>> +       FW_CFG_ARCH_LOCAL      = 0x8000,
>> +       FW_CFG_INVALID         = 0xffff,
>> +};
>> +
>> +#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 QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
>> +
>> +#define FW_CFG_DMA_ERROR  (0x1 << 0)
>
> 0x1 -> 1
>
>> +#define FW_CFG_DMA_READ   (0x1 << 1)
>> +#define FW_CFG_DMA_SKIP   (0x1 << 2)
>> +#define FW_CFG_DMA_SELECT (0x1 << 3)
>> +
>> +#define FW_CFG_DMA_ENABLED      0x1
>
> (1 << 0)
>
>> +
>> +struct fw_cfg_file {
>> +       __be32 size;
>> +       __be16 select;
>> +       __be16 reserved;
>> +       char name[FW_CFG_MAX_FILE_PATH];
>> +};
>> +
>> +struct fw_cfg_files {
>> +       __be32 count;
>> +       struct fw_cfg_file files[];
>> +};
>> +
>> +struct fw_cfg_dma_access {
>> +       __be32 control;
>> +       __be32 length;
>> +       __be64 address;
>> +};
>> +
>> +/**
>> + * Initialize QEMU fw_cfg interface
>> + *
>> + * @retval:   None
>
> @return
>
>> + */
>> +
>> +void qemu_fwcfg_init(void);
>> +
>> +/**
>> + * Get system cpu number
>> + *
>> + * @retval:   cpu number in system
>
> @return
>
>> + */
>> +
>> +int qemu_fwcfg_online_cpus(void);
>> +
>> +#endif
>> diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c
>> index 1f93f72..d9ae066 100644
>> --- a/arch/x86/cpu/qemu/qemu.c
>> +++ b/arch/x86/cpu/qemu/qemu.c
>> @@ -11,6 +11,7 @@
>>  #include <asm/processor.h>
>>  #include <asm/arch/device.h>
>>  #include <asm/arch/qemu.h>
>> +#include "fw_cfg.h"
>>
>>  static bool i440fx;
>>
>> @@ -57,6 +58,8 @@ static void qemu_chipset_init(void)
>>                 x86_pci_write_config32(PCI_BDF(0, 0, 0), PCIEX_BAR,
>>                                        CONFIG_PCIE_ECAM_BASE | BAR_EN);
>>         }
>> +
>> +       qemu_fwcfg_init();
>>  }
>>
>>  int arch_cpu_init(void)
>> --
>
> Regards,
> Bin


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